54 results on '"Jansen CC"'
Search Results
2. Comparison of performance of four instruments in evaluating the effects of salmeterol on asthma quality of life
- Author
-
Rutten-van Molken, MP, primary, Custers, F, additional, van Doorslaer, EK, additional, Jansen, CC, additional, Heurman, L, additional, Maesen, FP, additional, Smeets, JJ, additional, Bommer, AM, additional, and Raaijmakers, JA, additional more...
- Published
- 1995
- Full Text
- View/download PDF
Catalog
3. First Isolation of Japanese Encephalitis Virus Genotype IV from Mosquitoes in Australia.
- Author
-
Pyke AT, Burtonclay P, Poudel N, Ingall W, Nair N, Hall-Mendelin S, Craig SB, Smith C, Wang W, Darbro JM, Jansen CC, and van den Hurk AF
- Subjects
- Animals, Australia epidemiology, Mosquito Vectors virology, Swine, Queensland epidemiology, Encephalitis, Japanese virology, Encephalitis, Japanese veterinary, Encephalitis, Japanese epidemiology, RNA, Viral genetics, Humans, Encephalitis Virus, Japanese genetics, Encephalitis Virus, Japanese isolation & purification, Encephalitis Virus, Japanese classification, Culicidae virology, Genotype, Phylogeny
- Abstract
Introduction: Widespread transmission of Japanese encephalitis virus (JEV) genotype four (GIV) occurred across mainland Australia in 2022. This resulted in forty-five human cases, including seven deaths, and the identification of JEV infection in over 80 commercial piggeries. Materials and Methods: We collected mosquitoes which were trapped using CO
2 -baited light traps deployed near piggeries reporting disease or in regions linked to human cases in the Wide Bay region in the state of Queensland. Mosquitoes from four traps yielded JEV RNA by real-time RT-PCR. Pools containing RNA positive mosquitoes were inoculated onto mosquito cell monolayers. Discussion: A single isolate of JEV was obtained from a pool of mixed mosquito species. Near whole genome sequencing and phylogenetic analysis of the JEV isolate demonstrated its high genomic relatedness with JEV GIV pig sequences sampled from Queensland and the state of New South Wales in 2022. Conclusion: We report the first isolation of JEV GIV from mosquitoes collected in Australia. With only a few JEV GIV isolates available globally, the isolate we report will be essential for future research of JEV host interactions, evolution and disease markers, and development of effective therapies, vaccines, diagnostic assays, and mosquito control strategies. more...- Published
- 2024
- Full Text
- View/download PDF
4. Past and future epidemic potential of chikungunya virus in Australia.
- Author
-
White T, Mincham G, Montgomery BL, Jansen CC, Huang X, Williams CR, Flower RLP, Faddy HM, Frentiu FD, and Viennet E
- Subjects
- Aedes physiology, Aedes virology, Animals, Australia epidemiology, Bayes Theorem, Chikungunya Fever transmission, Chikungunya Fever virology, Chikungunya virus genetics, Epidemics, Female, Humans, Male, Mosquito Vectors physiology, Mosquito Vectors virology, Chikungunya Fever epidemiology, Chikungunya virus physiology
- Abstract
Background: Australia is theoretically at risk of epidemic chikungunya virus (CHIKV) activity as the principal vectors are present on the mainland Aedes aegypti) and some islands of the Torres Strait (Ae. aegypti and Ae. albopictus). Both vectors are highly invasive and adapted to urban environments with a capacity to expand their distributions into south-east Queensland and other states in Australia. We sought to estimate the epidemic potential of CHIKV, which is not currently endemic in Australia, by considering exclusively transmission by the established vector in Australia, Ae. aegypti, due to the historical relevance and anthropophilic nature of the vector., Methodology/principal Findings: We estimated the historical (1995-2019) epidemic potential of CHIKV in eleven Australian locations, including the Torres Strait, using a basic reproduction number equation. We found that the main urban centres of Northern Australia could sustain an epidemic of CHIKV. We then estimated future trends in epidemic potential for the main centres for the years 2020 to 2029. We also conducted uncertainty and sensitivity analyses on the variables comprising the basic reproduction number and found high sensitivity to mosquito population size, human population size, impact of vector control and human infectious period., Conclusions/significance: By estimating the epidemic potential for CHIKV transmission on mainland Australia and the Torres Strait, we identified key areas of focus for controlling vector populations and reducing human exposure. As the epidemic potential of the virus is estimated to rise towards 2029, a greater focus on control and prevention measures should be implemented in at-risk locations., Competing Interests: The authors have declared that no competing interests exist. more...
- Published
- 2021
- Full Text
- View/download PDF
5. Uncovering the genetic diversity within the Aedes notoscriptus virome and isolation of new viruses from this highly urbanised and invasive mosquito.
- Author
-
Pyke AT, Shivas MA, Darbro JM, Onn MB, Johnson PH, Crunkhorn A, Montgomery I, Burtonclay P, Jansen CC, and van den Hurk AF
- Abstract
The Australian backyard mosquito, Aedes notoscriptus , is a highly urbanised pest species that has invaded New Zealand and the USA. Importantly, Ae. notoscriptus has been implicated as a vector of Ross River virus, a common and arthritogenic arbovirus in Australia, and is a laboratory vector of numerous other pathogenic viruses, including West Nile, yellow fever, and Zika viruses. To further explore live viruses harboured by field populations of Ae. notoscriptus and, more specifically, assess the genetic diversity of its virome, we processed 495 pools, comprising a total of 6,674 female Ae. notoscriptus collected across fifteen suburbs in Brisbane, Australia, between January 2018 and May 2019. Nine virus isolates were recovered and characterised by metagenomic sequencing and phylogenetics. The principal viral family represented was Flaviviridae . Known viruses belonging to the genera Flavivirus, Orbivirus, Mesonivirus , and Nelorpivirus were identified together with two novel virus species, including a divergent Thogoto-like orthomyxovirus and an insect-specific flavivirus. Among these, we recovered three Stratford virus (STRV) isolates and an isolate of Wongorr virus (WGRV), which for these viral species is unprecedented for the geographical area of Brisbane. Thus, the documented geographical distribution of STRV and WGRV, both known for their respective medical and veterinary importance, has now been expanded to include this major urban centre. Phylogenies of the remaining five viruses, namely, Casuarina, Ngewotan, the novel Thogoto-like virus, and two new flavivirus species, suggested they are insect-specific viruses. None of these viruses have been previously associated with Ae. notoscriptus or been reported in Brisbane. These findings exemplify the rich genetic diversity and viral abundance within the Ae. notoscriptus virome and further highlight this species as a vector of concern with the potential to transmit viruses impacting human or animal health. Considering it is a common pest and vector in residential areas and is expanding its global distribution, ongoing surveillance, and ecological study of Ae. notoscriptus , together with mapping of its virome and phenotypic characterisation of isolated viruses, is clearly warranted. Immanently, these initiatives are essential for future understanding of both the mosquito virome and the evolution of individual viral species., (© The Author(s) 2021. Published by Oxford University Press.) more...
- Published
- 2021
- Full Text
- View/download PDF
6. Impact of COVID-19 Mitigation Measures on Mosquito-Borne Diseases in 2020 in Queensland, Australia.
- Author
-
Jansen CC, Darbro JM, Birrell FA, Shivas MA, and van den Hurk AF
- Subjects
- Alphavirus Infections epidemiology, Alphavirus Infections transmission, Animals, COVID-19 epidemiology, Communicable Disease Control methods, Communicable Disease Control statistics & numerical data, Culicidae virology, Disease Outbreaks statistics & numerical data, Humans, Movement, Queensland epidemiology, Travel, Vector Borne Diseases prevention & control, Vector Borne Diseases transmission, COVID-19 prevention & control, Disease Outbreaks prevention & control, Population Surveillance, Vector Borne Diseases epidemiology
- Abstract
We describe the impact of COVID-19 mitigation measures on mosquito-borne diseases in Queensland, Australia, during the first half of 2020. Implementation of restrictions coincided with an atypical late season outbreak of Ross River virus (RRV) characterized by a peak in notifications in April (1173) and May (955) which were greater than 3-fold the mean observed for the previous four years. We propose that limitations on human movement likely resulted in the majority of RRV infections being acquired at or near the place of residence, and that an increase in outdoor activities, such as gardening and bushwalking in the local household vicinity, increased risk of exposure to RRV-infected mosquitoes. In contrast, the precipitous decline in international passenger flights led to a reduction in the number of imported dengue and malaria cases of over 70% and 60%, respectively, compared with the previous five years. This substantial reduction in flights also reduced a risk pathway for importation of exotic mosquitoes, but the risk posed by importation via sea cargo was not affected. Overall, the emergence of COVID-19 has had a varied impact on mosquito-borne disease epidemiology in Queensland, but the need for mosquito surveillance and control, together with encouragement of personal protective measures, remains unchanged. more...
- Published
- 2021
- Full Text
- View/download PDF
7. Simulating an invasion: unsealed water storage (rainwater tanks) and urban block design facilitate the spread of the dengue fever mosquito, Aedes aegypti, in Brisbane, Australia.
- Author
-
Trewin BJ, Parry HR, Pagendam DE, Devine GJ, Zalucki MP, Darbro JM, Jansen CC, and Schellhorn NA
- Abstract
Aedes aegypti (Linnaeus) was once highly prevalent across eastern Australia, resulting in epidemics of dengue fever. Drought conditions have led to a rapid rise in semi-permanent, urban water storage containers called rainwater tanks known to be critical larval habitat for the species. The presence of these larval habitats has increased the risk of establishment of highly urbanised, invasive mosquito vectors such as Ae. aegypti . Here we use a spatially explicit network model to examine the role that unsealed rainwater tanks may play in population connectivity of an Ae. aegypti invasion in suburbs of Brisbane, a major Australian city. We characterise movement between rainwater tanks as a diffusion-like process, limited by a maximum distance of movement, average life expectancy, and a probability that Ae. aegypti will cross wide open spaces such as roads. The simulation model was run against a number of scenarios that examined population spread through the rainwater tank network based on non-compliance rates of tanks (unsealed or sealed) and road grids. We show that Ae. aegypti tank infestation and population spread was greatest in areas of high tank density and road lengths were shortest e.g. cul-de-sacs. Rainwater tank non-compliance rates of over 30% show increased connectivity when compared to less than 10%, suggesting rainwater tanks non-compliance should be maintained under this level to minimize the spread of an invading Ae. aegypti population. These results presented as risk maps of Ae. aegypti spread across Brisbane, can assist health and government authorities on where to optimally target rainwater tank surveillance and educational activities., Supplementary Information: The online version contains supplementary material available at 10.1007/s10530-021-02619-z., Competing Interests: Conflict of interestThe authors have no relevant financial or non-financial interest to disclose., (© The Author(s), under exclusive licence to Springer Nature Switzerland AG 2021.) more...
- Published
- 2021
- Full Text
- View/download PDF
8. Temperature modulates immune gene expression in mosquitoes during arbovirus infection.
- Author
-
Wimalasiri-Yapa BMCR, Barrero RA, Stassen L, Hafner LM, McGraw EA, Pyke AT, Jansen CC, Suhrbier A, Yakob L, Hu W, Devine GJ, and Frentiu FD
- Subjects
- Aedes virology, Animals, Down-Regulation, Gene Ontology, Mosquito Vectors virology, RNA, Long Noncoding metabolism, Signal Transduction genetics, Temperature, Up-Regulation, Aedes metabolism, Chikungunya virus physiology, Immunity genetics, Mosquito Vectors immunology
- Abstract
The principal vector of dengue, Zika and chikungunya viruses is the mosquito Aedes aegypti , with its ability to transmit pathogens influenced by ambient temperature. We use chikungunya virus (CHIKV) to understand how the mosquito transcriptome responds to arbovirus infection at different ambient temperatures. We exposed CHIKV-infected mosquitoes to 18, 28 and 32°C, and found that higher temperature correlated with higher virus levels, particularly at 3 days post infection, but lower temperature resulted in reduced virus levels. RNAseq analysis indicated significantly altered gene expression levels in CHIKV infection. The highest number of significantly differentially expressed genes was observed at 28°C, with a more muted effect at the other temperatures. At the higher temperature, the expression of many classical immune genes, including Dicer-2 , was not substantially altered in response to CHIKV. The upregulation of Toll, IMD and JAK-STAT pathways was only observed at 28°C. Functional annotations suggested that genes in immune response and metabolic pathways related to energy supply and DNA replication were involved in temperature-dependent changes. Time post infection also led to substantially different gene expression profiles, and this varied with temperature. In conclusion, temperature significantly modulates mosquito gene expression in response to infection, potentially leading to impairment of immune defences at higher temperatures. more...
- Published
- 2021
- Full Text
- View/download PDF
9. Spatial and temporal patterns of Ross River virus in south east Queensland, Australia: identification of hot spots at the rural-urban interface.
- Author
-
Murphy AK, Clennon JA, Vazquez-Prokopec G, Jansen CC, Frentiu FD, Hafner LM, Hu W, and Devine GJ
- Subjects
- Adult, Alphavirus Infections transmission, Female, Humans, Incidence, Male, Middle Aged, Queensland epidemiology, Rural Health, Urban Health, Alphavirus Infections epidemiology, Ross River virus
- Abstract
Background: Ross River virus (RRV) is responsible for the most common vector-borne disease of humans reported in Australia. The virus circulates in enzootic cycles between multiple species of mosquitoes, wildlife reservoir hosts and humans. Public health concern about RRV is increasing due to rising incidence rates in Australian urban centres, along with increased circulation in Pacific Island countries. Australia experienced its largest recorded outbreak of 9544 cases in 2015, with the majority reported from south east Queensland (SEQ). This study examined potential links between disease patterns and transmission pathways of RRV., Methods: The spatial and temporal distribution of notified RRV cases, and associated epidemiological features in SEQ, were analysed for the period 2001-2016. This included fine-scale analysis of disease patterns across the suburbs of the capital city of Brisbane, and those of 8 adjacent Local Government Areas, and host spot analyses to identify locations with significantly high incidence., Results: The mean annual incidence rate for the region was 41/100,000 with a consistent seasonal peak in cases between February and May. The highest RRV incidence was in adults aged from 30 to 64 years (mean incidence rate: 59/100,000), and females had higher incidence rates than males (mean incidence rates: 44/100,000 and 34/100,000, respectively). Spatial patterns of disease were heterogeneous between years, and there was a wide distribution of disease across both urban and rural areas of SEQ. Overall, the highest incidence rates were reported from predominantly rural suburbs to the north of Brisbane City, with significant hot spots located in peri-urban suburbs where residential, agricultural and conserved natural land use types intersect., Conclusions: Although RRV is endemic across all of SEQ, transmission is most concentrated in areas where urban and peri-urban environments intersect. The drivers of RRV transmission across rural-urban landscapes should be prioritised for further investigation, including identification of specific vectors and hosts that mediate human spillover. more...
- Published
- 2020
- Full Text
- View/download PDF
10. Associations Between Ross River Virus Infection in Humans and Vector-Vertebrate Community Ecology in Brisbane, Australia.
- Author
-
Skinner EB, Murphy A, Jansen CC, Shivas MA, McCallum H, Onn MB, Reid SA, and Peel AJ
- Subjects
- Alphavirus Infections transmission, Animals, Biomass, Horses, Humans, Mosquito Vectors, Queensland epidemiology, Ross River virus isolation & purification, Alphavirus Infections epidemiology, Birds, Culicidae, Mammals
- Abstract
Transmission of vector-borne pathogens can vary in complexity from single-vector, single-host systems through to multivector, multihost vertebrate systems. Understanding the dynamics of transmission is important for disease prevention efforts, but is dependent on disentangling complex interactions within coupled natural systems. Ross River virus (RRV) is a multivector multihost pathogen responsible for the greatest number of notified vector-borne pathogen infections in humans in Australia. Current evidence suggests that nonhuman vertebrates are critical for the maintenance and spillover of RRV into mosquito populations. Yet, there is a limited knowledge of which mosquito vector species and amplifying vertebrate host species are most important for transmission of RRV to humans. We conducted field surveys of nonhuman vertebrates and mosquitoes in the RRV endemic city of Brisbane, Australia, to assess the effect of vector and host community structure on human RRV notifications. Six suburbs were selected across a gradient of human disease notification rates. Differences in vertebrate and mosquito compositions were observed across all suburbs. Suburbs with higher RRV notification rates contained greater vertebrate biomass (dominated by the presence of horses) and higher mosquito abundances. This study suggests that horse-mosquito interactions should be considered in more detail and that vertebrate biomass and mosquito abundance be incorporated into future RRV modeling studies and considered in public health strategies for RRV management. more...
- Published
- 2020
- Full Text
- View/download PDF
11. Estimation of mosquito-borne and sexual transmission of Zika virus in Australia: Risks to blood transfusion safety.
- Author
-
Viennet E, Frentiu FD, Williams CR, Mincham G, Jansen CC, Montgomery BL, Flower RLP, and Faddy HM
- Subjects
- Animals, Australia epidemiology, Communicable Diseases, Emerging epidemiology, Disease Outbreaks, Humans, Models, Biological, Public Health, Reproducibility of Results, Sexually Transmitted Diseases, Viral blood, Sexually Transmitted Diseases, Viral epidemiology, Zika Virus physiology, Zika Virus Infection epidemiology, Zika Virus Infection virology, Aedes virology, Blood Donors, Blood Safety standards, Mosquito Vectors virology, Sexually Transmitted Diseases, Viral transmission, Zika Virus Infection transmission
- Abstract
Background: Since 2015, Zika virus (ZIKV) outbreaks have occurred in the Americas and the Pacific involving mosquito-borne and sexual transmission. ZIKV has also emerged as a risk to global blood transfusion safety. Aedes aegypti, a mosquito well established in north and some parts of central and southern Queensland, Australia, transmits ZIKV. Aedes albopictus, another potential ZIKV vector, is a threat to mainland Australia. Since these conditions create the potential for local transmission in Australia and a possible uncertainty in the effectiveness of blood donor risk-mitigation programs, we investigated the possible impact of mosquito-borne and sexual transmission of ZIKV in Australia on local blood transfusion safety., Methodology/principal Findings: We estimated 'best-' and 'worst-' case scenarios of monthly reproduction number (R0) for both transmission pathways of ZIKV from 1996-2015 in 11 urban or regional population centres, by varying epidemiological and entomological estimates. We then estimated the attack rate and subsequent number of infectious people to quantify the ZIKV transfusion-transmission risk using the European Up-Front Risk Assessment Tool. For all scenarios and with both vector species R0 was lower than one for ZIKV transmission. However, a higher risk of a sustained outbreak was estimated for Cairns, Rockhampton, Thursday Island, and theoretically in Darwin during the warmest months of the year. The yearly estimation of the risk of transmitting ZIKV infection by blood transfusion remained low through the study period for all locations, with the highest potential risk estimated in Darwin., Conclusions/significance: Given the increasing demand for plasma products in Australia, the current strategy of restricting donors returning from infectious disease outbreak regions to source plasma collection provides a simple and effective risk management approach. However, if local transmission was suspected in the main urban centres of Australia, potentially facilitated by the geographic range expansion of Ae. aegypti or Ae. albopictus, this mitigation strategy would need urgent review., Competing Interests: The authors have declared that no competing interests exist. more...
- Published
- 2020
- Full Text
- View/download PDF
12. Urban Landscape Features Influence the Movement and Distribution of the Australian Container-Inhabiting Mosquito Vectors Aedes aegypti (Diptera: Culicidae) and Aedes notoscriptus (Diptera: Culicidae).
- Author
-
Trewin BJ, Pagendam DE, Zalucki MP, Darbro JM, Devine GJ, Jansen CC, and Schellhorn NA
- Subjects
- Animals, Cities, Female, Male, Mosquito Control, Queensland, Species Specificity, Aedes physiology, Animal Distribution, Environment, Mosquito Vectors physiology, Movement
- Abstract
Urban landscape features play an important role in the distribution and population spread of mosquito vectors. Furthermore, current insecticide and novel rear-and-release strategies for urban mosquito management rarely consider the spatial structure of the landscape when applying control practices. Here, we undertake a mark-recapture experiment to examine how urban features influence the movement and distribution of Australian container-inhabiting Aedes vectors. We pay attention to the role of semipermanent water storage containers, called rainwater tanks, and the influence of movement barriers, such as roads, on the spread and distribution of vector populations. Results suggest that Aedes aegypti (Linnaeus) (Diptera: Culicidae) were more likely to be captured around rainwater tanks, and that released males travel throughout residential blocks but do not cross roads. Conversely, female Aedes notoscriptus (Skuse) (Diptera: Culicidae) movement was uninhibited by roads and rainwater tanks did not influence female distribution or oviposition behavior. Using an isotropic Gaussian kernel framework, we show that vector movement is likely to be greater when applying a temporal effect, than when estimated by traditional methods. We conclude that a greater understanding on the role of urban features on vector movement will be important in the new age of rear-and-release mosquito control strategies, particularly those where estimations of movement are important for ensuring efficacy of application., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.) more...
- Published
- 2020
- Full Text
- View/download PDF
13. Epidemiologic, Entomologic, and Virologic Factors of the 2014-15 Ross River Virus Outbreak, Queensland, Australia.
- Author
-
Jansen CC, Shivas MA, May FJ, Pyke AT, Onn MB, Lodo K, Hall-Mendelin S, McMahon JL, Montgomery BL, Darbro JM, Doggett SL, and van den Hurk AF
- Subjects
- Alphavirus Infections history, Alphavirus Infections transmission, Disease Outbreaks, Genes, Viral, Geography, Medical, History, 21st Century, Humans, Mosquito Vectors virology, Phylogeny, Public Health Surveillance, Queensland epidemiology, Alphavirus Infections epidemiology, Alphavirus Infections virology, Ross River virus classification, Ross River virus genetics, Ross River virus immunology
- Abstract
Australia experienced its largest recorded outbreak of Ross River virus (RRV) during the 2014-15 reporting year, comprising >10,000 reported cases. We investigated epidemiologic, entomologic, and virologic factors that potentially contributed to the scale of the outbreak in Queensland, the state with the highest number of notifications (6,371). Spatial analysis of human cases showed that notifications were geographically widespread. In Brisbane, human case notifications and virus detections in mosquitoes occurred across inland and coastal locations. Viral sequence data demonstrated 2 RRV lineages (northeastern genotypes I and II) were circulating, and a new strain containing 3 unique amino acid changes in the envelope 2 protein was identified. Longitudinal mosquito collections demonstrated unusually high relative abundance of Culex annulirostris and Aedes procax mosquitoes, attributable to extensive freshwater larval habitats caused by early and persistent rainfall during the reporting year. Increased prevalence of these mosquitoes probably contributed to the scale of this outbreak. more...
- Published
- 2019
- Full Text
- View/download PDF
14. Chikungunya Virus Transmission at Low Temperature by Aedes albopictus Mosquitoes.
- Author
-
Wimalasiri-Yapa BMCR, Stassen L, Hu W, Yakob L, McGraw EA, Pyke AT, Jansen CC, Devine GJ, and Frentiu FD
- Abstract
Aedes albopictus is an important vector of chikungunya virus (CHIKV). In Australia, Ae. albopictus is currently only known to be present on the islands of the Torres Strait but, should it invade the mainland, it is projected to spread to temperate regions. The ability of Australian Ae. albopictus to transmit CHIKV at the lower temperatures typical of temperate areas has not been assessed. Ae. albopictus mosquitoes were orally challenged with a CHIKV strain from either Asian or East/Central/South African (ECSA) genotypes (10
7 pfu/mL), and maintained at a constant temperature of either 18 °C or 28 °C. At 3- and 7-days post-infection (dpi), CHIKV RNA copies were quantified in mosquito bodies, and wings and legs using real time polymerase chain reaction (qRT-PCR), while the detection of virus in saliva (a proxy for transmission) was performed by amplification in cell culture followed by observation of cytopathic effect in Vero cells. Of the ≥95% of Ae. albopictus that survived to 7 dpi, all mosquitoes became infected and showed body dissemination of CHIKV at both temperatures and time points. Both the Asian and ECSA CHIKV genotypes were potentially transmissible by Australian Ae. albopictus at 28 °C within 3 days of oral challenge. In contrast, at 18 °C none of the mosquitoes showed evidence of ability to transmit either genotype of CHIKV at 3 dpi. Further, at 18 °C only Ae. albopictus infected with the ECSA genotype showed evidence of virus in saliva at 7 dpi. Overall, infection with the ECSA CHIKV genotype produced higher virus loads in mosquitoes compared to infection with the Asian CHIKV genotype. Our results suggest that lower ambient temperatures may impede transmission of some CHIKV strains by Ae. albopictus at early time points post infection. more...- Published
- 2019
- Full Text
- View/download PDF
15. El Niño Southern Oscillation, overseas arrivals and imported chikungunya cases in Australia: A time series analysis.
- Author
-
Huang X, Hu W, Yakob L, Devine GJ, McGraw EA, Jansen CC, Faddy HM, and Frentiu FD
- Subjects
- Australia epidemiology, Humans, Seasons, Spatio-Temporal Analysis, Travel, Chikungunya Fever epidemiology, El Nino-Southern Oscillation
- Abstract
Background: Chikungunya virus (CHIKV) is an emerging mosquito-borne pathogen circulating in tropical and sub-tropical regions. Although autochthonous transmission has not been reported in Australia, there is a potential risk of local CHIKV outbreaks due to the presence of suitable vectors, global trade, frequent international travel and human adaptation to changes in climate., Methodology/principal Findings: A time series seasonal decomposition method was used to investigate the seasonality and trend of monthly imported CHIKV cases. This pattern was compared with the seasonality and trend of monthly overseas arrivals. A wavelet coherence analysis was applied to examine the transient relationships between monthly imported CHIKV cases and southern oscillation index (SOI) in time-frequency space. We found that the number and geographical distribution of countries of acquisition for CHIKV in travellers to Australia has increased in recent years. The number of monthly imported CHIKV cases displayed an unstable increased trend compared with a stable linear increased trend in monthly overseas arrivals. Both imported CHIKV cases and overseas arrivals showed substantial seasonality, with the strongest seasonal effects in each January, followed by each October and July. The wavelet coherence analysis identified four significant transient relationships between monthly imported CHIKV cases and 6-month lagged moving average SOI, in the years 2009-2010, 2012, 2014 and 2015-2016., Conclusion/significance: High seasonal peaks of imported CHIKV cases were consistent with the high seasonal peaks of overseas arrivals into Australia. Our analysis also indicates that El Niño Southern Oscillation (ENSO) variation may impact CHIKV epidemics in endemic regions, in turn influencing the pattern of imported cases., Competing Interests: The authors have declared that no competing interests exist. more...
- Published
- 2019
- Full Text
- View/download PDF
16. Life on the margin: Rainwater tanks facilitate overwintering of the dengue vector, Aedes aegypti, in a sub-tropical climate.
- Author
-
Trewin BJ, Darbro JM, Zalucki MP, Jansen CC, Schellhorn NA, and Devine GJ
- Subjects
- Aedes virology, Animals, Australia, Dengue virology, Dengue Virus, Larva virology, Mosquito Vectors virology, Rain, Seasons, Temperature, Tropical Climate, Water, Aedes physiology, Dengue transmission, Larva physiology, Mosquito Control methods, Mosquito Vectors physiology
- Abstract
A key determinant of insect persistence in marginal habitats is the ability to tolerate environmental extremes such as temperature. Aedes aegypti is highly invasive and little is known about the physiological sensitivity of the species to fluctuating temperature regimes at the lower critical threshold for development. A temperature that may limit the establishment and persistence of the species in sub-optimal regions. Daily winter temperatures were measured in common Australian larval habitats, replicated in environmental chambers and used to investigate the effect of fluctuating temperatures on the development and survival of tropical and subtropical strains of Australian Ae. aegypti. Development was slow for all treatments but both strains were able to complete development to the adult stage, suggesting previous models underestimate the potential for the species to persist in eastern Australia. Results suggested that thermal buffering in large volume habitats, and water that persists for greater than 32 days, will facilitate completion of the life cycle during sub-tropical winters. Furthermore, we provide a non-linear estimate of the lower critical temperature for Ae. aegypti development that suggests the current threshold may be incorrect. Our study demonstrates that the current re-introduction of water storage containers such as rainwater tanks, into major Australian population centres will increase the risk of Ae. aegypti establishment by permitting year-round development in locations south of its current distribution., Competing Interests: The authors have declared that no competing interests exist. more...
- Published
- 2019
- Full Text
- View/download PDF
17. Arboviral diseases and malaria in Australia, 2014–15: Annual report of the National Arbovirus and Malaria Advisory Committee
- Author
-
Knope K, Doggett SL, Jansen CC, Johansen CA, Kurucz N, Feldman R, Lynch SE, Hobby MP, Sly A, Jardine A, Bennett S, Currie BJ, and the National Arbovirus and Malaria Advisory Committee
- Abstract
This report describes the epidemiology of mosquito-borne diseases of public health importance in Australia during the 2014–15 season (1 July 2014 to 30 June 2015) and includes data from human notifications, sentinel chicken, vector and virus surveillance programs. The National Notifiable Diseases Surveillance System received notifications for 12,849 cases of disease transmitted by mosquitoes during the 2014–15 season. The Australasian alphaviruses Barmah Forest virus and Ross River virus accounted for 83% (n=10,723) of notifications. However, over-diagnosis and possible false positive diagnostic test results for these two infections mean that the true burden of infection is likely overestimated, and as a consequence, revised case definitions were implemented from 1 January 2016. There were 151 notifications of imported chikungunya virus infection. There were 74 notifications of dengue virus infection acquired in Australia and 1,592 cases acquired overseas, with an additional 34 cases for which the place of acquisition was unknown. Imported cases of dengue were most frequently acquired in Indonesia (66%). There were 7 notifications of Zika virus infection. No cases of locally-acquired malaria were notified during the 2014–15 season, though there were 259 notifications of overseas-acquired malaria and one notification for which no information on the place of acquisition was supplied. Imported cases of malaria were most frequently acquired in southern and eastern Africa (23%) and Pacific Island countries (20%). In 2014–15, arbovirus and mosquito surveillance programs were conducted in most of the states and territories. Surveillance for exotic mosquitoes at international ports of entry continues to be a vital part of preventing the establishment of vectors of mosquito-borne diseases such as dengue to new areas of Australia. In 2014-15, there was a sharp increase in the number of exotic mosquitoes detected at the Australian border, with 36 separate exotic mosquito detections made, representing a 280% increase from the 2013-14 period where there were 13 exotic mosquito detections., (© Commonwealth of Australia CC BY-NC-ND) more...
- Published
- 2019
- Full Text
- View/download PDF
18. Interpreting mosquito feeding patterns in Australia through an ecological lens: an analysis of blood meal studies.
- Author
-
Stephenson EB, Murphy AK, Jansen CC, Peel AJ, and McCallum H
- Subjects
- Animals, Australia, Blood, Humans, Mosquito Vectors physiology, Culicidae physiology, Feeding Behavior
- Abstract
Background: Mosquito-borne pathogens contribute significantly to the global burden of disease, infecting millions of people each year. Mosquito feeding is critical to the transmission dynamics of pathogens, and thus it is important to understanding and interpreting mosquito feeding patterns. In this paper we explore mosquito feeding patterns and their implications for disease ecology through a meta-analysis of published blood meal results collected across Australia from more than 12,000 blood meals from 22 species. To assess mosquito-vertebrate associations and identify mosquitoes on a spectrum of generalist or specialist feeders, we analysed blood meal data in two ways; first using a novel odds ratio analysis, and secondly by calculating Shannon's diversity scores., Results: We find that each mosquito species had a unique feeding association with different vertebrates, suggesting species-specific feeding patterns. Broadly, mosquito species could be grouped broadly into those that were primarily ornithophilic and those that fed more often on livestock. Aggregated feeding patterns observed across Australia were not explained by intrinsic variables such as mosquito genetics or larval habitats. We discuss the implications for disease transmission by vector mosquito species classified as generalist-feeders (such as Aedes vigilax and Culex annulirostris), or specialists (such as Aedes aegypti) in light of potential influences on mosquito host choice., Conclusions: Overall, we find that whilst existing blood meal studies in Australia are useful for investigating mosquito feeding patterns, standardisation of blood meal study methodologies and analyses, including the incorporation of vertebrate surveys, would improve predictions of the impact of vector-host interactions on disease ecology. Our analysis can also be used as a framework to explore mosquito-vertebrate associations, in which host availability data is unavailable, in other global systems. more...
- Published
- 2019
- Full Text
- View/download PDF
19. Epidemic potential of Zika virus in Australia: implications for blood transfusion safety.
- Author
-
Watson-Brown P, Viennet E, Mincham G, Williams CR, Jansen CC, Montgomery BL, Flower RLP, and Faddy HM
- Subjects
- Animals, Australia epidemiology, Female, Humans, Male, Aedes, Blood Safety, Blood Transfusion, Models, Biological, Mosquito Control, Mosquito Vectors, Zika Virus, Zika Virus Infection epidemiology, Zika Virus Infection prevention & control, Zika Virus Infection transmission
- Abstract
Background: Zika virus (ZIKV) is transfusion-transmissible. In Australia the primary vector, Aedes aegypti, is established in the north-east, such that local transmission is possible following importation of an index case, which has the potential to impact on blood transfusion safety and public health. We estimated the basic reproduction number (R
0 ) to model the epidemic potential of ZIKV in Australian locations, compared this with the ecologically similar dengue viruses (DENV), and examined possible implications for blood transfusion safety., Study Design and Methods: Varying estimates of vector control efficiency and extrinsic incubation period, "best-case" and "worst-case" scenarios of monthly R0 for ZIKV and DENV were modeled from 1996 to 2015 in 11 areas. We visualized the geographical distribution of blood donors in relation to areas with epidemic potential for ZIKV., Results: Epidemic potential (R0 > 1) existed for ZIKV and DENV throughout the study period in a number of locations in northern Australia (Cairns, Darwin, Rockhampton, Thursday Island, Townsville, and Brisbane) during the warmer months of the year. R0 for DENV was greater than ZIKV and was broadly consistent with annual estimates in Cairns. Increased vector control efficiency markedly reduced the epidemic potential and shortened the season of local transmission. Australian locations that provide the greatest number of blood donors did not have epidemic potential for ZIKV., Conclusion: We estimate that areas of north-eastern Australia could sustain local transmission of ZIKV. This early contribution to understanding the epidemic potential of ZIKV may assist in the assessment and management of threats to blood transfusion safety., (© 2019 AABB.) more...- Published
- 2019
- Full Text
- View/download PDF
20. Chikungunya virus in Asia - Pacific: a systematic review.
- Author
-
Wimalasiri-Yapa BMCR, Stassen L, Huang X, Hafner LM, Hu W, Devine GJ, Yakob L, Jansen CC, Faddy HM, Viennet E, and Frentiu FD
- Subjects
- Age Distribution, Asia, Southeastern epidemiology, Chikungunya Fever mortality, Chikungunya Fever virology, Chikungunya virus classification, Evidence-Based Medicine, Female, Genotype, Humans, Male, Phylogeography, Chikungunya Fever epidemiology, Chikungunya virus genetics
- Abstract
Chikungunya virus (CHIKV) is a mosquito-borne pathogen that causes an acute febrile syndrome and severe, debilitating rheumatic disorders in humans that may persist for months. CHIKV's presence in Asia dates from at least 1954, but its epidemiological profile in the region remains poorly understood. We systematically reviewed CHIKV emergence, epidemiology, clinical features, atypical manifestations and distribution of virus genotypes, in 47 countries from South East Asia (SEA) and the Western Pacific Region (WPR) during the period 1954-2017. Following the Cochrane Collaboration guidelines, Pubmed and Scopus databases, surveillance reports available in the World Health Organisation (WHO) and government websites were systematically reviewed. Of the 3504 records identified, 461 were retained for data extraction. Although CHIKV has been circulating in Asia almost continuously since the 1950s, it has significantly expanded its geographic reach in the region from 2005 onwards. Most reports identified in the review originated from India. Although all ages and both sexes can be affected, younger children and the elderly are more prone to severe and occasionally fatal forms of the disease, with child fatalities recorded since 1963 from India. The most frequent clinical features identified were arthralgia, rash, fever and headache. Both the Asian and East-Central-South African (ECSA) genotypes circulate in SEA and WPR, with ECSA genotype now predominant. Our findings indicate a substantial but poorly documented burden of CHIKV infection in the Asia-Pacific region. An evidence-based consensus on typical clinical features of chikungunya could aid in enhanced diagnosis and improved surveillance of the disease. more...
- Published
- 2019
- Full Text
- View/download PDF
21. The non-human reservoirs of Ross River virus: a systematic review of the evidence.
- Author
-
Stephenson EB, Peel AJ, Reid SA, Jansen CC, and McCallum H
- Subjects
- Alphavirus Infections transmission, Animals, Humans, Ross River virus classification, Ross River virus genetics, Ross River virus isolation & purification, Zoonoses transmission, Zoonoses virology, Alphavirus Infections veterinary, Alphavirus Infections virology, Disease Reservoirs virology, Ross River virus physiology
- Abstract
Understanding the non-human reservoirs of zoonotic pathogens is critical for effective disease control, but identifying the relative contributions of the various reservoirs of multi-host pathogens is challenging. For Ross River virus (RRV), knowledge of the transmission dynamics, in particular the role of non-human species, is important. In Australia, RRV accounts for the highest number of human mosquito-borne virus infections. The long held dogma that marsupials are better reservoirs than placental mammals, which are better reservoirs than birds, deserves critical review. We present a review of 50 years of evidence on non-human reservoirs of RRV, which includes experimental infection studies, virus isolation studies and serosurveys. We find that whilst marsupials are competent reservoirs of RRV, there is potential for placental mammals and birds to contribute to transmission dynamics. However, the role of these animals as reservoirs of RRV remains unclear due to fragmented evidence and sampling bias. Future investigations of RRV reservoirs should focus on quantifying complex transmission dynamics across environments. more...
- Published
- 2018
- Full Text
- View/download PDF
22. Discovery of new orbiviruses and totivirus from Anopheles mosquitoes in Eastern Australia.
- Author
-
Colmant AMG, Etebari K, Webb CE, Ritchie SA, Jansen CC, van den Hurk AF, Bielefeldt-Ohmann H, Hobson-Peters J, Asgari S, and Hall RA
- Subjects
- Animal Distribution, Animals, Australia, Cell Line, Orbivirus genetics, Phylogeny, Totivirus genetics, Anopheles virology, Orbivirus isolation & purification, Totivirus isolation & purification
- Abstract
Three new viruses classifiable within the Totivirus and Orbivirus genera were detected from Anopheles mosquito species collected in Eastern Australia. The viruses could not be isolated in C6/36 mosquito cell cultures but were shown to replicate in their mosquito hosts by small RNA analysis. The viruses grouped phylogenetically with other viruses recently detected in insects. These discoveries contribute to a better understanding of commensal viruses in Australian mosquitoes and the evolution of these viruses. more...
- Published
- 2017
- Full Text
- View/download PDF
23. Zika virus and Culex quinquefasciatus mosquitoes: a tenuous link.
- Author
-
van den Hurk AF, Hall-Mendelin S, Jansen CC, and Higgs S
- Subjects
- Animals, Humans, Zika Virus Infection virology, Culex virology, Mosquito Vectors virology, Zika Virus physiology, Zika Virus Infection transmission
- Published
- 2017
- Full Text
- View/download PDF
24. The elimination of the dengue vector, Aedes aegypti, from Brisbane, Australia: The role of surveillance, larval habitat removal and policy.
- Author
-
Trewin BJ, Darbro JM, Jansen CC, Schellhorn NA, Zalucki MP, Hurst TP, and Devine GJ
- Subjects
- Animals, Cities, Ecosystem, Health Policy, Humans, Queensland epidemiology, Aedes growth & development, Dengue prevention & control, Disease Transmission, Infectious prevention & control, Epidemiological Monitoring, Mosquito Control methods
- Abstract
Aedes aegypti (L.) (Diptera: Culicidae) is a highly invasive mosquito whose global distribution has fluctuated dramatically over the last 100 years. In Australia the distribution of Ae. aegypti once spanned the eastern seaboard, for 3,000 km north to south. However, during the 1900s this distribution markedly reduced and the mosquito disappeared from its southern range. Numerous hypotheses have been proffered for this retraction, however quantitative evidence of the mechanisms driving the disappearance are lacking. We examine historical records during the period when Ae. aegypti disappeared from Brisbane, the largest population centre in Queensland, Australia. In particular, we focus on the targeted management of Ae. aegypti by government authorities, that led to local elimination, something rarely observed in large cities. Numerous factors are likely to be responsible including the removal of larval habitat, especially domestic rainwater tanks, in combination with increased mosquito surveillance and regulatory enforcement. This account of historical events as they pertain to the elimination of Ae. aegypti from Brisbane, will inform assessments of the risks posed by recent human responses to climate change and the reintroduction of 300,000 rainwater tanks into the State over the past decade. more...
- Published
- 2017
- Full Text
- View/download PDF
25. Rapid Surveillance for Vector Presence (RSVP): Development of a novel system for detecting Aedes aegypti and Aedes albopictus.
- Author
-
Montgomery BL, Shivas MA, Hall-Mendelin S, Edwards J, Hamilton NA, Jansen CC, McMahon JL, Warrilow D, and van den Hurk AF
- Subjects
- Animals, Australia, Molecular Diagnostic Techniques methods, RNA, Ribosomal analysis, RNA, Ribosomal genetics, Reverse Transcriptase Polymerase Chain Reaction methods, Aedes growth & development, Entomology methods, Epidemiological Monitoring, Mosquito Vectors growth & development
- Abstract
Background: The globally important Zika, dengue and chikungunya viruses are primarily transmitted by the invasive mosquitoes, Aedes aegypti and Aedes albopictus. In Australia, there is an increasing risk that these species may invade highly urbanized regions and trigger outbreaks. We describe the development of a Rapid Surveillance for Vector Presence (RSVP) system to expedite presence- absence surveys for both species., Methodology/principal Findings: We developed a methodology that uses molecular assays to efficiently screen pooled ovitrap (egg trap) samples for traces of target species ribosomal RNA. Firstly, specific real-time reverse transcription-polymerase chain reaction (RT-PCR) assays were developed which detect a single Ae. aegypti or Ae. albopictus first instar larva in samples containing 4,999 and 999 non-target mosquitoes, respectively. ImageJ software was evaluated as an automated egg counting tool using ovitrap collections obtained from Brisbane, Australia. Qualitative assessment of ovistrips was required prior to automation because ImageJ did not differentiate between Aedes eggs and other objects or contaminants on 44.5% of ovistrips assessed, thus compromising the accuracy of egg counts. As a proof of concept, the RSVP was evaluated in Brisbane, Rockhampton and Goomeri, locations where Ae. aegypti is considered absent, present, and at the margin of its range, respectively. In Brisbane, Ae. aegypti was not detected in 25 pools formed from 477 ovitraps, comprising ≈ 54,300 eggs. In Rockhampton, Ae. aegypti was detected in 4/6 pools derived from 45 ovitraps, comprising ≈ 1,700 eggs. In Goomeri, Ae. aegypti was detected in 5/8 pools derived from 62 ovitraps, comprising ≈ 4,200 eggs., Conclusions/significance: RSVP can rapidly detect nucleic acids from low numbers of target species within large samples of endemic species aggregated from multiple ovitraps. This screening capability facilitates deployment of ovitrap configurations of varying spatial scales, from a single residential block to entire suburbs or towns. RSVP is a powerful tool for surveillance of invasive Aedes spp., validation of species eradication and quality assurance for vector control operations implemented during disease outbreaks. more...
- Published
- 2017
- Full Text
- View/download PDF
26. Epidemic Potential for Local Transmission of Zika Virus in 2015 and 2016 in Queensland, Australia.
- Author
-
Viennet E, Mincham G, Frentiu FD, Jansen CC, Montgomery BL, Harley D, Flower RL, Williams CR, and Faddy HM
- Abstract
Introduction: Zika virus could be transmitted in the state of Queensland, Australia, in parts of the state where the mosquito vectors are established., Methods: We assessed the epidemic potential of Zika in Queensland from January 2015 to August 2016, and estimate the epidemic potential from September to December 2016, by calculating the temperature-dependent relative vectorial capacity (rVc), based on empirical and estimated parameters., Results: Through 2015, we estimated a rVc of 0.119, 0.152, 0.170, and 0.175, respectively in the major cities of Brisbane, Rockhampton, Cairns, and Townsville. From January to August 2016, the epidemic potential trend was similar to 2015, however the highest epidemic potential was in Cairns. During September to November 2016, the epidemic potential is consistently the highest in Cairns, followed by Townsville, Rockhampton and Brisbane. Then, from November to December 2016, Townsville has the highest estimated epidemic potential., Discussion: We demonstrate using a vectorial capacity model that ZIKV could have been locally transmitted in Queensland, Australia during 2015 and 2016. ZIKV remains a threat to Australia for the upcoming summer, during the Brazilian Carnival season, when the abundance of vectors is relatively high. Understanding the epidemic potential of local ZIKV transmission will allow better management of threats to blood safety and assessment of public health risk. more...
- Published
- 2016
- Full Text
- View/download PDF
27. Risk Associated with the Release of Wolbachia-Infected Aedes aegypti Mosquitoes into the Environment in an Effort to Control Dengue.
- Author
-
Murray JV, Jansen CC, and De Barro P
- Abstract
Background: In an effort to eliminate dengue, a successful technology was developed with the stable introduction of the obligate intracellular bacteria Wolbachia pipientis into the mosquito Aedes aegypti to reduce its ability to transmit dengue fever due to life shortening and inhibition of viral replication effects. An analysis of risk was required before considering release of the modified mosquito into the environment., Methods: Expert knowledge and a risk assessment framework were used to identify risk associated with the release of the modified mosquito. Individual and group expert elicitation was performed to identify potential hazards. A Bayesian network (BN) was developed to capture the relationship between hazards and the likelihood of events occurring. Risk was calculated from the expert likelihood estimates populating the BN and the consequence estimates elicited from experts., Results: The risk model for "Don't Achieve Release" provided an estimated 46% likelihood that the release would not occur by a nominated time but generated an overall risk rating of very low. The ability to obtain compliance had the greatest influence on the likelihood of release occurring. The risk model for "Cause More Harm" provided a 12.5% likelihood that more harm would result from the release, but the overall risk was considered negligible. The efficacy of mosquito management had the most influence, with the perception that the threat of dengue fever had been eliminated, resulting in less household mosquito control, and was scored as the highest ranked individual hazard (albeit low risk)., Conclusions: The risk analysis was designed to incorporate the interacting complexity of hazards that may affect the release of the technology into the environment. The risk analysis was a small, but important, implementation phase in the success of this innovative research introducing a new technology to combat dengue transmission in the environment. more...
- Published
- 2016
- Full Text
- View/download PDF
28. A novel insect-specific flavivirus replicates only in Aedes-derived cells and persists at high prevalence in wild Aedes vigilax populations in Sydney, Australia.
- Author
-
McLean BJ, Hobson-Peters J, Webb CE, Watterson D, Prow NA, Nguyen HD, Hall-Mendelin S, Warrilow D, Johansen CA, Jansen CC, van den Hurk AF, Beebe NW, Schnettler E, Barnard RT, and Hall RA
- Subjects
- Aedes classification, Animals, Australia, Cell Line, Flavivirus classification, Flavivirus genetics, Flavivirus isolation & purification, Genome, Viral, Molecular Sequence Data, Phylogeny, Species Specificity, Aedes virology, Flavivirus physiology, Insect Vectors virology, Virus Replication
- Abstract
To date, insect-specific flaviviruses (ISFs) have only been isolated from mosquitoes and increasing evidence suggests that ISFs may affect the transmission of pathogenic flaviviruses. To investigate the diversity and prevalence of ISFs in Australian mosquitoes, samples from various regions were screened for flaviviruses by ELISA and RT-PCR. Thirty-eight pools of Aedes vigilax from Sydney in 2007 yielded isolates of a novel flavivirus, named Parramatta River virus (PaRV). Sequencing of the viral RNA genome revealed it was closely related to Hanko virus with 62.3% nucleotide identity over the open reading frame. PaRV failed to grow in vertebrate cells, with only Aedes-derived mosquito cell lines permissive to replication, suggesting a narrow host range. 2014 collections revealed that PaRV had persisted in A. vigilax populations in Sydney, with 88% of pools positive. Further investigations into its mode of transmission and potential to influence vector competence of A. vigilax for pathogenic viruses are warranted., (Copyright © 2015. Published by Elsevier Inc.) more...
- Published
- 2015
- Full Text
- View/download PDF
29. The Usual Suspects: Comparison of the Relative Roles of Potential Urban Chikungunya Virus Vectors in Australia.
- Author
-
Jansen CC, Williams CR, and van den Hurk AF
- Subjects
- Aedes classification, Animals, Australia epidemiology, Chikungunya Fever epidemiology, Chikungunya virus pathogenicity, Chikungunya virus physiology, Cities, Humans, Species Specificity, Aedes virology, Chikungunya Fever transmission, Insect Vectors, Models, Statistical
- Abstract
The global re-emergence of chikungunya virus (CHIKV) over the last decade presents a serious public health risk to Australia. An increasing number of imported cases further underline the potential for local transmission to occur if local mosquitoes bite an infected traveller. Laboratory experiments have identified a number of competent Australian mosquito species, including the primary vectors of CHIKV abroad, Aedes aegypti and Aedes albopictus, and local endemic species Aedes vigilax and Aedes notoscriptus. The implication of these additional endemic species as potential vectors has generated much uncertainty amongst public health professionals regarding their actual role in CHIKV transmission in the field. Using data estimated from or documented in the literature, we parameterise a simple vectorial capacity model to evaluate the relative roles of Australian mosquito species in potential CHIKV transmission. The model takes into account a number of key biological and ecological variables which influence the role of a species in field transmission, including population density, human feeding rates, mosquito survival rates and vector competence. We confirm the relative importance of Ae. aegypti and Ae. albopictus in sustaining potential CHIKV transmission in Australia. Even at maximum estimated densities and human feeding rates, Ae. vigilax and Ae. notoscriptus are likely to play a relatively minor role in CHIKV transmission, when compared with either Ae. aegypti or Ae. albopictus. This relatively straightforward analysis has application for any region where mosquito species have been incriminated in vector competence experiments, but where their actual role in CHIKV transmission has not been established. more...
- Published
- 2015
- Full Text
- View/download PDF
30. Field Comparison of Cyclopentanone Versus Carbon Dioxide as an Attractant for Adult Mosquitoes in Southeast Queensland, Australia.
- Author
-
Philippe-Janon JC, van den Hurk AF, Francis DP, Shivas MA, and Jansen CC
- Subjects
- Animals, Arboviruses physiology, Female, Queensland, Carbon Dioxide, Culicidae, Cyclopentanes, Insect Vectors, Mosquito Control methods, Sex Attractants
- Abstract
Cyclopentanone is a saturated monoketone typically used as an intermediate in the manufacture of pharmaceuticals, biologicals, insecticides, and rubber chemicals. Recently, it has been demonstrated that cyclopentanone activates the cpA CO2 receptor neuron on the maxillary palp of mosquitoes, suggesting that it may be a viable alternative to CO2 as an attractant for mosquitoes. Furthermore, semifield experiments showed that traps baited with cyclopentanone attract Culex quinquefasciatus Say at a similar rate to those baited with CO2. We evaluated the field efficacy of cyclopentanone as an alternative to CO2 in Centers for Disease Control (CDC) light traps and counterflow geometry (CFG) traps commonly used to collect mosquitoes in surveillance programs. Three pairwise trials and four Latin square trials were conducted across three peri-urban sites, comprising two saltwater sites and one freshwater site, in southeast Queensland, Australia. In all trials, CO2-baited traps outperformed traps baited with cyclopentanone. Carbon dioxide-baited CDC traps collected significantly more total mosquitoes, Aedes vigilax (Skuse), Culex sitiens Weidemann, and Culex annulirostris Skuse, than those baited with ≥99% cyclopentanone in pairwise trials. Similarly, in almost all Latin square trials, CO2-baited CDC and CFG traps collected significantly greater numbers of total mosquitoes, Ae. vigilax, Cx. annulirostris, Culex orbostiensis Dobrotworsky, and Cx. sitiens when compared with CFG traps baited with 20% cyclopentanone. Our trials indicate that cyclopentanone is not effective as a mosquito attractant in the field and cannot be used as a simple substitute for CO2 in commonly used mosquito surveillance traps., (© The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.) more...
- Published
- 2015
- Full Text
- View/download PDF
31. Arboviral diseases and malaria in Australia, 2011-12: annual report of the National Arbovirus and Malaria Advisory Committee.
- Author
-
Knope KE, Doggett SL, Kurucz N, Johansen CA, Nicholson J, Feldman R, Sly A, Hobby M, El Saadi D, Muller M, Jansen CC, and Muzari OM
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Alphavirus, Animals, Arbovirus Infections history, Arbovirus Infections transmission, Arbovirus Infections virology, Australia epidemiology, Child, Child, Preschool, Climate, Disease Notification, Disease Reservoirs, Disease Vectors, Female, Flavivirus, Geography, Medical, History, 21st Century, Humans, Infant, Infant, Newborn, Malaria history, Malaria prevention & control, Malaria transmission, Male, Middle Aged, Mosquito Control, Young Adult, Arbovirus Infections epidemiology, Malaria epidemiology, Population Surveillance
- Abstract
The National Notifiable Diseases Surveillance System received notifications for 7,875 cases of disease transmitted by mosquitoes during the 2011-12 season (1 July 2011 to 30 June 2012). The alphaviruses Barmah Forest virus and Ross River virus accounted for 6,036 (77%) of these. There were 18 notifications of dengue virus infection acquired in Australia and 1,390 cases that were acquired overseas, while for 38 cases, the place of acquisition was unknown. Imported cases of dengue in Australia were most frequently acquired in Indonesia. There were 20 imported cases of chikungunya virus. There were no notifications of locally-acquired malaria in Australia during the 2011-12 season. There were 314 notifications of overseas-acquired malaria and 41 notifications where the place of acquisition was unknown. Sentinel chicken, mosquito surveillance, viral detection in mosquitoes and climate modelling are used to provide early warning of arboviral disease activity in Australia. In 2011-12, sentinel chicken programs for the detection of flavivirus activity were conducted in most states with the risk of arboviral transmission. Other surveillance activities to detect the presence of arboviruses in mosquitoes or mosquito saliva or for surveying mosquito abundance included honey-baited trap surveillance, surveys of household containers that may provide suitable habitat for the dengue vector, Aedes aegypti, and carbon dioxide baited traps. Surveillance for exotic mosquitoes at the border continues to be a vital part of preventing the spread of mosquito-borne diseases to new areas of Australia., (This work is copyright. You may download, display, print and reproduce the whole or part of this work in unaltered form for your own personal use or, if you are part of an organisation, for internal use within your organisation, but only if you or your organisation do not use the reproduction for any commercial purpose and retain this copyright notice and all disclaimer notices as part of that reproduction. Apart from rights to use as permitted by the Copyright Act 1968 or allowed by this copyright notice, all other rights are reserved and you are not allowed to reproduce the whole or any part of this work in any way (electronic or otherwise) without first being given the specific written permission from the Commonwealth to do so. Requests and inquiries concerning reproduction and rights are to be sent to the Online, Services and External Relations Branch, Department of Health, GPO Box 9848, Canberra ACT 2601, or by email to copyright@health.gov.au.) more...
- Published
- 2014
32. Appropriate care for shelter-based abused women: concept mapping with Dutch clients and professionals.
- Author
-
Jonker IE, Jansen CC, Christians MG, and Wolf JR
- Subjects
- Attitude, Child, Child Welfare, Female, Humans, Male, Netherlands, Safety, Women's Rights, Battered Women, Health Services Needs and Demand, Housing, Social Work, Spouse Abuse
- Abstract
We conducted a concept mapping exercise to gain insight into the perspectives held by abused women and professionals with regard to appropriate care in Dutch women's shelters. Three brainstorming sessions generated 92 statements that were then rated by 56 clients and 51 professionals. A total of 11 clusters were identified. The three most important clusters were "help with finding a safe house if necessary," "safety and suitable care for the children," and "a personalized, respectful approach." The most important statement was "take women seriously and treat them with respect." The mapping exercise identified key practice-based elements of intervention that should better accommodate the needs of shelter-based abused women. We have used these elements in developing a new intervention for shelter-based abused women in the Netherlands. more...
- Published
- 2014
- Full Text
- View/download PDF
33. The role of Australian mosquito species in the transmission of endemic and exotic West Nile virus strains.
- Author
-
Jansen CC, Ritchie SA, and van den Hurk AF
- Subjects
- Animals, Australia epidemiology, Disease Outbreaks, Host-Pathogen Interactions, West Nile Fever virology, West Nile virus isolation & purification, Zoonoses, Culicidae virology, Insect Vectors virology, West Nile Fever epidemiology, West Nile Fever transmission, West Nile virus physiology
- Abstract
Recent epidemic activity and its introduction into the Western Hemisphere have drawn attention to West Nile virus (WNV) as an international public health problem. Of particular concern has been the ability for the virus to cause outbreaks of disease in highly populated urban centers. Incrimination of Australian mosquito species is an essential component in determining the receptivity of Australia to the introduction and/or establishment of an exotic strain of WNV and can guide potential management strategies. Based on vector competence experiments and ecological studies, we suggest candidate Australian mosquito species that would most likely be involved in urban transmission of WNV, along with consideration of the endemic WNV subtype, Kunjin. We then examine the interaction of entomological factors with virological and vertebrate host factors, as well as likely mode of introduction, which may influence the potential for exotic WNV to become established and be maintained in urban transmission cycles in Australia. more...
- Published
- 2013
- Full Text
- View/download PDF
34. Culex annulirostris (Diptera: Culicidae) host feeding patterns and Japanese encephalitis virus ecology in northern Australia.
- Author
-
Hall-Mendelin S, Jansen CC, Cheah WY, Montgomery BL, Hall RA, Ritchie SA, and Van den Hurk AF
- Subjects
- Animals, Cats, Cattle, Culex virology, Dogs, Encephalitis, Japanese transmission, Feeding Behavior, Humans, Insect Vectors virology, Northern Territory, Queensland, Culex physiology, Encephalitis Virus, Japanese, Host-Parasite Interactions, Insect Vectors physiology, Marsupialia parasitology, Swine parasitology
- Abstract
Japanese encephalitis virus (JEV) transmission in northern Australia has, in the past, been facilitated by Culex annulirostris Skuse feeding on domestic pigs, the primary amplifying hosts of the virus. To further characterize mosquito feeding behavior in northern Australia, 1,128 bloodmeals from Cx. annulirostris were analyzed using a double-antibody enzyme-linked immunosorbent assay. Overall, Cx. annulirostris obtained > 94% of blood meals from mammals, comprising marsupials (37%), pigs (20%), dogs (16%), and cows (11%), although the proportion feeding on each of these host types varied between study locations. Where JEV activity was detected, feeding rates on pigs were relatively high. At the location that yielded the first Australian mainland isolate of JEV from mosquitoes, feral pigs (in the absence of domestic pigs) accounted for 82% of bloodmeals identified, representing the first occasion that feeding on feral pigs has been associated with JEV transmission in Australia. Interestingly, < 3% of Cx. annulirostris had fed on pigs at locations on Badu Island where JEV was detected in multiple pools of mosquitoes in a concurrent study. This suggests that either alternative hosts, such as birds, which comprised 21% of blood meals identified, or infected mosquitoes immigrating from areas where domestic pigs are housed, may have contributed to transmission at this location. Because Cx. annulirostris is both an opportunistic feeder and the primary JEV vector in the region, environmental characteristics and host presence can determine JEV transmission dynamics in northern Australia. more...
- Published
- 2012
- Full Text
- View/download PDF
35. Surveillance study of hepatitis A virus RNA on fig and date samples.
- Author
-
Boxman IL, te Loeke NA, Klunder K, Hägele G, and Jansen CC
- Subjects
- Genotype, Hepatitis A virus genetics, Molecular Sequence Data, RNA, Viral genetics, Real-Time Polymerase Chain Reaction, Reverse Transcriptase Polymerase Chain Reaction, Sequence Analysis, DNA, Arecaceae virology, Ficus virology, Food Microbiology, Fruit virology, Hepatitis A virus isolation & purification, RNA, Viral isolation & purification
- Abstract
A total of 91 fig and 185 date samples were analyzed by reverse transcription (RT) real-time PCR for the presence of hepatitis A virus (HAV) RNA. Two batches of dates tested positive, and the HAV RNA detected was genotyped as IA. These findings warrant further development of methods applicable to food which is consumed untreated and is exported from countries in which HAV is endemic. more...
- Published
- 2012
- Full Text
- View/download PDF
36. Emerging tropical diseases in Australia. Part 5. Hendra virus.
- Author
-
Tulsiani SM, Graham GC, Moore PR, Jansen CC, Van Den Hurk AF, Moore FA, Simmons RJ, and Craig SB
- Subjects
- Animals, Australia epidemiology, Hendra Virus genetics, Hendra Virus isolation & purification, Henipavirus Infections mortality, Henipavirus Infections transmission, Horse Diseases epidemiology, Horse Diseases transmission, Horses, Humans, Immunohistochemistry, Nipah Virus pathogenicity, Zoonoses epidemiology, Zoonoses virology, Chiroptera virology, Disease Outbreaks statistics & numerical data, Hendra Virus pathogenicity, Henipavirus Infections epidemiology, Henipavirus Infections virology, Horse Diseases virology
- Abstract
Hendra virus (HeV) was first isolated in 1994, from a disease outbreak involving at least 21 horses and two humans in the Brisbane suburb of Hendra, Australia. The affected horses and humans all developed a severe but unidentified respiratory disease that resulted in the deaths of one of the human cases and the deaths or putting down of 14 of the horses. The virus, isolated by culture from a horse and the kidney of the fatal human case, was initially characterised as a new member of the genus Morbillivirus in the family Paramyxoviridae. Comparative sequence analysis of part of the matrix protein gene of the virus and the discovery that the virus had an exceptionally large genome subsequently led to HeV being assigned to a new genus, Henipavirus, along with Nipah virus (a newly emergent virus in pigs). The regular outbreaks of HeV-related disease that have occurred in Australia since 1994 have all been characterised by acute respiratory and neurological manifestations, with high levels of morbidity and mortality in the affected horses and humans. The modes of transmission of HeV remain largely unknown. Although fruit bats have been identified as natural hosts of the virus, direct bat-horse, bat-human or human-human transmission has not been reported. Human infection can occur via exposure to infectious urine, saliva or nasopharyngeal fluid from horses. The treatment options and efficacy are very limited and no vaccine exists. Reports on the outbreaks of HeV in Australia are collated in this review and the available data on the biology, transmission and detection of the pathogen are summarized and discussed. more...
- Published
- 2011
- Full Text
- View/download PDF
37. Emerging tropical diseases in Australia. Part 3. Australian bat lyssavirus.
- Author
-
Moore PR, Jansen CC, Graham GC, Smith IL, and Craig SB
- Subjects
- Animals, Australia epidemiology, Bites and Stings, Guidelines as Topic, Humans, Lyssavirus classification, Phylogeny, Post-Exposure Prophylaxis methods, Rhabdoviridae Infections transmission, Risk Factors, World Health Organization, Chiroptera virology, Lyssavirus isolation & purification, Rabies Vaccines administration & dosage, Rhabdoviridae Infections virology
- Abstract
Since its discovery in a juvenile black flying fox (Pteropus alecto) in 1996, Australian bat lyssavirus (ABLV) has become the cause of a potentially important emerging disease for health authorities in Australia, with two human deaths (one in 1996 and one in 1998) attributed to the virus in the north-eastern state of Queensland. In Australia, the virus has been isolated from all four species of flying fox found on the mainland (i.e. P. alecto, P. scapulatus, P. poliocephalus and P. conspicillatus) as well as a single species of insectivorous bat (Saccolaimus flaviventris). Australian bat lyssavirus belongs to the Lyssavirus genus and is closely related, genetically, to the type strain of Rabies virus (RABV). Clinically, patients infected with ABLV have displayed the 'classical' symptoms of rabies and a similar disease course. This similarity has led to the belief that the infection and dissemination of ABLV in the body follows the same pathways as those followed by RABV. Following the two ABLV-related deaths in Queensland, protocols based on the World Health Organization's guidelines for RABV prophylaxis were implemented and, presumably in consequence, no human infection with ABLV has been recorded since 1998. ABLV will, however, probably always have an important part to play in the health of Australians as the density of the human population in Australia and, consequently, the level of interaction between humans and flying foxes increase. more...
- Published
- 2010
- Full Text
- View/download PDF
38. Emerging tropical diseases in Australia. Part 4. Mosquitoborne diseases.
- Author
-
van den Hurk AF, Craig SB, Tulsiani SM, and Jansen CC
- Subjects
- Alphavirus isolation & purification, Alphavirus Infections epidemiology, Animals, Arbovirus Infections epidemiology, Arboviruses isolation & purification, Australia epidemiology, Disease Outbreaks, Humans, Public Health, Tropical Climate, Alphavirus Infections transmission, Arbovirus Infections transmission, Culicidae virology, Insect Vectors virology
- Abstract
Mosquito-borne diseases continue to be a serious public-health concern in Australia. Endemic alphaviruses (including Ross River and Barmah Forest viruses) account for the majority of the arboviral notifications, while some flaviviruses (Murray Valley encephalitis, Japanese encephalitis and Kunjin viruses) cause occasional outbreaks of encephalitis. Dengue epidemics are increasing in frequency in northern Queensland, with the largest outbreak in 50 years occurring during the 2008-2009 wet season. Of great concern are the threats posed by the importation of exotic arboviruses, such as West Nile, chikungunya and Rift Valley fever viruses, the introduction of exotic vectors, and the potential range expansion of key Australian vectors. Environmental and anthropogenic influences provide additional uncertainty regarding the future impact of mosquito-borne pathogens in Australia. This review discusses the trends, threats and challenges that face the management of mosquito-borne disease in Australia. Topical mosquito-borne pathogens of biosecurity and public-health concern, and the potential impacts of environmental and global trends, are discussed. Finally, a short overview of the public-health response capability in Australia is provided. more...
- Published
- 2010
- Full Text
- View/download PDF
39. Emerging tropical diseases in Australia. Part 1. Leptospirosis.
- Author
-
Tulsiani SM, Lau CL, Graham GC, Van Den Hurk AF, Jansen CC, Smythe LD, McKay DB, and Craig SB
- Subjects
- Anti-Bacterial Agents therapeutic use, Antibodies, Bacterial blood, Australia epidemiology, Biomarkers blood, Communicable Diseases, Emerging epidemiology, Communicable Diseases, Emerging prevention & control, Communicable Diseases, Emerging transmission, Enzyme-Linked Immunosorbent Assay, Humans, Leptospira immunology, Leptospirosis epidemiology, Leptospirosis prevention & control, Leptospirosis transmission, Polymerase Chain Reaction, Communicable Diseases, Emerging diagnosis, Leptospirosis diagnosis
- Abstract
Human leptospirosis is a zoonotic disease of global importance that causes significant morbidity and mortality, particularly in developing nations. In this review, the history, epidemiology, transmission, clinical presentation and treatment of this disease, and its impact in Australia, are discussed. Central to this review is the delineation of diagnostic methods for the disease and the challenges that this disease presents for both the clinician and diagnostic laboratory. This information should furnish clinicians with an updated tool to help overcome a number of problems associated with the diagnosis of leptospirosis. more...
- Published
- 2010
- Full Text
- View/download PDF
40. High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) for the characterisation of pathogenic leptospires: intra-serovar divergence, inter-serovar convergence, and evidence of attenuation in Leptospira reference collections.
- Author
-
Tulsiani SM, Craig SB, Graham GC, Cobbold RC, Dohnt MF, Burns MA, Jansen CC, Leung LK, Field HE, and Smythe LD
- Subjects
- Animals, Humans, Leptospira classification, Leptospira isolation & purification, Leptospirosis diagnosis, Leptospirosis microbiology, Mice, Rats, Transition Temperature, DNA Fingerprinting, DNA, Bacterial analysis, Leptospira genetics, Random Amplified Polymorphic DNA Technique methods
- Abstract
High-resolution melt-curve analysis of random amplified polymorphic DNA (RAPD-HRM) is a novel technology that has emerged as a possible method to characterise leptospires to serovar level. RAPD-HRM has recently been used to measure intra-serovar convergence between strains of the same serovar as well as inter-serovar divergence between strains of different serovars. The results indicate that intra-serovar heterogeneity and inter-serovar homogeneity may limit the application of RAPD-HRM in routine diagnostics. They also indicate that genetic attenuation of aged, high-passage-number isolates could undermine the use of RAPD-HRM or any other molecular technology. Such genetic attenuation may account for a general decrease seen in titres of rabbit hyperimmune antibodies over time. Before RAPD-HRM can be further advanced as a routine diagnostic tool, strains more representative of the wild-type serovars of a given region need to be identified. Further, RAPD-HRM analysis of reference strains indicates that the routine renewal of reference collections, with new isolates, may be needed to maintain the genetic integrity of the collections. more...
- Published
- 2010
- Full Text
- View/download PDF
41. The dengue vector Aedes aegypti: what comes next.
- Author
-
Jansen CC and Beebe NW
- Subjects
- Animals, Climate, Humans, Population Dynamics, Urban Population, Aedes growth & development, Aedes virology, Dengue transmission, Dengue Virus isolation & purification, Disease Vectors, Ecosystem
- Abstract
Aedes aegypti is the urban vector of dengue viruses worldwide. While climate influences the geographical distribution of this mosquito species, other factors also determine the suitability of the physical environment. Importantly, the close association of A. aegypti with humans and the domestic environment allows this species to persist in regions that may otherwise be unsuitable based on climatic factors alone. We highlight the need to incorporate the impact of the urban environment in attempts to model the potential distribution of A. aegypti and we briefly discuss the potential for future technology to aid management and control of this widespread vector species., (Copyright 2010 Elsevier Masson SAS. All rights reserved.) more...
- Published
- 2010
- Full Text
- View/download PDF
42. Hypomagnesaemia in the first 10 days of severe leptospirosis.
- Author
-
Craig SB, Graham GC, Burns MA, Dohnt MF, Jansen CC, Smythe LD, and McKay DB
- Subjects
- Adult, Aged, Female, Humans, Leptospirosis diagnosis, Magnesium Deficiency diagnosis, Male, Middle Aged, Retrospective Studies, Young Adult, Leptospirosis complications, Magnesium blood, Magnesium Deficiency etiology
- Abstract
Magnesium imbalance in leptospirosis has, for the most part, been neglected by the medical and leptospirosis communities. In a recent, retrospective study, serum concentrations of magnesium were followed in 15 patients with severe leptospirosis. The results revealed that 14 of the 15 patients developed hypomagnesaemia at some time during the first 10 days of their illness. In severely ill patients, such magnesium deficiency can worsen clinical outcome. Magnesium concentrations may affect a number of organ systems and mental status. Since altered mental status in leptospirosis is a poor prognostic indicator, it is suggested that serum concentrations of magnesium be monitored closely in patients with leptospirosis. Any hypomagnesaemia can then be treated promptly, in an effort to reduce the morbidity and mortality attributable to the disease. more...
- Published
- 2009
- Full Text
- View/download PDF
43. Blood sources of mosquitoes collected from urban and peri-urban environments in eastern Australia with species-specific molecular analysis of avian blood meals.
- Author
-
Jansen CC, Webb CE, Graham GC, Craig SB, Zborowski P, Ritchie SA, Russell RC, and van den Hurk AF
- Subjects
- Animals, Australia, Birds classification, Blood, Cities, Female, Humans, Mammals blood, Species Specificity, Birds blood, Culicidae classification, Culicidae physiology, Feeding Behavior physiology
- Abstract
To identify the hosts of mosquitoes collected from urban and peri-urban habitats in eastern Australia, 1,180 blood fed mosquitoes representing 15 species were analyzed by enzyme-linked immunosorbent assay and molecular techniques. Four common and epidemiologically important species could be classified according to their host-feeding patterns: Aedes aegypti was anthropophilic, Ae. vigilax was mammalophilic, Culex quinquefasciatus was ornithophilic, and Cx. annulirostris was opportunistic, readily feeding on birds and mammals. Mitochondrial cytochrome b DNA sequence data showed that more than 75% of avian blood meals identified from Cx. annulirostris collected from Brisbane, Newcastle, and Sydney originated from ducks (Order Anseriformes, Family Anatidae). More than 75% of avian blood meals from Cx. quinquefasciatus from Cairns belonged to one of three Passerine species, namely Sphecotheres vieilloti (figbird), Sturnus tristis (common myna), and Philemon buceroides (helmeted friarbird). This study demonstrates associations between vectors in Australia and vertebrate hosts of endemic and exotic arboviruses. more...
- Published
- 2009
- Full Text
- View/download PDF
44. Leptospirosis and Goodpasture's syndrome: testing the aetiological hypothesis.
- Author
-
Craig SB, Graham GC, Burns MA, Dohnt MF, Wilson RJ, Smythe LD, Jansen CC, and McKay DB
- Subjects
- Anti-Glomerular Basement Membrane Disease microbiology, Enzyme-Linked Immunosorbent Assay methods, Female, Glomerular Basement Membrane immunology, Humans, Leptospirosis diagnosis, Male, Risk Factors, Anti-Glomerular Basement Membrane Disease immunology, Autoantibodies blood, Immunoglobulins immunology, Leptospirosis immunology
- Abstract
Leptospiral pathogens have a world-wide distribution and cause a spectrum of disease ranging from a mild, influenza-like illness to Weil's disease, which manifests itself in multi-organ failure. Recently, Leptospira-reactive sera from 40 leptospirosis patients were investigated in an ELISA designed to detect antibodies to the human glomerular basement membrane (GBM). The aim was to determine if host-derived leptospiral immunoglobulins cross-react with proteins in the human GBM, so facilitating the development of Goodpasture's syndrome. As all 40 sera were found negative in the anti-GBM ELISA, the hypothesis that, during the immune phase of leptospirosis, patients are at risk of developing Goodpasture's syndrome was not supported. Further work is required to determine if leptospirosis is a risk factor in the development of any other pulmonary-renal syndromes that are associated with auto-immune diseases, such as Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome, Behçet's disease, IgA nephropathy and systemic lupus erythematosus. more...
- Published
- 2009
- Full Text
- View/download PDF
45. Arboviruses isolated from mosquitoes collected from urban and peri-urban areas of eastern Australia.
- Author
-
Jansen CC, Prow NA, Webb CE, Hall RA, Pyke AT, Harrower BJ, Pritchard IL, Zborowski P, Ritchie SA, Russell RC, and Van Den Hurk AF
- Subjects
- Animals, Australia, Cities, Culicidae classification, Demography, Ecosystem, Environmental Monitoring, Population Surveillance, Arboviruses classification, Arboviruses isolation & purification, Culicidae physiology, Culicidae virology
- Abstract
To determine the presence of arboviruses in mosquito populations from major urban areas of eastern Australia, a total of 67,825 mosquitoes, representing -60 species, was collected and tested from Cairns, Brisbane, and Sydney between January 2005 and April 2008. Mosquito pools were screened by inoculation onto mosquito cell cultures and the detection of viral antigen using a panel of flavivirus and alphavirus monoclonal antibodies in an enzyme-linked immunosorbent assay. Suspect positive samples were confirmed using virus-specific real-time reverse transcriptase-polymerase chain reaction assays. No flaviviruses were detected, but 2 alphaviruses were isolated from mosquito pools collected from Cairns, with 1 Barmah Forest virus isolate from a pool of 100 Aedes vigilax and 1 Ross River virus isolate from a pool of 83 Verrallina carmenti. In addition, a single Aedes alternans collected from Sydney yielded an isolate most similar to Stretch Lagoon virus, a newly described virus from the genus Orbivirus. These results suggest that during the study, arboviruses were circulating at a low level in the areas sampled. The findings from this study will promote public health awareness of the risk of arboviruses in urban areas, leading to more informative public health campaigns to safeguard the Australian public. more...
- Published
- 2009
- Full Text
- View/download PDF
46. Pepper chat fruit viroid: biological and molecular properties of a proposed new species of the genus Pospiviroid.
- Author
-
Verhoeven JT, Jansen CC, Roenhorst JW, Flores R, and de la Peña M
- Subjects
- Base Sequence, Cluster Analysis, Conserved Sequence, Solanum lycopersicum virology, Models, Molecular, Molecular Sequence Data, Netherlands, Phylogeny, Sequence Analysis, DNA, Sequence Homology, Nucleic Acid, Solanum tuberosum virology, Capsicum virology, Plant Diseases virology, Viroids genetics, Viroids isolation & purification
- Abstract
In autumn 2006, a new disease was observed in a glasshouse-grown crop of sweet pepper (Capsicum annuum L.) in the Netherlands. Fruit size of the infected plants was reduced up to 50%, and plant growth was also slightly reduced. Here we show that the disease is caused by a previously non-described viroid. The pepper viroid is transmitted by both mechanical inoculation and pepper seeds and, when inoculated experimentally, it infects several solanaceous plant species inducing vein necrosis and reduced fruit and tuber size in tomato and potato, respectively. The viroid RNA genome consists of 348 nucleotides and, with minor modifications, it has the central conserved and the terminal conserved regions characteristic of members of the genus Pospiviroid. Classification of the pepper viroid within the genus Pospiviroid is further supported by the presence and structure of hairpins I and II, the presence of internal and external RY motifs, and phylogenetic analyses. The primary structure of the pepper viroid only showed a maximum of 66% nucleotide sequence identity with other viroids, which is far below the main species demarcation limit of 90%. According to its biological and molecular properties, we propose to assign the pepper viroid to a new species within the genus Pospiviroid, and to name this new species Pepper chat fruit viroid. more...
- Published
- 2009
- Full Text
- View/download PDF
47. Transmission of Japanese Encephalitis virus from the black flying fox, Pteropus alecto, to Culex annulirostris mosquitoes, despite the absence of detectable viremia.
- Author
-
van den Hurk AF, Smith CS, Field HE, Smith IL, Northill JA, Taylor CT, Jansen CC, Smith GA, and Mackenzie JS
- Subjects
- Animals, Antibodies, Viral blood, Culex physiology, Female, Host-Pathogen Interactions, Immunoglobulin G blood, Insect Vectors physiology, Male, Viremia, Chiroptera virology, Culex virology, Encephalitis Virus, Japanese physiology, Encephalitis, Japanese transmission, Insect Vectors virology
- Abstract
To determine the potential role of flying foxes in transmission cycles of Japanese encephalitis virus (JEV) in Australia, we exposed Pteropus alecto (Megachiroptera: Pteropididae) to JEV via infected Culex annulirostris mosquitoes or inoculation. No flying foxes developed symptoms consistent with JEV infection. Anti-JEV IgG antibodies developed in 6/10 flying foxes exposed to infected Cx. annulirostris and in 5/5 inoculated flying foxes. Low-level viremia was detected by real-time reverse transcriptase polymerase chain reaction in 1/5 inoculated flying foxes and this animal was able to infect recipient mosquitoes. Although viremia was not detected in any of the 10 flying foxes that were exposed to JEV by mosquito bite, two animals infected recipient mosquitoes. Likewise, an inoculated flying fox without detectable viremia infected recipient mosquitoes. Although infection rates in recipient mosquitoes were low, the high population densities in roosting camps, coupled with migratory behavior indicate that flying foxes could play a role in the dispersal of JEV. more...
- Published
- 2009
48. Vector competence of Australian mosquito species for a North American strain of West Nile virus.
- Author
-
Jansen CC, Webb CE, Northill JA, Ritchie SA, Russell RC, and Van den Hurk AF
- Subjects
- Animals, Australia, North America, Culicidae virology, Insect Vectors virology, West Nile virus classification
- Abstract
Since the establishment of West Nile virus (WNV) into the United States, concern has arisen that this virus may also pose a serious threat to Australian biosecurity. The vector competence of 19 Australian mosquito species for a North American strain of WNV was evaluated. Mosquitoes collected from Cairns, Brisbane, and Sydney were exposed to blood containing 10(4.0+/-0.3) cell culture infectious dose(50)/mosquito WNV that was isolated from a crow during the 1999 New York outbreak. Mosquitoes were tested 12-15 days later to determine their infection, dissemination, and transmission rates. A number of Culex spp. demonstrated a high vector competence for this virus, with some populations of Culex annulirostris, the primary Australian Kunjin virus vector, displaying transmission rates up to 84%. Similarly, Cx. quinquefasciatus and Cx. gelidus were highly competent, with infection and transmission rates of >80% and >50%, respectively. Common Aedes spp., including Aedes notoscriptus, Ae. vigilax, and Ae. procax, were moderately susceptible, and some Verrallina spp. and Coquillettidia spp. were relatively refractory to infection. Thus, Australia possesses a number of competent mosquito species that could facilitate local transmission of WNV, should it be introduced. more...
- Published
- 2008
- Full Text
- View/download PDF
49. Expectoration of Flaviviruses during sugar feeding by mosquitoes (Diptera: Culicidae).
- Author
-
van den Hurk AF, Johnson PH, Hall-Mendelin S, Northill JA, Simmons RJ, Jansen CC, Frances SP, Smith GA, and Ritchie SA
- Subjects
- Animals, Female, Flaviviridae Infections transmission, RNA, Viral metabolism, Saliva virology, Sucrose metabolism, Culex virology, Feeding Behavior physiology, Flaviviridae isolation & purification
- Abstract
Biological transmission of arboviruses to a vertebrate host occurs when virions are expelled along with saliva during blood feeding by a hematophagous arthropod. We undertook experiments to determine whether mosquitoes expectorate flaviviruses in their saliva while sugar feeding. Batches of Culex annulirostris Skuse and Culex gelidus Theobald (Diptera: Culicidae) were orally infected with Japanese encephalitis (family Flaviviridae, genus Flavivirus, JEV), Kunjin (family Flaviviridae, genus Flavivirus, KUNV; a subtype of West Nile virus), and Murray Valley encephalitis (family Flaviviridae, genus Flavivirus, MVEV) viruses. After a 7-d extrinsic incubation, these mosquitoes were offered sucrose meals via cotton pledgets, which were removed daily and processed for viral RNA by using real-time TaqMan reverse transcriptase-polymerase chain reaction (RT-PCR) assays. JEV, MVEV, and KUNV RNA was detected in all pledgets removed from batches of Cx. gelidus on days 7-14 postexposure. In contrast, detection rates were variable for Cx. annulirostris, with KUNV detected in 0.3 M sucrose pledgets on all days postexposure, and JEV and MVEV detected on 57 and 50% of days postexposure, respectively. Higher concentrations of sucrose in the pledget did not increase virus detection rates. When individual JEV-infected Cx. gelidus were exposed to the sucrose pledget, 73% of mosquitoes expectorated virus with titers that were detectable by TaqMan RT-PCR. These results clearly show that flaviviruses are expectorated by infected mosquitoes during the process of sugar feeding on artificial pledgets. Potential applications of the method for arboviral bioassays and field surveillance are discussed. more...
- Published
- 2007
- Full Text
- View/download PDF
50. Prenatal diagnosis of the fragile X syndrome: loss of mutation owing to a double recombinant or gene conversion event at the FMR1 locus.
- Author
-
Losekoot M, Hoogendoorn E, Olmer R, Jansen CC, Oosterwijk JC, van den Ouweland AM, Halley DJ, Warren ST, Willemsen R, Oostra BA, and Bakker E
- Subjects
- Alleles, Blotting, Southern, Chromosome Mapping, Female, Fragile X Mental Retardation Protein, Fragile X Syndrome embryology, Fragile X Syndrome genetics, Gene Conversion, Genetic Markers, Humans, Male, Pedigree, Polymerase Chain Reaction, Prenatal Diagnosis, Chorionic Villi Sampling, Fragile X Syndrome diagnosis, Mutation, Nerve Tissue Proteins genetics, RNA-Binding Proteins, Recombination, Genetic
- Abstract
The fragile X syndrome, an X linked mental retardation syndrome, is caused by an expanded CGG repeat in the first exon of the FMR1 gene. In patients with an expanded repeat the FMR1 promoter is methylated and, consequently, the gene is silenced and no FMR1 protein (FMRP) is produced, thus leading to the clinical phenotype. Here we describe a prenatal diagnosis performed in a female from a fragile X family carrying a large premutation. In chorionic villus DNA of the male fetus the normal maternal CGG allele and a normal pattern on Southern blot analysis were found in combination with the FRAXAC2 and DXS297 allele of the maternal at risk haplotype. A second chorionic villus sampling was performed giving identical results on DNA analysis and, in addition, expression of FMRP was shown by immunohistochemistry. We concluded that the male fetus was not affected with the fragile X syndrome. Subsequent detailed haplotype analysis showed a complex recombination pattern resembling either gene conversion or a double crossover within a 20 kb genomic region. more...
- Published
- 1997
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.