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Eastern equine encephalitis virus (EEEV), Madariaga virus (MADV) and Venezuelan equine encephalitis virus complex (VEEV) are New World mosquito-borne alphaviruses and cause severe neurological disease in human and equine hosts. However, their detection during the acute phase is complicated by non-specific clinical manifestations and lack of available diagnostic tools. To develop and clinically evaluate rRT-PCRs for VEEV complex, MADV and EEEV, primers and probes were designed from publicly available whole-genome sequences. The rRT-PCRs were validated using 15 retrospective serum samples from febrile patients collected during the 2015 and 2017 alphavirus outbreaks in Panama. In addition, the protocol was validated with 150 mosquito pools from 2015, and with 118 samples from prospective disease surveillance from 2021 and 2022. The rRT-PCRs detected VEEV complex RNA in 10 samples (66.7%) from the 2015 and 2017 outbreaks, and in one of these ten samples, both VEEV complex and MADV RNAs were detected. Additionally, VEEV complex RNA was detected in 5 suspected dengue from prospective disease surveillance. The rRT-PCR assays detected VEEV complex RNA in 3 fromCulex(Melanoconion)vomeriferpools, 2 of which yielded VEEV isolates. Untargeted sequencing and phylogenetic analysis identified VEEV ID subtype in seven VEEV complex RNA positive sample. The VEEV complex, MADV and EEEV rRT-PCRs provide accurate detection while yielding significant benefits over currently available molecular methods. Our results suggest that 11.9% of suspected dengue cases in Panama are VEEV infections.

Altres ajuts: This research was supported by a grant from SENACYT FID 16-201 to J. P. C. and A. V., Secretar ́ıa Nacional de Ciencia y Tecnolog ́ıa from Panama; by the grant for neglected diseases studies in Panama 1.11.1.3.703.01.55.120 from the Ministry of Economy and Finance of Panama to J. P. C. and A. V.; and by ERANet17/HLH-0271. Scott Weaver also supported this study through the World Reference Center for Emerging Viruses and Arboviruses, NIH grant R24AI120942. Dr. Lescano is sponsored by the training grant D43 TW007393 awarded by the Fogarty International Center of the US National Institutes of Health. J. L. M. is a doctoral candidate studying an Epidemiological Research Doctorate at Universidad Peruana Cayetano Heredia under FONDECYT/CIENCIACTIVA scholarship EF033-235-2015 and also supported by training grant D43 TW007393. A. V. is a member of the Sistema Nacional de Investigación de Panamá (SNI), SENACYT. E. S. was supported by the Spanish Ministerio de Ciencia Innovaci ́on y Universidades (MICINN) through a Ramon y Cajal agreement (RYC-2016-21120). Alphaviruses (Togaviridae, Alphavirus) are arthropod-borne single-stranded RNA pathogens that cause febrile and neurologic disease in much of Latin America. However, many features of Alphavirus epidemiology remain unknown. In 2011, we undertook a cross-sectional study in Nueva Esperanza, an indigenous community in the Peruvian Amazon. Here, we present the first serologic evidence of Mayaro (MAYV), Venezuelan equine encephalitis (VEE) complex alphavirus, Una (UNAV), and Madariaga (MADV) viruses reported in humans (24%, 16%, 13%, and 1.5%, respectively) from an Amazonian indigenous community in Peru. Hunting activity and cohabiting with hunters were the main risk factors for Mayaro seroconversion, but only hunting was associated with UNAV seropositivity. Our results suggest that alphavirus infection in this region is common, but we highlight the high UNAV seroprevalence found and corroborate the low MADV prevalence reported in this region. Furthermore, MAYV-neutralizing antibodies were also detected in stored samples from wild animals (18%) hunted by Nueva Esperanza inhabitants and another mestizo community located close to Iquitos. Further serological surveys of VEE complex alphaviruses, UNAV, and MADV in wild animals and assessing the ability of the MAYV seropositive species to transmit the virus will be relevant.

Made available in DSpace on 2022-05-01T08:44:38Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Medical Research Council National Institutes of Health Paramyxoviruses have a broad host range and geographic distribution, including human pathogens transmitted by bats, such as Nipah and Hendra viruses. In this study, we combined high-throughput sequencing and molecular approaches to investigate the presence of paramyxoviruses in neotropical bats (Microchiroptera suborder) in Brazil. We discovered and characterized three novel paramyxoviruses in the kidney tissues of apparently healthy common vampire bats (D. rotundus) and Seba's short-tailed bats (C. perspicillata), which we tentatively named Kanhgág virus (KANV), Boe virus (BOEV), and Guató virus (GUATV). In this study, we classified these viruses as putative species into the Macrojêvirus genus, a newly proposed genus of the Orthoparamyxovirinae subfamily. Using RT-PCR, we detected these viruses in 20.9% (9 out of 43) of bats tested, and viral RNA was detected exclusively in kidney tissues. Attempts to isolate infectious virus were successful for KANV and GUATV. Our results expand the viral diversity, host range, and geographical distribution of the paramyxoviruses. World Reference Center for Emerging Viruses and Arboviruses and Department of Microbiology and Immunology University of Texas Medical Branch Virology Research Center Ribeirão Preto Medical School University of São Paulo, Ribeirão Preto Department of Zoology University of Oxford Department of Research in Virology and Biotechnology Gorgas Memorial Institute of Health Studies Institute of Biomedical Sciences University of São Paulo Evandro Chagas Institute, Ministry of Health Faculty of Veterinary Medicine São Paulo State University, Araçatuba Department of Infectious Disease Epidemiology Imperial College London MRC-University of Glasgow Centre for Virus Research Faculty of Veterinary Medicine São Paulo State University, Araçatuba FAPESP: 06/00572-0 FAPESP: 13/14929-1 FAPESP: 15/05778-5 FAPESP: 17/13981-0 FAPESP: 18/09383-3 FAPESP: 18/14389-0 FAPESP: 19/24251-9 Medical Research Council: MC_UU_12014/9 National Institutes of Health: R24 AI120942

BackgroundA new coronavirus SARS-CoV-2 was associated with a newly identified respiratory syndrome, COVID-19 in Wuhan, China, in early December 2019. SARS-CoV-2 rapidly spread across the globe resulting in 117 million cases and 2.59 million deaths by March 2021. Rapidly increased numbers of COVID-19 cases overwhelmed public health systems across the world, imposing increased working hours and workloads for health care workers. Here, we have evaluated the prevalence of health outcomes and associated factors of interns and resident physicians in Panama.MethodsA cross-sectional study was undertaken during July 23, 2020, to August 13, 2020, to evaluate the prevalence of health outcomes and associated factors in interns and residents across Panama. Snowball sampling was used to recruit participants. Then an electronic questionnaire with scales to evaluate anxiety disorders (GAD-7), depression (PHQ-9) and post-traumatic stress (IES-R) was evaluated. In addition, socio-demographic variables, clinical history of mental disorders and COVID-19 exposure were evaluated. Independent analyses for each mental health outcome were undertaken using a logistic regression analysis.ResultsA total of 517/1205 (42.9%) interns and residents were nationwide recruited. Of these 274 (53.0%) were interns and 243 (47.0%) residents. The overall prevalence of depression symptoms was 25.3%, 13.7% anxiety and 12.2% post-traumatic stress. At least, 9.3% participants reported having suicidal ideation.The most parsimonious model showed females had a higher prevalence of mental health disorders, in all results and the married participants were more likely to present depression (OR, 1.73; 95% CI, 1.03-2.91; P = 0.039) or at least one alteration to mental health (OR, 1.66; 95% CI, 1.03-2.68; P = 0.039). Resident physicians in surgical specialties were less likely to have post-traumatic stress (OR, 0.20; 95% CI, 0.06-0.63; P = 0.006) or at least one mental health disturbance (OR, 0.46; 95% CI, 0.26-0.83; P = 0.010). A history of psychological trauma and psychiatric pathology were risk factors for most of the disorders investigated.ConclusionsA high prevalence of mental health disorders was found, showing the need to mitigate this emotional burden among healthcare workers in the current context of the COVID-19 pandemic.

Madariaga virus (MADV) has recently been associated with severe human disease in Panama, where the closely related Venezuelan equine encephalitis virus (VEEV) also circulates. In June 2017, a fatal MADV infection was confirmed in a community of Darien Province. We conducted a cross-sectional outbreak investigation with human and mosquito collections in July 2017, where sera were tested for alphavirus antibodies and viral RNA. In addition, by applying a catalytic, force-of-infection (FOI) statistical model to two serosurveys from Darien Province in 2012 and 2017, we investigated whether endemic or epidemic alphavirus transmission occurred historically. In 2017, MADV and VEEV IgM seroprevalences were 1.6% and 4.4%, respectively; IgG antibody prevalences were MADV: 13.2%, VEEV: 16.8%, Una virus (UNAV): 16.0%, and Mayaro virus: 1.1%. Active viral circulation was not detected. Evidence of MADV and UNAV infection was found near households, raising questions about its vectors and enzootic transmission cycles. Insomnia was associated withMADVand VEEV infections, depression symptoms were associated with MADV, and dizziness with VEEV and UNAV. Force-of-infection analyses suggest endemic alphavirus transmission historically, with recent increased human exposure to MADV and VEEV in Aruza and Mercadeo, respectively. The lack of additional neurological cases suggests that severe MADV and VEEV infections occur only rarely. Our results indicate that over the past five decades, alphavirus infections have occurred at low levels in eastern Panama, but that MADV and VEEV infections have recently increased-potentially during the past decade. Endemic infections and outbreaks of MADV and VEEV appear to differ spatially in some locations of eastern Panama. National Institute for Health Research Revisión por pares

BackgroundHuman cases of Madariaga virus (MADV) infection were first detected during an outbreak in 2010 in eastern Panama, where Venezuelan equine encephalitis virus (VEEV) also circulates. Little is known about the long-term consequences of either alphavirus infection.MethodsA follow-up study of the 2010 outbreak was undertaken in 2015. An additional survey was carried out 2 weeks after a separate 2017 alphavirus outbreak in a neighboring population in eastern Panama. Serological studies and statistical analyses were undertaken in both populations.ResultsAmong the originally alphavirus-seronegative participants (n = 35 of 65), seroconversion was observed at a rate of 14.3% (95% CI, 4.8%–30.3%) for MADV and 8.6% (95% CI, 1.8%–23.1%) for VEEV over 5 years. Among the originally MADV-seropositive participants (n = 14 of 65), VEEV seroconversion occurred in 35.7% (95% CI, 12.8%–64.9%). In the VEEV-seropositive participants (n = 16 of 65), MADV seroconversion occurred in 6.3% (95% CI, 0.2%–30.2%). MADV seroreversion was observed in 14.3% (95% CI, 1.8%–42.8%) of those who were originally seropositive in 2010. VEEV seroconversion in the baseline MADV-seropositive participants was significantly higher than in alphavirus-negative participants. In the population sampled in 2017, MADV and VEEV seroprevalence was 13.2% and 16.8%, respectively. Memory loss, insomnia, irritability, and seizures were reported significantly more frequently in alphavirus-seropositive participants than in seronegative participants.ConclusionsHigh rates of seroconversion to MADV and VEEV over 5 years suggest frequent circulation of both viruses in Panama. Enhanced susceptibility to VEEV infection may be conferred by MADV infection. We provide evidence of persistent neurologic symptoms up to 5 years following MADV and VEEV exposure.

SummaryBackgroundWith more than 50000 accumulated cases, Panama has one of the highest incidences of SARS-CoV-2 in Central America, despite the fast implementation of disease control strategies. We investigated the early transmission patterns of the virus and the outcomes of mitigation measures in the country.MethodsWe collected information from epidemiological surveillance, including contact tracing, and genetic data from SARS-CoV-2 whole genomes, of the first five weeks of the outbreak. These data were used to estimate the exponential growth rate, doubling time and the time-varying effective reproductive number (Rt) using date of symptom onset in a Bayesian framework. The time of most recent ancestor for the introduced and circulating lineages was estimated by Bayesian analysis.FindingsA total of 4210 subjects were SARS-CoV-2 positive during the period evaluated, of them we sequenced 313 cases, detecting the circulation of 10 SARS-CoV-2 lineages. Whole genomes analysis identified the local transmission of one cryptic lineage as early as 2 weeks before it was detected by surveillance systems. Analysis of transmission dynamics showed that lockdown reduced Rt and increased the doubling time, however, these measures did not stop the circulation of this lineage in the country.InterpretationThese results demonstrate the value of epidemiological modeling and genome surveillance to assess mitigation strategies. At the same time, an active search for cryptic transmission clusters is crucial to interrupt local transmission of SARS-CoV-2 in a region.FundingMinistry of Health, Contribution from private donors and Secretaría Nacional de Ciencia y Tecnología.Research in ContextEvidence before this studyIn May 2020, we searched for published studies in PubMed and web of Science related to genetic variability and dynamics of SARS-CoV-2 transmission in Latin America, and there was none. On July 2020, there was one study of this type on SARS-CoV-2 transmission in Brazil and none in Central America. We were particularly interested in SARS-CoV-2 cryptic transmission that could allow the virus spread through locals without being detected by respiratory health system surveillance, and no publication was reported. On July 2020, seven papers (five in preprint) were about SARS-CoV-2 cryptic transmission, one in China, another in UK and five in the US. None in Central America. All of them showed the importance of genomic surveillance to detect different lineage introductions, cryptic transmission and its role in early spread in a region or in health-care setting.Added value of this studyWe integrate data collected from tested individual during national surveillance of COVID19 suspected cases or contact of cases, as part of the National COVID19 Laboratory network. This data was used to estimate epidemiological parameters of the outbreak as well as the effect of mitigation measures on the epidemic dynamic. We sequence the whole genome of SARS-COV-2 of 7.4% of RT-PCR confirmed cases at the national level, and with phylogenetic analysis we identified SARS-CoV-2 lineages introduced in the country and estimate date of their introductions. Epidemiological and genetic data was compared and we observed the cryptic transmission of one introduced lineage and the rise of a local lineage that was not detected by the active contact tracing implemented by the health system surveillance. This cryptic lineage could explain the fact that early implementation measures decreased the transmission rate and the increased the doubling time, however they were not able to eliminate totally the virus spread.Implications of all the available evidenceThis is the first study that analyzed the epidemiology and transmission dynamics of the early COVID19 epidemic in a Central American country using both epidemiological and genomic surveillance. Our findings suggest that strict containment measures and movement restrictions in Panama might have contributed to decrease the early spread of the virus, but that cryptic local transmission allowed a continual basal virus diffusion that could explain, in part, the high incidence of cases in the country. More broadly, our findings are crucial to inform intervention policy in real-time, for countries in similar situations and the importance of constant monitoring of SARS-CoV-2 lineages to understand its transmission in a region.

Background Chikungunya virus (CHIKV) emerged in the Americas in 2013 and has caused approximately 2.1 million cases and >600 deaths. A retrospective investigation was undertaken to describe clinical, epidemiological, and viral genomic features associated with deaths caused by CHIKV in Ceará state, northeast Brazil. Methods Sera, cerebrospinal fluid (CSF), and tissue samples from 100 fatal cases with suspected arbovirus infection were tested for CHIKV, dengue virus (DENV), and Zika virus (ZIKV). Clinical, epidemiological, and death reports were obtained for patients with confirmed CHIKV infection. Logistic regression analysis was undertaken to identify independent factors associated with risk of death during CHIKV infection. Phylogenetic analysis was conducted using whole genomes from a subset of cases. Results Sixty-eight fatal cases had CHIKV infection confirmed by reverse-transcription quantitative polymerase chain reaction (52.9%), viral antigen (41.1%), and/or specific immunoglobulin M (63.2%). Co-detection of CHIKV with DENV was found in 22% of fatal cases, ZIKV in 2.9%, and DENV and ZIKV in 1.5%. A total of 39 CHIKV deaths presented with neurological signs and symptoms, and CHIKV-RNA was found in the CSF of 92.3% of these patients. Fatal outcomes were associated with irreversible multiple organ dysfunction syndrome. Patients with diabetes appear to die at a higher frequency during the subacute phase. Genetic analysis showed circulation of 2 CHIKV East-Central-South African (ECSA) lineages in Ceará and revealed no unique virus genomic mutation associated with fatal outcome. Conclusions The investigation of the largest cross-sectional cohort of CHIKV deaths to date reveals that CHIKV-ECSA strains can cause death in individuals from both risk and nonrisk groups, including young adults., The introduction of the East-Central-South African genotype of Chikungunya virus (CHIKV) in Brazil caused neurological infections that led to death. The risk of death during acute and subacute CHIKV infection was higher in patients with diabetes.

The first case of COVID-19 was detected in Brazil on 25 February 2020. We report and contextualize epidemiological, demographic and clinical findings for COVID-19 cases during the first 3 months of the epidemic. By 31 May 2020, 514,200 COVID-19 cases, including 29,314 deaths, had been reported in 75.3% (4,196 of 5,570) of municipalities across all five administrative regions of Brazil. The R0 value for Brazil was estimated at 3.1 (95% Bayesian credible interval = 2.4–5.5), with a higher median but overlapping credible intervals compared with some other seriously affected countries. A positive association between higher per-capita income and COVID-19 diagnosis was identified. Furthermore, the severe acute respiratory infection cases with unknown aetiology were associated with lower per-capita income. Co-circulation of six respiratory viruses was detected but at very low levels. These findings provide a comprehensive description of the ongoing COVID-19 epidemic in Brazil and may help to guide subsequent measures to control virus transmission.

BackgroundHuman cases of Madariaga virus (MADV) infection were first detected during an outbreak in 2010 in eastern Panama, where Venezuelan equine encephalitis virus (VEEV) also circulates. Little is known about the long-term consequences of either alphavirus infection.MethodsA follow-up study of the 2010 outbreak was undertaken in 2015. An additional survey was carried out two weeks after a separate 2017 alphavirus outbreak in a neighboring population in eastern Panama. Serological studies and statistical analysis were undertaken in both populations.ResultsAmongst the originally alphavirus-seronegative subjects (n=35 of 65), seroconversion was observed at a rate of 14.3% (95% CI: 4.8%-30.3%) for MADV and 8.6% (95% CI: 1.8%-23.1%) for VEEV over 5 years. Amongst the originally MADV seropositive subjects (n=14 of 65), VEEV seroconversion occurred in 35.7% (95% CI: 12.8%-64.9%). In the VEEV seropositive subjects (n=16 of 65), MADV seroconversion occurred in 6.3% (95% CI: 0.2%-30.2%). MADV seroreversion was observed in 14.3% (95% CI: 1.8%-42.8%) of those originally seropositive in 2010. VEEV seroconversion in the baseline MADV-seropositive subjects was significantly higher than in alphavirus-negative subjects. In the population sampled in 2017, MADV and VEEV seroprevalence was 13.2% and 16.8%, respectively. Memory loss, insomnia, irritability and seizures were reported significantly more frequently in alphavirus-seropositive subjects than in seronegative.ConclusionsHigh rates of 5-year seroconversions to MADV and VEEV suggest continuous circulation of both viruses in Panama. Enhanced susceptibility may be conferred by MADV towards VEEV. We provide evidence of persistent neurologic symptoms up to 5 years following MADV and VEEV exposure.summaryWe estimate seroconversion rates over a 5-year period to Madariaga (MADV) and Venezuelan equine encephalitis (VEEV) alphaviruses in Panama. Individuals with MADV antibodies seroconverted to VEEV at a rate greater than individuals who were alphavirus-negative at baseline. This was not observed in individuals with VEEV antibodies, suggesting asymmetric cross-immunity. Neurological sequelae were reported more frequently by MADV and/or VEEV seropositive-versus seronegative subjects.

Determining effective sampling methods for mosquitoes are among the first objectives in elucidating transmission cycles of vector-borne zoonotic disease, as the effectiveness of sampling methods can differ based on species, location, and physiological state. The Spissipes section of the subgenus Melanoconion of Culex represents an understudied group of mosquitoes which transmit Venezuelan equine encephalitis viruses (VEEV) in the Western Hemisphere. The objective of this study was to determine effective collection methods that target both blood-engorged and non-engorged females of the Spissipes section of Culex subgenus Melanoconion to test the hypothesis that favorable trapping methods differ between species and by physiological status within a species. Mosquitoes were collected using two commercially available traps, (CDC-light trap and BG-Sentinel trap), two novel passive traps (a novel mosquito drift fence and pop-up resting shelters), and two novel aspirators, (a small-diameter aspirator and a large-diameter aspirator) in Darién, Panama, and Florida, USA. The total number of female mosquitoes collected for each species was compared using rarefaction curves and diversity metrics. We also compared the utility of each trap for collecting total females and blood-engorged females of four Spissipes section mosquito species in Florida and Darién. In Darién, it was found that both blood-engorged and unfed females of Cx. pedroi were most effectively collected using the mosquito drift fence at 57.6% and 61.7% respectively. In contrast, the most unfed Cx. spissipes were collected using the mosquito drift fence (40.7%) while blood-engorged females were collected effectively by pop-up resting shelters (42.3%). In Florida, the best sampling technique for the collection of blood-engorged Cx. panocossa was the large diameter aspirator at 41.9%, while the best trap for collecting Cx. cedecei was the pop-up resting shelter at 45.9%. For unfed female Spissipes section mosquitoes in Florida, the CDC light trap with CO2 collected 84.5% and 98.3% of Cx. cedecei and Cx. panocossa respectively in Florida. Rarefaction analysis, and both the Shannon and Simpsons diversity indices all demonstrated that the mosquito drift fence was capable of collecting the greatest diversity of mosquito species regardless of location. The finding that the proportions of unfed and blood-engorged mosquitoes collected by traps differed both among and between species has implications for how studies of VEEV vectors will be carried out in future investigations. In Florida a combination of pop-up resting shelters and use of a large-diameter aspirator would be optimal for the collection of both VEEV vectors for host-use studies. Results demonstrate that traps can be constructed from common materials to collect mosquitoes for VEEV vector studies and could be assessed for their utilization in vectors of other systems as well. Unfortunately, no single method was effective for capturing all species and physiological states, highlighting a particular need for assessing trap utility for target species of a study.

Members of the genera Alphavirus (family Togaviridae) and Flavivirus (family Flaviridae) are important zoonotic human and equine etiologic agents of neurologic diseases in the New World. In 2010, an outbreak of Madariaga virus (MADV; formerly eastern equine encephalitis virus) and Venezuelan equine encephalitis virus (VEEV) infections was reported in eastern Panamá. We further characterized the epidemiology of the outbreak by studying household contacts of confirmed human cases and of equine cases with neurological disease signs. Serum samples were screened using a hemagglutination inhibition test, and human results were confirmed using plaque reduction neutralization tests. A generalized linear model was used to evaluate the human MADV and VEEV seroprevalence ratios by age (in tercile) and gender. Overall, antibody prevalence for human MADV infection was 19.4%, VEEV 33.3%, and Mayaro virus 1.4%. In comparison with individuals aged 2-20 years, people from older age groups (21-41 and > 41 years) were five times more likely to have antibodies against VEEV, whereas the MADV prevalence ratio was independent of age. The overall seroprevalence of MADV in equids was 26.3%, VEEV 29.4%, West Nile virus (WNV) 2.6%, and St. Louis encephalitis virus (SLEV) was 63.0%. Taken together, our results suggest that multiple arboviruses are circulating in human and equine populations in Panamá. Our findings of a lack of increase in the seroprevalence ratio with age support the hypothesis of recent MADV exposure to people living in the affected region.

In this review, we attempt to give the reader an update on clinical diagnosis, management, and treatment of Chikungunya virus (CHIKV) infection regarding the course of the disease and the role of clinical laboratory. CHIKV infection evolves through three phases: acute, sub-acute, and chronic. Protocol for patient assessment and management should be in agreement with each phase requirements. Despite its benignity, CHIKV infection has shown an increase in severe cases during recent outbreaks. Among the most affected group are neonates, elderly population, and patients with co-morbidities. Furthermore, since CHIKV geographical distribution and clinical spectrum overlaps with other arboviruses, differential diagnosis becomes crucial for physicians to ensure good management and treatment for patients. In this review, we describe and compare the main symptoms, complications, and risk groups for CHIKV, Dengue (DENV), and Zika (ZIKV) infections, regarding key features will guide to an accurate diagnosis. CHIKV is an emergent and reemergent arbovirus that arrived in the Americas in 2014, causing thousands of infections. The acute febrile phase is similar to that of dengue but with a higher proportion of debilitating arthralgia that can persist for months or even years after infection. Severe forms of CHIKV infection can lead to chronic polyarthralgia, neurologic symptoms, or multiorgan failure. Treatment of CHIKV infection is mainly focused on supportive care, which includes the use of analgesic and anti-inflammatory medication, rehydration, and rest.

BackgroundMadariaga virus (MADV), has recently been associated with severe human disease in Panama, where the closely related Venezuelan equine encephalitis virus (VEEV) also circulates. In June, 2017, a fatal MADV infection was confirmed in a community of Darien province.MethodsWe conducted a cross-sectional outbreak investigation with human and mosquito collections in July 2017, where sera were tested for alphavirus antibodies and viral RNA. Additionally, by applying a catalytic, force-of-infection statistical model to two serosurveys from Darien province in 2012 and 2017, we investigated whether endemic or epidemic alphavirus transmission occurred historically.ResultsIn 2017, MADV and VEEV IgM seroprevalence was 1.6% and 4.4%, respectively; IgG antibody prevalences were MADV: 13.2%; VEEV: 16.8%; Una virus (UNAV): 16.0%; and Mayaro virus (MAYV): 1.1%. Active viral circulation was not detected. Evidence of MADV and UNAV infection was found near households — raising questions about its vectors and enzootic transmission cycles. Insomnia was associated with MADV and VEEV infection, depression symptoms were associated with MADV, and dizziness with VEEV and UNAV. Force-of-infection analyses suggest endemic alphavirus transmission historically, with recent increased human exposure to MADV and VEEV in some regions.ConclusionsThe lack of additional neurological cases suggest that severe MADV and VEEV infections occur only rarely. Our results indicate that, over the past five decades, alphavirus infections have occurred at low levels in eastern Panama, but that MADV and VEEV infections have recently increased — potentially during the past decade. Endemic infections and outbreaks of MADV and VEEV appear to differ spatially.Author summaryPrior to 2010, it was believed that the Madariaga virus (MADV) was primarily associated with equine disease. However, an outbreak reported in Panama, in an endemic area where Venezuelan equine encephalitis virus (VEEV) also circulates, suggested a change in its epidemiological profile. We aimed to reconstruct the epidemiological dynamics of MADV and VEEV, as well as additional alphaviruses known to circulate in the region in order to understand MADV emergence. For this, cross-sectional serosurveys were used to demonstrate that the Alphaviruses MADV, VEEV and Una virus have repeatedly infected humans in eastern Panama over the past five decades. Whilst their historical transmission has been low, we confirm that the transmission has recently increased for both MADV and VEEV.

Graphical Abstract This online structured survey has demonstrated the global impact of the COVID-19 pandemic on vascular services. The majority of centres have documented marked reductions in operating and services provided to vascular patients. In the months during recovery from the resource restrictions imposed during the pandemic peaks, there will be a significant vascular disease burden awaiting surgeons. Graphical Abstract One of the most affected specialties

Despite the importance of Aedes, Haemagogus and Sabethes in the transmission of yellow fever virus (YFV) and the public health impacts of recent YFV epidemics in the Americas, relatively little has been reported on the biology and ecology of these vectors. Many Aedes, Haemagogus and Sabethes spp. in the American tropics inhabit and develop in the forest canopy and are difficult to sample with conventional entomological surveillance methods. We tested the utility of two previously developed phytotelmata-style oviposition traps (bamboo Guadua angustifolia) and (monkey-pot Lecythis minor), for collecting immature forms of these mosquitoes in a forest near the community of Aruza Abajo, Darien Province, Panama. Our results showed distribution of mosquito species emerging from the two types of traps was found to be significantly different (X2 = 210.23; df = 14; P

Viruses in the genus Flavivirus (family Flaviviridae) include many arthropod-borne viruses of public health and veterinary importance. However, during the past two decades an explosion of novel insect-specific flaviviruses (ISFs), some closely related to vertebrate pathogens, have been discovered. Although many flavivirus pathogens of vertebrates have been isolated from naturally infected mosquitoes in Panama, ISFs have not previously been reported from the country. This report describes the isolation and characterization of a novel ISF, tentatively named Mercadeo virus (MECDV), obtained from Culex spp. mosquitoes collected in Panama. Two MECDV isolates were sequenced and cluster phylogenetically with cell-fusing agent virus (CFAV) and Nakiwogo virus (NAKV) to form a distinct lineage within the insect-specific group of flaviviruses.

The human bocavirus (HBoV) was added as a new member of the Parvoviridae family in 2005 upon its discovery in nasopharyngeal aspirates from children with respiratory infection. Recently, there has been increasing evidence of worldwide circulation of HBoV; however, in Latin America few studies have been conducted. In order to detect the circulation of HBoV in Panama, based on the National Flu Surveillance System, we developed this retrospective, cross-sectional study, from January 2011 to January 2012. Children younger than 6 years old who presented with respiratory disease were enrolled in this study. Nasopharyngeal swabs were taken in sentinel surveillance sites. Samples were tested to detect mRNA from HBoV, as well as viral RNA and DNA from others respiratory viruses. A total of 1078 patients were enrolled in this study. Overall, 44 (4.1%) of the patients presented HBoV. The most common symptoms were cough (84.6%), fever (82.1%), rhinorrhea (74.4%), and sore throat (38.5%). Less than half (45.5%) of HBoV infected patients presented with monoinfection while 54.5% of cases presented with coinfection with others respiratory viruses. Both, outpatients and inpatients were included in this study. Outpatients corresponded to 52.3% of the cases and 47.7% were inpatients. Coinfection was observed in the 50% of the inpatient cases. Phylogenetic analyses indicated that the circulating strains belonged to different clades of HBoV genotype 1. Taken together, our results support the pathogenic nature of this viral agent, especially in younger children.

Punta Toro virus (PTV), a member of the PTV complex, is a relatively common causative agent of febrile illness in Panama that is often misdiagnosed as 'dengue' or 'influenza'. Currently, only two named members make up this species complex, PTV and Buenaventura virus (BUEV). Genomic and antigenic characterization of 17 members of the PTV complex, nine of which were isolated from human acute febrile illness cases, reveals that this species complex is composed of six distant viruses. We propose to add four additional new viruses, designated Leticia virus, Cocle virus, Campana virus and Capira virus.

Chikungunya virus (CHIKV) is a mosquito-borne pathogen that was only endemic in Africa and south Asia until 2005 and 2006, when the virus spread into the Indian Ocean islands, Europe, and Asia. Autochthonous CHIKV transmission in the Caribbean islands was reported in December of 2013. In Panama, two febrile cases were detected in May of 2014: one traveling from Haiti, and the other traveling from the Dominican Republic. After other imported cases were detected, the first autochthonous case was reported in August of the same year. We detected CHIKV viral RNA and isolated the virus from serum samples. The phylogenetic analysis of the two imported isolates and one autochthonous CHIKV isolate indicated that the viruses belong to the Asian lineage in the Caribbean clade and are related to viruses recently identified in Saint Martin island, British Virgin Islands, China, and the Philippines. Although the circulating CHIKV lineages in the Americas have not yet been described, our results suggest that the Asian lineage is circulating in most American countries reporting autochthonous infection.

The Bunyaviridae family is made up of a diverse range of viruses, some of which cause disease and are a cause for concern in human and veterinary health. Here, we report the genomic and antigenic characterization of five previously uncharacterized bunyaviruses. Based on their ultrastructure, antigenic relationships and phylogenomic relationships, the five viruses are classified as members of the Orthobunyavirus genus. Three are viruses in the California encephalitis virus serogroup and are related to Trivittatus virus; the two others are most similar to the Mermet virus in the Simbu serogroup, and to the Tataguine virus, which is not currently assigned to a serogroup. Each of these five viruses was pathogenic to newborn mice, indicating their potential to cause illness in humans and other animals.

The circulation of the South-east Asian/American (AS/AM) dengue 2 virus (DENV-2) genotype in the Americas has been associated with a high rate of severe disease. From 1993, the year DENV was reintroduced in Panama, until 2011 there were 29 dengue-associated deaths, 17 of which occurred in 2011, the most severe outbreak with a case fatality rate (CFR) of 44% (17 deaths out of 38 severe dengue cases). During this outbreak DENV-2 was reintroduced into the country, whereas over the prior five years DENV-1 and -3 were predominant. Herein, we describe the 2011 Panama outbreak and genetically characterize the Panamanian DENV-2 strains, which were associated with severe dengue disease in Panama. Our results suggest that the DENV-2 isolates from this outbreak belonged to the AS/AM genotype sub-clade 2BI and were genetically close to viruses described in the outbreaks in Nicaragua, Honduras, Guatemala and Mexico from 2006-2011. Sub-clade 2BI has previously been associated with severe disease in Nicaragua during outbreaks from 2005-2007.

The identification of mosquito vector species present at arboviral enzootic transmission foci is important to understand transmission eco-epidemiology and to propose and implement prevention and control strategies that reduce vector-borne equine encephalitis transmis- sion. The goal of this study was to identify mosquito species potentially involved in the trans- mission of enzootic equine encephalitis, in relation to their abundance and diversity at three endemic regions in the Repu ́blica de Panama ́. We sampled adult mosquitoes during the dry and rainy season of Panama ́. We employed CDC light traps with octanol, EV traps with CO2 and Trinidad 17 traps baited with live hamsters. Traps were deployed in the peridomicile and extradomicile of houses from 18:00 to 6:00 h. We estimated the abundance and diver- sity of sampled species. We collected a total of 4868 mosquitoes, belonging to 45 species and 11 genera, over 216 sampling nights. Culex (Melanoconion) pedroi, a major Venezue- lan equine encephalitis vector was relatively rare (< 2.0% of all sampled mosquitoes). We also found Cx. (Mel) adamesi, Cx. (Mel) crybda, Cx. (Mel) ocossa, Cx. (Mel) spissipes, Cx. (Mel) taeniopus, Cx. (Mel) vomerifer, Aedes scapularis, Ae. angustivittatus, Coquillettidia venezuelensis, Cx. nigripalpus, Cx. declarator, Mansonia titillans, M. pseudotitillans and Psorophora ferox all species known to be vectorially competent for the transmission of arbo- viruses. Abundance and diversity of mosquitoes in the sampled locations was high, when compared with similar surveys in temperate areas. Information from previous reports about vectorial competence / capacity of the sampled mosquito species suggest that sampled locations have all the elements to support enzootic outbreaks of Venezuelan and Eastern equine encephalitides. La identificación de las especies de mosquitos vectores presentes en los focos de transmisión enzoótica de arbovirus es importante para entender la eco-epidemiología de la transmisión y para proponer y aplicar estrategias de prevención y control que reduzcan la transmisión de la encefalitis equina por vectores. El objetivo de este estudio fue identificar las especies de mosquitos potencialmente implicadas en la transmisión de la encefalitis equina enzoótica, en relación con su abundancia y diversidad en tres regiones endémicas de la República de Panamá ́. Se tomaron muestras de mosquitos adultos durante la época lluviosa de Panamá ́. Empleamos trampas de luz CDC con octanol, trampas EV con CO2 y trampas Trinidad 17 cebadas con hámsteres vivos. Las trampas se desplegaron en el peridomicilio y extradomicilio de las casas desde las 18:00 hasta las 6:00 h. Se estimó la abundancia y diversidad de las especies muestreadas. Recogimos un total de 4.868 mosquitos, pertenecientes a 45 especies y 11 géneros, durante 216 noches de muestreo. Culex (Melanoconion) pedroi, uno de los principales mosquitos de lancia de la encefalitis equina fue relativamente raro (< 2,0% de todos los mosquitos muestreados). En (Mel) adamesi, Cx. (Mel) crybda, Cx. (Mel) ocossa, Cx. (Mel) spissipes, Cx. (Mel) taeniopus, Cx. (Mel) vomerifer, Aedes scapularis, Ae. angustivittatus, Coquillettidia venezuelensis, Cx. nigripalpus, Cx. declarator, Mansonia titillans, M. pseudotitillans y Psorophora ferox, todas ellas especies conocidas por su competencia vectorial para la transmisión de arbovirus. La abundancia y la diversidad de los mosquitos en los lugares muestreados fue alta, cuando comparado con estudios similares en zonas templadas. La información de informes anteriores sobre las especies de mosquitos muestreadas sugieren que los lugares muestreados de las muestras sugieren que los lugares muestreados tienen todos los elementos para soportar brotes enzoóticos de encefalitis equina venezolana y oriental. Universidad Nacional, Costa Rica Escuela de Medicina Veterinaria

The eastern equine encephalitis (EEE) and Venezuelan equine encephalitis (VEE) viruses are pathogens that infect humans and horses in the Americas. Outbreaks of neurologic disease in humans and horses were reported in Panama from May through early August 2010.We performed antibody assays and tests to detect viral RNA and isolate the viruses in serum samples from hospitalized patients. Additional cases were identified with enhanced surveillance.A total of 19 patients were hospitalized for encephalitis. Among them, 7 had confirmed EEE, 3 had VEE, and 1 was infected with both viruses; 3 patients died, 1 of whom had confirmed VEE. The clinical findings for patients with EEE included brain lesions, seizures that evolved to status epilepticus, and neurologic sequelae. An additional 99 suspected or probable cases of alphavirus infection were detected during active surveillance. In total, 13 cases were confirmed as EEE, along with 11 cases of VEE and 1 case of dual infection. A total of 50 cases in horses were confirmed as EEE and 8 as VEE; mixed etiologic factors were associated with 11 cases in horses. Phylogenetic analyses of isolates from 2 cases of equine infection with the EEE virus and 1 case of human infection with the VEE virus indicated that the viruses were of enzootic lineages previously identified in Panama rather than new introductions.Cases of EEE in humans in Latin America may be the result of ecologic changes that increased human contact with enzootic transmission cycles, genetic changes in EEE viral strains that resulted in increased human virulence, or an altered host range. (Funded by the National Institutes of Health and the Secretaría Nacional de Ciencia, Tecnología e Innovación, Panama.).

Alphaviruses are enveloped, single-stranded, plus-strand RNA viruses belonging to the Togaviridae family. These are zoonotics and arthropod-borne viruses (mainly mosquitoes) that are distributed nearly worldwide. Many of the New World alphaviruses occur throughout Latin America: Venezuelan and eastern equine encephalitis viruses (VEEV, EEEV) in both North and South America, and western equine encephalitis virus (WEEV) from Canada to Argentina. Others such as Mayaro (MAYV), UNA (UNAV), and Aura (AURA) viruses have a more restricted distribution, and chikungunya virus (CHIKV) was recently introduced into Latin America. The evolutionary patterns show clades correlated with host/reservoirs (nonhuman primates, birds, and rodents) and distinctive human disease syndromes such as fever/rash/arthralgia and encephalomyelitis. The majority of alphaviruses cause at least mild febrile disease in humans and several produce severe, life-threatening diseases, whereas others are little studied epidemiologically and their public health importance is unknown. Recent studies in Latin America of “dengue-like” illness in several locations have revealed that many alphaviruses such as VEEV, EEEV, MAYV, and CHIKV are misdiagnosed as dengue; moreover, with the recent introduction of Zika virus, diagnosis based only on signs and symptoms is even more complicated in areas where these viruses are circulating simultaneously. This chapter describes important aspects of the alphaviruses in the region including evolution, outbreaks, vector–host, and eco-epidemiological/molecular determinants of their emergence from the New World viruses and chikungunya.

Background Neurotropic arboviral infections are an important cause of encephalitis. A zoonotic, vector-borne alphavirus, Madariaga virus (MADV; formerly known as South American eastern equine encephalitis virus), caused its first documented human outbreak in 2010 in Darien, Panama, where the genetically similar Venezuelan equine encephalitis virus (VEEV) is endemic. We report the results of a seroprevalence survey of animals and humans, illustrating contrasting features of MADV and VEEV ecology and epidemiology. Methods Small mammals were trapped in 42 sites in Darien, Panama, using Sherman traps, Tomahawk traps, and mist nets for bats. Blood was tested for the presence of neutralizing antibodies to MADV and VEEV. In addition, bird sera collected in 2007 in Chagres, Panama, were tested for MADV and VEEV neutralizing antibodies. Viremia was ascertained by RT-PCR. Human exposure to these two viruses was determined by IgG ELISA, followed by plaque reduction neutralization tests. To identify relevant risk factors for MADV or VEEV exposure, logistic regression analysis was performed, and the most parsimonious model was selected based on the Akaike information criterion. Results The animal survey yielded 32 bats (16 species), 556 rodents (12 species), and 20 opossums (4 species). The short-tailed cane mouse (Zygodontomys brevicauda) found abundantly in pasture and farms, had the highest MADV seroprevalence (8.3%). For VEEV, the shrub and forest-dwelling long-whiskered rice rat (Transandinomys bolivaris) had the highest seroprevalence (19.0%). Viremia was detected in one animal (Z. brevicauda). Of the 159 bird sera (50 species) tested, none were positive for either virus. In humans (n = 770), neutralizing antibodies to MADV and VEEV were present in 4.8% and 31.5%, respectively. MADV seropositivity was positively associated with cattle ranching, farming, and fishing. Having VEEV antibodies and shrubs near the house diminished risk. Age, forest work, farming and fishing were risk factors for VEEV, while having MADV antibodies, glazed windows, waste pick-up and piped water were protective. Conclusion Our findings suggest that the short-tailed cane mouse and the long-whiskered rice rat serve as hosts for MADV and VEEV, respectively. The preferred habitat of these rodent species coincides with areas associated with human infection risk. Our findings also indicate that MADV emerged recently in humans, and that the transmission cycles of these two sympatric alphaviruses differ spatially and in host utilization., Author Summary Arthropod-borne viruses are important causes of encephalitis. In 2010, the first documented human outbreak of the mosquito-borne, zoonotic Madariaga virus (MADV) occurred in the Darien region of Panama. Neither its epidemiology nor its transmission cycle is understood. In this study, the authors searched for possible animal hosts of this virus, and sought to describe its epidemiology. They contrast the findings with those for Venezuelan equine encephalitis virus (VEEV), an endemic, genetically similar virus. Zygodontomys brevicauda, the short-tailed cane mouse, had the highest seroprevalence for MADV. This rodent species is most often found in pasture and farm land. Indeed, the risk factors for human MADV exposure were cattle ranching and farming. The animal with highest seroprevalence for VEEV, the long-whiskered rice rat (Transandinomys bolivaris), commonly occurs in forest, and the epidemiological risk factors included working in the forest. Farming and fishing were risk factors for exposure to both viruses, and having antibodies to one virus diminished the risk of being positive for the other. Increasing prevalence with age was seen for VEEV, confirming that VEEV is endemic in the region. This association was absent for MADV, suggesting that this virus emerged recently to infect humans.

Background Chikungunya virus (CHIKV) typically causes explosive epidemics of fever, rash and polyarthralgia after its introduction into naïve populations. Since its introduction in Panama in May of 2014, few autochthonous cases have been reported; most of them were found within limited outbreaks in Panama City in 2014 and Puerto Obaldia town, near the Caribbean border with Colombia in 2015. In order to confirm that Panama had few CHIKV cases compared with neighboring countries, we perform an epidemiological analysis of chikungunya cases reported from May 2014 to July 2015. Moreover, to understand this paucity of confirmed CHIKV cases, a vectorial analysis in the counties where these cases were reported was performed. Methods Chikungunya cases were identified at medical centers and notified to health authorities. Sera samples were analyzed at Gorgas Memorial Institute for viral RNA and CHIKV-specific antibody detection. Results A total of 413 suspected cases of CHIKV infections were reported, with incidence rates of 0.5 and 0.7 per 100,000 inhabitants in 2014 and 2015, respectively. During this period, 38.6% of CHIKV cases were autochthonous with rash and polyarthralgia as predominant symptoms. CHIKV and DENV incidence ratios were 1:306 and 1:34, respectively. A phylogenetic analysis of E1/E2 genomic segment indicates that the outbreak strains belong to the Asian genotype and cluster together with CHIKV isolates from other American countries during the same period. Statistical analysis of the National Vector Control program at the district level shows low and medium vector infestation level for most of the counties with CHIKV cases. This index was lower than for neighboring countries. Conclusions Previous training of clinical, laboratory and vector workers allowed a good caption and detection of the chikungunya cases and fast intervention. It is possible that low/medium vector infestation level could explain in part the paucity of chikungunya infections in Panama., Author summary Chikungunya virus (CHIKV) is a mosquito borne pathogen that causes fever with rash and arthralgia, which are often confused with Dengue virus (DENV) infections. It has been reported that when CHIKV colonizes regions without previous circulation, it generally results in explosive human epidemics. In Panama, the first CHIKV infections were detected in May 2014. However, unlike many countries in the Americas, Panama presented with few autochthonous cases during the outbreak. In this study, we investigated the likely reason for the paucity of cases. Low vector infestation level, along with the surveillance programs, preparedness and early outbreak response possibly influenced the low number of cases observed during the Panamanian CHIKV outbreak.

The human bocavirus (HBoV) was added as a new member of the Parvoviridae family in 2005 upon its discovery in nasopharyngeal aspirates from children with respiratory infection. Recently, there has been increasing evidence of worldwide circulation of HBoV; however, in Latin America few studies have been conducted. In order to detect the circulation of HBoV in Panama, based on the National Flu Surveillance System, we developed this retrospective, cross-sectional study, from January 2011 to January 2012. Children younger than 6 years old who presented with respiratory disease were enrolled in this study. Nasopharyngeal swabs were taken in sentinel surveillance sites. Samples were tested to detect mRNA from HBoV, as well as viral RNA and DNA from others respiratory viruses. A total of 1078 patients were enrolled in this study. Overall, 44 (4.1%) of the patients presented HBoV. The most common symptoms were cough (84.6%), fever (82.1%), rhinorrhea (74.4%), and sore throat (38.5%). Less than half (45.5%) of HBoV infected patients presented with monoinfection while 54.5% of cases presented with coinfection with others respiratory viruses. Both, outpatients and inpatients were included in this study. Outpatients corresponded to 52.3% of the cases and 47.7% were inpatients. Coinfection was observed in the 50% of the inpatient cases. Phylogenetic analyses indicated that the circulating strains belonged to different clades of HBoV genotype 1. Taken together, our results support the pathogenic nature of this viral agent, especially in younger children.

We present the first report of a pediatric case of acute disseminated encephalomyelitis (ADEM) associated with Madariaga virus infection (MADV, Alphavirus, Togaviridae; formerly known as South American variants of eastern equine encephalitis virus [EEEV]) in a patient of the 2010 alphaviral epidemic reported in Panama. The patient was admitted to the Hospital del Nino in Panama City with suspected meningitis, exhibited with decreased alertness and disorientation in space and time, hemiparesis, and left Babinski sign. The patient was transferred to the intensive care unit and treated with aciclovir and methylprednisolone. The magnetic resonance imaging (MRI) of the brain revealed multiple hyperintense lesions at T2-weighted images (T2) and fluid-attenuated inversion recovery (FLAIR) on the cortical–subcortical level. Sera samples obtained on days 6 and 12 were immunoglobulin M (IgM) positive for MADV. The findings on the clinical and cerebrospinal analyses, rapid symptom progression as well as neuroimaging, and serologic studies support our diagnosis. Our results suggest that MADV should be included in the etiologic differential diagnosis of ADEM in endemic countries.