Search

Influenza A viruses (IAV) circulate endemically among many wild aquatic bird populations that seasonally migrate between wintering grounds in southern latitudes to breeding ranges along the perimeter of the circumpolar arctic. Arctic and subarctic zones are hypothesized to serve as ecologic drivers of the intercontinental movement and reassortment of IAVs due to high densities of disparate populations of long distance migratory and native bird species present during breeding seasons. Iceland is a staging ground that connects the East Atlantic and North Atlantic American flyways, providing a unique study system for characterizing viral flow between eastern and western hemispheres. Using Bayesian phylodynamic analyses, we sought to evaluate the viral connectivity of Iceland to proximal regions and how inter‐species transmission and reassortment dynamics in this region influence the geographic spread of low and highly pathogenic IAVs. Findings demonstrate that IAV movement in the arctic and subarctic reflects wild bird migration around the perimeter of the circumpolar north, favouring short‐distance flights between proximal regions rather than long distance flights over the polar interior. Iceland connects virus movement between mainland Europe and North America, consistent with the westward migration of wild birds from mainland Europe to Northeastern Canada and Greenland. Though virus diffusion rates were similar among avian taxonomic groups in Iceland, gulls play an outsized role as sinks of IAVs from other avian hosts prior to onward migration. These data identify patterns of virus movement in northern latitudes and inform future surveillance strategies related to seasonal and emergent IAVs with potential public health concern. [ABSTRACT FROM AUTHOR]

Suckling piglets play an important role at maintaining influenza A virus (IAV) infections in breeding herds and disseminating them to other farms at weaning. However, the role they play at weaning to support and promote genetic variability of IAV is not fully understood. The objective here was to evaluate the genetic diversity of IAV in pigs at weaning in farms located in the Midwestern USA. Nasal swabs (n = 9,090) collected from piglets in breed‐to‐wean farms (n = 52) over a six‐month period across seasons were evaluated for the presence of IAV. Nasal swabs (n = 391) from 23 IAV‐positive farms were whole‐genome sequenced. Multiple lineages of HA (n = 7) and NA (n = 3) were identified in 96% (22/23) and 61% (237/391) of the investigated farms and individual piglets, respectively. Co‐circulation of multiple types of functional HA and NA was identified in most (83%) farms. Whole IAV genomes were completed for 126 individual piglet samples and 25 distinct and 23 mixed genotypes were identified, highlighting significant genetic variability of IAV in piglets. Co‐circulation of IAV in the farms and co‐infection of individual piglets at weaning was observed at multiple time points over the investigation period and appears to be common in the investigated farms. Statistically significant genetic variability was estimated within and between farms by AMOVA, and varying levels of diversity between farms were detected using the Shannon–Weiner Index. Results reported here demonstrate previously unreported levels of molecular complexity and genetic variability among IAV at the farm and piglet levels at weaning. Movement of such piglets infected at weaning may result in emergence of new strains and maintenance of endemic IAV infection in the US swine herds. Results presented here highlight the need for developing and implementing novel, effective strategies to prevent or control the introduction and transmission of IAV within and between farms in the country. [ABSTRACT FROM AUTHOR]

There has been little surveillance of influenza A viruses (IAVs) circulating in swine at live animal markets, particularly in the United States. To address this gap, we conducted active surveillance of IAVs in pigs, the air, and the environment during a summer and winter season in a live animal market in St. Paul, Minnesota, that had been epidemiologically associated with swine‐origin influenza cases in humans previously. High rates of IAV were detected by PCR in swine lungs and oral fluids during both summer and winter seasons. Rates of IAV detection by PCR in the air were similar during summer and winter, although rates of successful virus isolation in the air were lower during summer than in winter (26% and 67%, respectively). H3N2 was the most prevalent subtype in both seasons, followed by H1N2. Genetically diverse viruses with multiple gene constellations were isolated from both winter and summer, with a total of 19 distinct genotypes identified. Comparative phylogenetic analysis of all eight segments of 40 virus isolates from summer and 122 isolates from winter revealed that the summer and winter isolates were genetically distinct, indicating IAVs are not maintained in the market, but rather are re‐introduced, likely from commercial swine. These findings highlight the extent of IAV genetic diversity circulating in swine in live animal markets, even during summer months, and the ongoing risk to humans. [ABSTRACT FROM AUTHOR]

Summary: Advances in whole‐genome sequencing (WGS) technologies have documented genetic diversity and epidemiology of the major foodborne pathogen Listeria monocytogenes (Lm) in Europe and North America, but data concerning South America are scarce. Here, we examined the population structure and genetic diversity of this major foodborne pathogen collected in Brazil. Based on core genome multilocus sequence typing (cgMLST), isolates from lineages I (n = 22; 63%) and II (n = 13; 37%) were distributed into 10 different sublineages (SLs) and represented 31 new cgMLST types (CTs). The most prevalent SLs were SL9 (n = 9; 26%), SL3 (n = 6; 17%) and SL2 and SL218 (n = 5; 14%). Isolates belonging to CTs L2‐SL9‐ST9‐CT4420 and L1‐SL315‐ST520‐CT4429 were collected 3 and 9 years apart, respectively, revealing long‐term persistence of Lm in Brazil. Genetic elements associated with stress survival were present in 60% of isolates (57% SSI‐1 and 3% SSI‐2). Pathogenic islands were present in 100% (LIPI‐1), 43% (LIPI‐3) and 6% (LIPI‐4) of the isolates. Mutations leading to premature stop codons were detected in the prfA and inlA virulence genes. This study is an important contribution to understanding the genomic diversity and epidemiology of Lm in South America. In addition, the results highlight the importance of using WGS to reveal Lm long‐term persistence. [ABSTRACT FROM AUTHOR]

Humans face a grand quality-of-life challenge as growing demands for resources for an ever-expanding population threaten the existence of wildlife populations, degrade land, and pollute air and water. Public investment and policy decisions that will shape future interactions of humans, animals, and the environment need scientific input to help find common ground for durable and sustainable success. The Second International Conference on One Medicine One Science brought together a broad range of scientists, trainees, regulatory authorities, and health experts from 34 countries to inform and discuss the human impacts of air quality; the complexities of water quality, access, and conflicts; the opportunities and uncertainties in precision medicine; and the role of science communication in health policy formulation. Workshops focused on the roles and development of physician-scientists and multidisciplinary teams in complex problem solving, Big Data tools for analysis and visualization, international policy development processes, and health models that benefit animals and humans. Key realizations were that local and regional health challenges at the interface of humans, animals, and the environment are variations of the same overarching conflicts and that international gatherings provide new opportunities for investigation and policy development that are broadly applicable. [ABSTRACT FROM AUTHOR]

The objective of this case-control study was to identify farm-level risk factors associated with bovine tuberculosis (bTB) in dairy cows in northern Thailand. Spatial analysis was performed to identify geographical clustering of case-farms located in Chiang Mai and Chiang Rai provinces in northern Thailand. To identify management factors affecting bTB status, a matched case-control study was conducted with 20 case-farms and 38 control-farms. Case-farms were dairy farms with at least single intradermal tuberculin test- (SIT-) reactor(s) in the farms during 2011 to 2015. Control-farms were dairy farms with no SIT-reactors in the same period and located within 5 km from case-farms. Questionnaires were administered for data collection with questions based on epidemiological plausibility and characteristics of the local livestock industry. Data were analyzed using multiple logistic regressions. A significant geographic cluster was identified only in Chiang Mai province (p<0.05). The risk factor associated with presence of SIT-reactors in dairy herds located in this region was purchasing dairy cows from dealers (OR = 5.85, 95% CI = 1.66–20.58, and p=0.006). From this study, it was concluded that geographic clustering was identified for dairy farms with SIT-reactors in these provinces, and the cattle movements through cattle dealers increased the risks for SIT-reactor farm status. [ABSTRACT FROM AUTHOR]

Characterizing the health consequences of interactions among animals, humans, and the environment in the face of climatic change, environmental disturbance, and expanding human populations is a critical global challenge in today's world. Exchange of interdisciplinary knowledge in basic and applied sciences and medicine that includes scientists, health professionals, key sponsors, and policy experts revealed that relevant case studies of monkeypox, influenza A, tuberculosis, and HIV can be used to guide strategies for anticipating and responding to new disease threats such as the Ebola and Chickungunya viruses, as well as to improve programs to control existing zoonotic diseases, including tuberculosis. The problem of safely feeding the world while preserving the environment and avoiding issues such as antibiotic resistance in animals and humans requires cooperative scientific problem solving. Food poisoning outbreaks resulting from Salmonella growing in vegetables have demonstrated the need for knowledge of pathogen evolution and adaptation in developing appropriate countermeasures for prevention and policy development. Similarly, pesticide use for efficient crop production must take into consideration bee population declines that threaten the availability of the two-thirds of human foods that are dependent on pollination. This report presents and weighs the objective merits of competing health priorities and identifies gaps in knowledge that threaten health security, to promote discussion of major public policy implications such that they may be decided with at least an underlying platform of facts. [ABSTRACT FROM AUTHOR]

Pathogen exchange between humans and primates has been facilitated by anthropogenic disturbances, such as changing land use patterns, habitat destruction, and poaching, which decrease population sizes and increase levels of primate-human interaction. As a result, human and domestic animal diseases have become a recognized threat to endangered primate populations. Tuberculosis is a major global human and animal health concern, especially in equatorial Africa where many of the remaining free-living great ape populations exist in proximity with exposed and/or infected human populations and their domestic animals. Increased anthropogenic pressure creates an opportunity for the anthropozoonotic spread of this disease. This review examines current evidence of the risk of tuberculosis transmission to great apes, the benefits and limitations of current detection methods, the impact of current great ape conservation and management strategies on this risk, and the need for an ecosystem health-based approach to mitigating the risks of tuberculosis transmission to great apes. Am. J. Primatol. 76:2-13, 2014. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background The genetic and antigenic characteristics of influenza A viruses ( IAV) within and between species change over time due to antigenic shift and drift. Although pigs are known to play a key role in the epidemiology of IAV between species, little is known about the molecular evolution of IAV hemagglutinin ( HA) in pigs. Objectives The aim of this study was to evaluate the HA drift of an H1 N1 IAV after infecting weaned pigs with or without maternally derived passive immunity. Methods Three- to four-week-old piglets born either to vaccinated or unvaccinated sows were contact-infected upon exposure with an IAV-infected pig. Nasal swabs were collected daily from each pig and tested for IAV by RRT-PCR. Full-length HA sequences were obtained directly from positive nasal swabs and compared between groups. Results Synonymous and non-synonymous mutations were detected in pigs with and without passive immunity. Most of the non-synonymous mutations occurred within the HA1 region of the HA. Changes within HA1 region were only identified in antigenic site B in pigs without passive immunity and in antigenic sites A, B, and D in pigs with passive immunity. However, there was no association between the immune status of the pig and the amino acid substitutions observed. Conclusions Overall, we demonstrated that amino acid substitutions within antigenic sites can happen in weaned pigs with or without passive immunity shortly after infection. [ABSTRACT FROM AUTHOR]

Please cite this paper as: Chander et al. (2012) Molecular and phylogenetic analysis of matrix gene of avian influenza viruses isolated from wild birds and live bird markets in the USA. Influenza and Other Respiratory Viruses 7(4), 513-520. Background Wild birds are the natural hosts for influenza A viruses (IAVs) and provide a niche for the maintenance of this virus. Objectives This study was undertaken to analyze nucleotide sequences of the matrix (M) gene of AIVs isolated from wild birds and live bird markets (LBMs) to index the changes occurring in this gene. Methods M-gene of 229 avian influenza virus (AIV) isolates obtained from wild birds and LBMs was amplified and sequenced. Full-length sequences (∼900 nt.) thus obtained were analyzed to identify changes that may be associated with resistance to adamantanes. Phylogenetic analysis of all sequences was performed using clustalw, and evolutionary distances were calculated by maximum composite likelihood method using mega ( ver. 5.0) software. Results Twenty-seven different viral subtypes were represented with H3N8 being the most dominant subtype in wild birds and H7N2 being the predominant subtype among isolates from LBMs. Phylogenetic analysis of the M-gene showed a high degree of nucleotide sequence identity with US isolates of AIVs but not with those of Asian or European lineages. While none of the isolates from wild birds had any antiviral resistance-associated mutations, 17 LBM isolates carried polymorphisms known to cause reduced susceptibility to antiviral drugs (adamantanes). Of these 17 isolates, 16 had S31N change and one isolate had V27A mutation. Conclusions These results indicate independent evolution of M-gene in the absence of any antiviral drugs leading to mutations causing resistance indicating the need for continued active surveillance of AIVs. [ABSTRACT FROM AUTHOR]

Mycobacterium tuberculosis and M. bovis share >99% genetic identity and induce similar host responses and disease profiles upon infection. There is a rich history of codiscovery in the development of control measures applicable to both human and bovine tuberculosis (TB) including skin-testing procedures, M. bovis BCG vaccination, and interferon-γ release assays. The calf TB infection model offers several opportunities to further our understanding of TB immunopathogenesis. Recent observations include correlation of central memory immune responses with TB vaccine efficacy, association of SIRPα+ cells in ESAT-6:CFP10- elicited multinucleate giant cell formation, early γδ T cell responses to TB, antimycobacterial activity of memory CD4+ T cells via granulysin production, association of specific antibody with antigen burden, and suppression of innate immune gene expression in infected animals. Partnerships teaming researchers with veterinary and medical perspectives will continue to provide mutual benefit to TB research in man and animals. [ABSTRACT FROM AUTHOR]

The article presents a study which assesses the effects of soil rainfall and tillage on the Cryptosporidium oocysts transport by no-till and tilled soils. It states that there is a high prevalence of Cryptosporidiosis due to the oocysts in manure and animal wastes in farmlands. It mentions that the study utilized twelve 30 by 30 by 30 centimeter blocks of Wooster silt loam soil gathered from the hay field at The Ohio Agricultural Research and Development Center's Wagner farm. The study treated six undisturbed till and no tilled soil blocks with a 1 liter liquid manure which contains 105 C. parvum oocysts in order to examine its effects on oocyst transport. Moreover, the study revealed that tillage manifest a greater effect on the Cryptosporidium oocysts transport by the soil.