Molecular epidemiology of gibbon hepatitis B virus transmission

Although transmission of human hepatitis B virus (HBV) variants to nonhuman primates is well documented, it remains to be elucidated whether nonhuman primate HBV is transmissible to humans. The prevalence and transmission routes of gibbon HBV were analysed in 101 captive gibbons in Thailand. Approximately 40 % of these animals showed at least one marker of HBV infection; 19 animals were chronic HBV carriers, characterized by elevated levels of alanine amino transferase and the presence of HBV DNA. Some of the chronic animals were found to be anti-HBc (HBV core antigen) negative (4 of 19), while precore promoter point mutations (nt 1762 or 1764) were determined in four animals by RFLP analysis. Phylogenetic tree analysis of the complete surface gene sequences revealed that gibbon viruses clustered separately from hepadnaviruses of other hosts. Evidence for horizontal and vertical transmission in captive gibbons was obtained. HBV DNA was also detected in the saliva of HBV carrier gibbons. Although some of the animal caretakers at the Krabok Koo Wildlife Breeding Centre were found to be chronic HBV carriers, genotype and sequence analysis did not reveal any evidence for zoonotic disease transmission

One Health drivers of antibacterial resistance: Quantifying the relative impacts of human, animal and environmental use and transmission

This is the final version. Available on open access from Elsevier via the DOI in this recordData accessibility statement: All model code is open source and available for download on GitHub https://github.com/rdbooton/OHDARTmodelObjectives Antibacterial resistance (ABR) is a major global health security threat, with a disproportionate burden on lower-and middle-income countries (LMICs). It is not understood how ‘One Health’, where human health is co-dependent on animal health and the environment, might impact the burden of ABR in LMICs. Thailand's 2017 “National Strategic Plan on Antimicrobial Resistance” (NSP-AMR) aims to reduce AMR morbidity by 50% through 20% reductions in human and 30% in animal antibacterial use (ABU). There is a need to understand the implications of such a plan within a One Health perspective. Methods A model of ABU, gut colonisation with extended-spectrum beta-lactamase (ESBL)-producing bacteria and transmission was calibrated using estimates of the prevalence of ESBL-producing bacteria in Thailand. This model was used to project the reduction in human ABR over 20 years (2020–2040) for each One Health driver, including individual transmission rates between humans, animals and the environment, and to estimate the long-term impact of the NSP-AMR intervention. Results The model predicts that human ABU was the most important factor in reducing the colonisation of humans with resistant bacteria (maximum 65.7–99.7% reduction). The NSP-AMR is projected to reduce human colonisation by 6.0–18.8%, with more ambitious targets (30% reductions in human ABU) increasing this to 8.5–24.9%. Conclusions Our model provides a simple framework to explain the mechanisms underpinning ABR, suggesting that future interventions targeting the simultaneous reduction of transmission and ABU would help to control ABR more effectively in Thailand.Antimicrobial Resistance Cross Council Initiativ

Comparison of outbreaks of H5N1 highly pathogenic AVIAN influenza in wild birds and poultry in thailand

Wild bird surveillance for highly pathogenic avian influenza (HPAI) H5N1 virus from 2004 to 2007 in Thailand indicated that the prevalence of infection with avian influenza H5N1 virus in wild birds was low (1.0%, 95% confidence interval [CI]: 0.7-1.2, 60/6, 263 pooled samples). However, the annual prevalence varied considerably over this period, with a peak of 2.7% (95% CI 1.4, 4.1) in 2004. Prevalence dropped to 0.5% (95% CI 0.3, 0.8]) and 0.6% (95% CI 0.3, 1.0) in 2005 and 2006, respectively, and then increased to 1.8% (95% CI 1.0, 2.6) in 2007. During this period, 16 species from 12 families of wild birds tested positive for H5N1 virus infection. All samples from juvenile birds were negative for H5N1 virus, whereas 0.6% (95% CI 0.4, 0.9) of pooled samples from adult birds were positive. Most positive samples originated from peridomestic resident species. Infected wild bird samples were only found in provinces where poultry outbreaks had occurred. Detection of H5N1 virus infection in wild birds was reported up to 3 yr after eradication of the poultry outbreaks in those provinces. As observed with outbreaks in poultry, the frequencies of H5N1 outbreaks in wild birds were significantly higher in winter. Further understanding of the mechanisms of persistence and ongoing HPAI H5N1 transmission between wild birds and domestic poultry is needed

Spatio-temporal patterns of leptospirosis in Thailand: is flooding a risk factor?

We studied the temporal and spatial patterns of leptospirosis, its association with flooding and animal census data in Thailand. Flood data from 2010 to 2012 were extracted from spatial information taken from satellite images. The incidence rate ratio (IRR) was used to determine the relationship between spatio-temporal flooding patterns and the number of human leptospirosis cases. In addition, the area of flood coverage, duration of waterlogging, time lags between flood events, and a number of potential animal reservoirs were considered in a sub-analysis. There was no significant temporal trend of leptospirosis over the study period. Statistical analysis showed an inconsistent relationship between IRR and flooding across years and regions. Spatially, leptospirosis occurred repeatedly and predominantly in northeastern Thailand. Our findings suggest that flooding is less influential in leptospirosis transmission than previously assumed. High incidence of the disease in the northeastern region is explained by the fact that agriculture and animal farming are important economic activities in this area. The periodic rise and fall of reported leptospirosis cases over time might be explained by seasonal exposure from rice farming activities performed during the rainy season when flood events often occur. We conclude that leptospirosis remains an occupational disease in Thailand. </p

A study of risk factors for infection with HPAI H5N1 in small poultry farms in Thailand using a questionnaire survey

A questionnaire was used to collect data on small poultry farm management and wild bird observed in poultry keeping areas to identify putative risk factors for infection with HPAI H5N1. The study was conducted in 2008 in four subdistricts of central Thailand that had experienced outbreaks of HPAI H5N1 in poultry. Descriptive and inferential analyses including univariable analyses and multivariable logistic regression were used to identify putative risk factors. Risk factors included purchasing native chickens/fighting cocks from commercial hatcheries, replacing or restocking birds individually, and observing lesser whistling ducks (Dendrocygna javanica) on the farm daily. Selecting healthy animals when purchasing animals to ensure that they were disease free was a protective factor. To fully understand the epidemiology of infection of small poultry farms with HPAI H5N1, control of movement of domestic poultry and serological and virological testing of the poultry population should be applied