Lyme disease in South Africa.

This article presents an overview of Lyme disease (LD) as it applies to neuropsychiatry and summarises research results on the epidemiology of LD in South Africa.

Unhealthy landscapes: policy recommendations on land use change and infectious disease emergence

Anthropogenic land use changes drive a range of infectious disease outbreaks and emergence events and modify the transmission of endemic infections. These drivers include agricultural encroachment, deforestation, road construction, dam building, irrigation, wetland modification, mining, the concentration or expansion of urban environments, coastal zone degradation, and other activities. These changes in turn cause a cascade of factors that exacerbate infectious disease emergence, such as forest fragmentation, disease introduction, pollution, poverty, and human migration. The Working Group on Land Use Change and Disease Emergence grew out of a special colloquium that convened international experts in infectious diseases, ecology, and environmental health to assess the current state of knowledge and to develop recommendations for addressing these environmental health challenges. The group established a systems model approach and priority lists of infectious diseases affected by ecologic degradation. Policy-relevant levels of the model include specific health risk factors, landscape or habitat change, and institutional (economic and behavioral) levels. The group recommended creating Centers of Excellence in Ecology and Health Research and Training, based at regional universities and/or research institutes with close links to the surrounding communities. The centers' objectives would be 3-fold: a) to provide information to local communities about the links between environmental change and public health ; b) to facilitate fully interdisciplinary research from a variety of natural, social, and health sciences and train professionals who can conduct interdisciplinary research ; and c) to engage in science-based communication and assessment for policy making toward sustainable health and ecosystems.

Reservoir-host amplification of disease impact in an endangered amphibian

Emerging wildlife pathogens are an increasing threat to biodiversity. One of the most serious wildlife diseases is chytridiomycosis, caused by the fungal pathogen, Batrachochytrium dendrobatidis (Bd), which has been documented in over 500 amphibian species. Amphibians vary greatly in their susceptibility to Bd, with some species tolerating infection, while others experience rapid mortality. Reservoir hosts - species that carry infection while maintaining high abundance, but are rarely killed by disease - can increase extinction risk in highly susceptible, sympatric species. However, whether reservoir hosts amplify Bd in declining amphibian species has not been examined. We combine a laboratory study with field surveys, disease sampling, and statistical modeling to investigate the role of reservoir hosts in chytridiomycosis dynamics and species decline in an amphibian community in south-eastern Australia. We show that the non-declining common eastern froglet (Crinia signifera) is a reservoir host for Bd, with laboratory animals carrying intense infection burdens over 12 weeks and the majority of wild sampled individuals carrying intense infections. We find that the presence of C. signifera is strongly associated with Bd prevalence in the sympatric, IUCN red-listed northern corroboree frog (Pseudophryne pengilleyi). Consistent with disease amplification by a reservoir host, we find that P. pengilleyi has declined from areas with high C. signifera abundance. Our results suggest that when reservoir hosts are present, population declines can continue long after the initial emergence of Bd, highlighting an urgent need to assess extinction risk in remnant populations of other declined amphibian species. Reintroductions and in situ management strategies must focus on identifying reservoir hosts and minimizing exposure of threatened species.