Is gibbon ape leukaemia virus still a threat?

In the late 1960s and early 1970s, an outbreak of lymphoma and leukaemia in gibbons (Hylobatidae), attributed to the retrovirus gibbon ape leukaemia virus (GALV), was widely reported in the literature. The virus was identified in captive gibbon colonies in Thailand, the USA and Bermuda.The virus is a known cell culture contaminant and, in particular, research into HIV can be impeded by expression of GALV particles in HIV permissive cell lines.In this review, we bring together published work, laboratory records from early GALV research, correspondence about the transportation of gibbons during the 1960s and 1970s, phylogenetic analyses, laboratory screening and zoological records for the first time, to discover more about the origin and transmission of GALV. Based on this evidence, we suggest that GALV may have been transmitted to gibbons as an iatrogenic event and was never widespread. Instead, all infected gibbons were probably transported from the site of the original outbreak, housed with gibbons from this site or infected with material derived from gibbons from this site. We also propose that GALV is not an ongoing pathogen of captive gibbons

Using shared needles for subcutaneous inoculation can transmit bluetongue virus mechanically between ruminant hosts

Bluetongue virus (BTV) is an economically important arbovirus of ruminants that is transmitted by Culicoides spp. biting midges. BTV infection of ruminants results in a high viraemia, suggesting that repeated sharing of needles between animals could result in its iatrogenic transmission. Studies defining the risk of iatrogenic transmission of blood-borne pathogens by less invasive routes, such as subcutaneous or intradermal inoculations are rare, even though the sharing of needles is common practice for these inoculation routes in the veterinary sector. Here we demonstrate that BTV can be transmitted by needle sharing during subcutaneous inoculation, despite the absence of visible blood contamination of the needles. The incubation period, measured from sharing of needles, to detection of BTV in the recipient sheep or cattle, was substantially longer than has previously been reported after experimental infection of ruminants by either direct inoculation of virus, or through blood feeding by infected Culicoides. Although such mechanical transmission is most likely rare under field condition, these results are likely to influence future advice given in relation to sharing needles during veterinary vaccination campaigns and will also be of interest for the public health sector considering the risk of pathogen transmission during subcutaneous inoculations with re-used needles

Complete Genome Sequence of Treponema paraluiscuniculi, Strain Cuniculi A: The Loss of Infectivity to Humans Is Associated with Genome Decay

Treponema paraluiscuniculi is the causative agent of rabbit venereal spirochetosis. It is not infectious to humans, although its genome structure is very closely related to other pathogenic Treponema species including Treponema pallidum subspecies pallidum, the etiological agent of syphilis. In this study, the genome sequence of Treponema paraluiscuniculi, strain Cuniculi A, was determined by a combination of several high-throughput sequencing strategies. Whereas the overall size (1,133,390 bp), arrangement, and gene content of the Cuniculi A genome closely resembled those of the T. pallidum genome, the T. paraluiscuniculi genome contained a markedly higher number of pseudogenes and gene fragments (51). In addition to pseudogenes, 33 divergent genes were also found in the T. paraluiscuniculi genome. A set of 32 (out of 84) affected genes encoded proteins of known or predicted function in the Nichols genome. These proteins included virulence factors, gene regulators and components of DNA repair and recombination. The majority (52 or 61.9%) of the Cuniculi A pseudogenes and divergent genes were of unknown function. Our results indicate that T. paraluiscuniculi has evolved from a T. pallidum-like ancestor and adapted to a specialized host-associated niche (rabbits) during loss of infectivity to humans. The genes that are inactivated or altered in T. paraluiscuniculi are candidates for virulence factors important in the infectivity and pathogenesis of T. pallidum subspecies

Prevalence of Influenza A viruses in wild migratory birds in Alaska: Patterns of variation in detection at a crossroads of intercontinental flyways

<p>Abstract</p> <p>Background</p> <p>The global spread of the highly pathogenic avian influenza H5N1 virus has stimulated interest in a better understanding of the mechanisms of H5N1 dispersal, including the potential role of migratory birds as carriers. Although wild birds have been found dead during H5N1 outbreaks, evidence suggests that others have survived natural infections, and recent studies have shown several species of ducks capable of surviving experimental inoculations of H5N1 and shedding virus. To investigate the possibility of migratory birds as a means of H5N1 dispersal into North America, we monitored for the virus in a surveillance program based on the risk that wild birds may carry the virus from Asia.</p> <p>Results</p> <p>Of 16,797 birds sampled in Alaska between May 2006 and March 2007, low pathogenic avian influenza viruses were detected in 1.7% by rRT-PCR but no highly pathogenic viruses were found. Our data suggest that prevalence varied among sampling locations, species (highest in waterfowl, lowest in passerines), ages (juveniles higher than adults), sexes (males higher than females), date (highest in autumn), and analytical technique (rRT-PCR prevalence = 1.7%; virus isolation prevalence = 1.5%).</p> <p>Conclusion</p> <p>The prevalence of low pathogenic avian influenza viruses isolated from wild birds depends on biological, temporal, and geographical factors, as well as testing methods. Future studies should control for, or sample across, these sources of variation to allow direct comparison of prevalence rates.</p

Populations of a Susceptible Amphibian Species Can Grow despite the Presence of a Pathogenic Chytrid Fungus

Disease can be an important driver of host population dynamics and epizootics can cause severe host population declines. Batrachochytrium dendrobatidis (Bd), the pathogen causing amphibian chytridiomycosis, may occur epizootically or enzootically and can harm amphibian populations in many ways. While effects of Bd epizootics are well documented, the effects of enzootic Bd have rarely been described. We used a state-space model that accounts for observation error to test whether population trends of a species highly susceptible to Bd, the midwife toad Alytes obstetricans, are negatively affected by the enzootic presence of the pathogen. Unexpectedly, Bd had no negative effect on population growth rates from 2002–2008. This suggests that negative effects of disease on individuals do not necessarily translate into negative effects at the population level. Populations of amphibian species that are susceptible to the emerging disease chytridiomycosis can persist despite the enzootic presence of the pathogen under current environmental conditions

Epidemiologists working together with anthropologists: lessons from a study to evaluate the epidemiological impact of a city-wide sanitation program

Barreto, Mauricio Lima. Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. “Documento produzido em parceria ou por autor vinculado à Fiocruz, mas não consta à informação no documento”.Pronex-Centres of Excellence Programme CNPq 661086/1998-4Universitat de Barcelona. Departament d’Antropologia Cultural i Història d’Amèrica i Àfrica. Barcelona, España / Universidade Federal da Bahia. Programa de Pós-graduação em Saúde, Ambiente e Trabalho. Salvador, BA, Brasil.Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil.Universidade Federal da Bahia. Instituto de Saúde Coletiva. Salvador, BA, Brasil.Universidade Federal da Bahia. Instituto de Saúde Coletiva. Salvador, BA, Brasil.Este artigo discute o papel das abordagens qualitativas em estudos epidemiológicos, começando com uma discussão geral de ambos os métodos. Centra-se em um estudo de caso sobre o impacto na saúde de uma intervenção ambiental em Salvador, Bahia, Brasil. A maioria de estudos nesta linha, que derivam de pesquisas de fonte primária, traz pouca discussão sobre as questões metodológicas e teóricas envolvidas em estudos em longo prazo. Quatro aspectos específicos dessa experiência são especialmente destacados: (a) elaboração de questionários para o estudo epidemiológico; (b) construção de um instrumento observacional para medir os hábitos de higiene; (c) um estudo etnográfico que antecedeu a pesquisa epidemiológica; (d) observação dos efeitos da intervenção de saúde sobre as desigualdades de saúde. Finalmente, o estudo considera em detalhe como os resultados dos estudos qualitativos e quantitativos podem ser sintetizados. Ele fornece uma visão geral e crítica das estratégias de acompanhamento, ilustrada, sempre que possível, com exemplos apropriados.This paper discusses the role of qualitative approaches in epidemiological studies, beginning with a general discussion of epidemiological and anthropological methods. It focuses on a case study of the health impact of an environmental intervention carried out in Salvador, Bahia State, Brazil. Most of the precedent studies fields, based on primary date, use to devote little attention to the methodological and theorethical questions attached to long-term studies. Four specific aspects of this experience are highlighted: (a) drawing up epidemiological study; (b) construction of an observational instrument to measure hygiene habits; (c) an ethnographic study that was carried out before the epidemiological study; (d) observation of the effects of health intervention on health inequalities. Finally, the report details how the findings of qualitative and quantitative studies might be synthesized. It provides a critical overview of follow-up strategies, illustrated with proper examples whenever possible.En este artículo se discute el papel de los enfoques cualitativos en los estudios epidemiológicos, comenzando con una discusión general de ambos métodos. Se centra en un estudio de caso sobre el impacto en la salud de una intervención ambiental en Salvador, Bahía, Brasil. La mayoría de los estudios en esta línea, que se deriven de la fuente principal de la investigación, aporta poca discusión sobre los aspectos metodológicos y teóricos que participan en estudios a largo plazo. Cuatro aspectos específicos de esta experiencia son especialmente prominentes: (a) elaboración de cuestionarios para el estudio epidemiológico; (b) la construcción de un instrumento para medir los hábitos de higiene de observación; (c) un estudio etnográfico que precedió a la investigación epidemiológica; (d) observación de los efectos de las intervenciones sanitarias sobre las desigualdades en salud. Por último, el estudio considera en detalle cómo los resultados de los estudios cualitativos y cuantitativos se pueden sintetizar. Proporciona una visión general y crítica de estrategias de seguimiento, ilustraciones siempre que sea posible, con ejemplos apropiados