The Endangered dhole Cuon alpinus is a medium-sized canid that was historically distributed widely across East, Central, South and Southeast Asia. In Nepal, following heavy persecution during the ...1970s and 1980s, the species was locally extirpated across large parts of the country. After decades of near absence, the dhole is reportedly showing signs of recovery in various areas of Nepal. We carried out three surveys using camera traps (resulting in a total of 6,550 camera-trap days), reviewed literature and interviewed herders and conservation practitioners (40 interviews) to determine the historical and current distribution of dholes in the country, and the species’ current status. Our camera traps recorded five images of dholes, and the literature review and interview survey provided further insights into the historical and current presence of dholes in Nepal. The combined findings suggest dholes have recolonized many areas where they had been locally extirpated, such as the Annapurna Conservation Area in central Nepal and the Tinjure–Milke–Jaljale forests in the eastern part of the country. Although these returns are encouraging, challenges remain for dhole recolonization, including conflict with livestock herders, human hunting of wild ungulates affecting the species’ prey base, increasing infrastructure development in forested areas, and diseases.
Wild aquatic birds are recognized as the natural reservoir of avian influenza A viruses (AIV), but across high and low pathogenic AIV strains, scientists have yet to rigorously identify most ...competent hosts for the various subtypes. We examined 11,870 GenBank records to provide a baseline inventory and insight into patterns of global AIV subtype diversity and richness. Further, we conducted an extensive literature review and communicated directly with scientists to accumulate data from 50 non-overlapping studies and over 250,000 birds to assess the status of historic sampling effort. We then built virus subtype sample-based accumulation curves to better estimate sample size targets that capture a specific percentage of virus subtype richness at seven sampling locations. Our study identifies a sampling methodology that will detect an estimated 75% of circulating virus subtypes from a targeted bird population and outlines future surveillance and research priorities that are needed to explore the influence of host and virus biodiversity on emergence and transmission.
1. Rapid population declines of the vultures Gyps bengalensis, Gyps indicus and Gyps tenuirostris have recently been observed in India and Pakistan, continuing at least up to 2003. Surveys indicate ...annual rates of decline of 22-50% for G. bengalensis and G. indicus during 2000-03. Previous studies in Pakistan have shown that the non-steroidal anti-inflammatory drug diclofenac causes renal failure and is lethal to G. bengalensis when it feeds on the carcass of a domestic animal that received a normal veterinary dose shortly before death. In Pakistan, diclofenac poisoning was found to be by far the most frequent cause of death. 2. A simulation model of vulture demography, described in this paper, demonstrated that the observed rates of population decline could be caused by contamination with a lethal level of diclofenac in a small proportion (between 1: 130 and 1: 760) of ungulate carcasses available to vultures. 3. Proportions of adult and subadult vultures found dead or dying in the wild that had signs of diclofenac poisoning were similar to the proportions of deaths expected from the model if the observed population decline was due entirely to diclofenac poisoning. The proportion of the excess mortality required to cause the observed population declines that could be attributable to diclofenac was estimated to be between 71% and 100%, depending on model assumptions. However, across all or most of the plausible range of assumed values for adult survival, the upper 95% confidence limit for the proportion of excess mortality due to diclofenac was 100%. Hence, available data are consistent with diclofenac poisoning being at least the major cause, and possibly the only cause, of rapid population declines of Gyps vultures across the Indian subcontinent. 4. Synthesis and applications. We recommend that urgent action is taken in the range states of the three currently threatened vulture species to prevent the exposure of vultures to livestock carcasses contaminated with diclofenac. Research is also needed to identify alternative drugs that are effective in livestock and safe for vultures. Efforts should also be made to raise awareness, among veterinarians, pharmacists, livestock owners and the general public, of the problem of diclofenac contamination and the availability of safe alternatives. Captive holding and breeding of vultures until diclofenac is controlled is recommended as a precaution to ensure the long-term survival of the threatened species and to provide a stock of birds for future reintroduction programmes.
Avian Coronavirus in Wild Aquatic Birds CHU, Daniel K. W; LEUNG, Connie Y. H; GILBERT, Martin ...
Journal of Virology,
12/2011, Letnik:
85, Številka:
23
Journal Article
Lethal infections with canine distemper virus (CDV) have recently been diagnosed in Amur tigers (Panthera tigris altaica), but long-term implications for the population are unknown. This study ...evaluates the potential impact of CDV on a key tiger population in Sikhote-Alin Biosphere Zapovednik (SABZ), and assesses how CDV might influence the extinction potential of other tiger populations of varying sizes. An individual-based stochastic, SIRD (susceptible-infected-recovered/dead) model was used to simulate infection through predation of infected domestic dogs, and/or wild carnivores, and direct tiger-to-tiger transmission. CDV prevalence and effective contact based on published and observed data was used to define plausible low- and high-risk infection scenarios. CDV infection increased the 50-year extinction probability of tigers in SABZ by 6.3% to 55.8% compared to a control population, depending on risk scenario. The most significant factors influencing model outcome were virus prevalence in the reservoir population(s) and its effective contact rate with tigers. Adjustment of the mortality rate had a proportional impact, while inclusion of epizootic infection waves had negligible additional impact. Small populations were found to be disproportionately vulnerable to extinction through CDV infection. The 50-year extinction risk in populations consisting of 25 individuals was 1.65 times greater when CDV was present than that of control populations. The effects of density dependence do not protect an endangered population from the impacts of a multi-host pathogen, such as CDV, where they coexist with an abundant reservoir presenting a persistent threat. Awareness of CDV is a critical component of a successful tiger conservation management policy.
Abstract
Scirtothrips aurantii Faure (Thysanoptera: Thripidae) is a major pest of citrus fruit in subtropical southern Africa. Population monitoring is an important aspect of S. aurantii control, but ...additional information is required on its phenology. Dispersal of mature larvae onto the soil surface from the tree canopy, and emergence of adults, were assessed using dispersal/emergence (D/E) traps in an untreated citrus orchard in South Africa. Overall, 90.7% of adult Thysanoptera emerging from soil / leaf litter beneath the citrus trees were S. aurantii, of which 35.7% were males, and 64.3% were females. Female S. aurantii having survived winter as adults oviposited on the early spring flush. This resulted in the first population peak of larvae dropping to the ground to pupate and adults emerging in spring, September to early October, as the first vegetative flush of the citrus-growing season hardened, and fruit was set as blossoming ended. Initial infestation of young fruit occurred after a build-up of larval numbers on the soft citrus flush late July to early August. The second generation larval and adult peak occurred late November to early December, whether there was new flush or not, as young fruit could support the S. aurantii population. A third peak occurred mid-December to late January, depending on year. Thus, there were three generations of S. aurantii during the period of citrus fruit susceptibility to thrips damage (September–January). After the autumn flush in April, another peak of larvae and adults occurred before the population declined to a minimum from May to July.
Although the majority of emerging infectious diseases can be linked to wildlife sources, most pathogen spillover events to people could likely be avoided if transmission was better understood and ...practices adjusted to mitigate risk. Wildlife trade can facilitate zoonotic disease transmission and represents a threat to human health and economies in Asia, highlighted by the 2003 SARS coronavirus outbreak, where a Chinese wildlife market facilitated pathogen transmission. Additionally, wildlife trade poses a serious threat to biodiversity. Therefore, the combined impacts of Asian wildlife trade, sometimes termed bush meat trade, on public health and biodiversity need assessing. From 2010 to 2013, observational data were collected in Lao PDR from markets selling wildlife, including information on volume, form, species and price of wildlife; market biosafety and visitor origin. The potential for traded wildlife to host zoonotic diseases that pose a serious threat to human health was then evaluated at seven markets identified as having high volumes of trade. At the seven markets, during 21 observational surveys, 1,937 alive or fresh dead mammals (approximately 1,009 kg) were observed for sale, including mammals from 12 taxonomic families previously documented to be capable of hosting 36 zoonotic pathogens. In these seven markets, the combination of high wildlife volumes, high risk taxa for zoonoses and poor biosafety increases the potential for pathogen presence and transmission. To examine the potential conservation impact of trade in markets, we assessed the status of 33,752 animals observed during 375 visits to 93 markets, under the Lao PDR Wildlife and Aquatic Law. We observed 6,452 animals listed by Lao PDR as near extinct or threatened with extinction. The combined risks of wildlife trade in Lao PDR to human health and biodiversity highlight the need for a multi-sector approach to effectively protect public health, economic interests and biodiversity.
With the COVID-19 pandemic, vaccines have been administered all around the world probably more than ever. Even though they are considered safe, with such a huge quantity of doses used, many adverse ...effects including cutaneous ones were reported. We report here the case of a male adult with a history of monoclonal gammopathy of undetermined significance who presented with an extensive cutaneous eruption of indurated erythematous papules and plaques 2 days after receiving his first dose of Moderna COVID-19 vaccine (mRNA-1273 SARS-CoV-2 vaccine). Histopathology was compatible with a histiocytoid Sweet syndrome and history suggested that the vaccine contributed to the eruption.
Virus ecology and evolution play a central role in disease emergence. However, their relative roles will vary depending on the viruses and ecosystems involved. We combined field studies, ...phylogenetics and experimental infections to document with unprecedented detail the stages that precede initial outbreaks during viral emergence in nature. Using serological surveys we showed that in the absence of large-scale outbreaks, horses in Mongolia are routinely exposed to and infected by avian influenza viruses (AIVs) circulating among wild birds. Some of those AIVs are genetically related to an avian-origin virus that caused an epizootic in horses in 1989. Experimental infections showed that most AIVs replicate in the equine respiratory tract without causing lesions, explaining the absence of outbreaks of disease. Our results show that AIVs infect horses but do not spread, or they infect and spread but do not cause disease. Thus, the failure of AIVs to evolve greater transmissibility and to cause disease in horses is in this case the main barrier preventing disease emergence.
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