Nipah virus circulation at human-bat interfaces, Cambodia.

OBJECTIVE: To better understand the potential risks of Nipah virus emergence in Cambodia by studying different components of the interface between humans and bats. METHODS: From 2012 to 2016, we conducted a study at two sites in Kandal and Battambang provinces where fruit bats (Pteropus lylei) roost. We combined research on: bat ecology (reproductive phenology, population dynamics and diet); human practices and perceptions (ethnographic research and a knowledge, attitude and practice study); and Nipah virus circulation in bat and human populations (virus monitoring in bat urine and anti-Nipah-virus antibody detection in human serum). FINDINGS: Our results confirmed circulation of Nipah virus in fruit bats (28 of 3930 urine samples positive by polymerase chain reaction testing). We identified clear potential routes for virus transmission to humans through local practices, including fruit consumed by bats and harvested by humans when Nipah virus is circulating, and palm juice production. Nevertheless, in the serological survey of 418 potentially exposed people, none of them were seropositive to Nipah virus. Differences in agricultural practices among the regions where Nipah virus has emerged may explain the situation in Cambodia and point to actions to limit the risks of virus transmission to humans. CONCLUSION: Human practices are key to understanding transmission risks associated with emerging infectious diseases. Social science disciplines such as anthropology need to be integrated in health programmes targeting emerging infectious diseases. As bats are hosts of major zoonotic pathogens, such integrated studies would likely also help to reduce the risk of emergence of other bat-borne diseases.

Traditional Khmer Medicine and its role in wildlife use in modern-day Cambodia.

Individuals across Cambodia depend on the use of natural products in Traditional Khmer Medicine (TKM), a traditional medicine system in Cambodia that has been practiced for hundreds of years. Cambodia is rich in fauna and flora species, many of which have been, and continue to be, traded domestically for traditional medicine use. Combined with other known exploitative practices, such as snaring for wild meat consumption and international trade in wildlife, domestic trade in wildlife medicine threatens populations of regional conservation importance. Here, we provide an updated understanding about how TKM is practiced in modern times; how TKM practices are transmitted and adapted; and roles of wildlife part remedies in TKM historically and presently. We conducted semi-structured interviews with TKM practitioners in Stung Treng, Mondulkiri Province, and at the National Center for Traditional Medicine in Phnom Penh, the capital of Cambodia. TKM is generally practiced in the private sector and is mostly informal, without enrollment in any academic training. TKM practitioner roles commonly involve collecting, preparing, selling, and advising on medicine, rather than providing direct treatment. Over half of the interviewed TKM practitioners (57.6%) were still prescribing wildlife parts as medicine over the past 5 years, with 28 species of wild animals reported. Lorises and porcupine were the wildlife products cited as being in highest demand in TKM, primarily prescribed for women's illnesses such as post-partum fatigue (Toas and Sawsaye kchey). However, the supply of wildlife products sourced from the wild was reported to have dropped in the 5 years prior to the survey, which represents an opportunity to reduce prescription of threatened wildlife. We suggest that our results be used to inform tailored demand reduction interventions designed to encourage greater reliance on biomedicine and non-threatened plants, particularly in rural areas where use of biomedicine may still be limited.

Longitudinal monitoring in Cambodia suggests higher circulation of alpha and betacoronaviruses in juvenile and immature bats of three species.

Recent studies suggest that coronaviruses circulate widely in Southeast Asian bat species and that the progenitors of the SARS-Cov-2 virus could have originated in rhinolophid bats in the region. Our objective was to assess the diversity and circulation patterns of coronavirus in several bat species in Southeast Asia. We undertook monthly live-capture sessions and sampling in Cambodia over 17 months to cover all phases of the annual reproduction cycle of bats and test specifically the association between their age and CoV infection status. We additionally examined current information on the reproductive phenology of Rhinolophus and other bat species presently known to occur in mainland southeast China, Vietnam, Laos and Cambodia. Results from our longitudinal monitoring (573 bats belonging to 8 species) showed an overall proportion of positive PCR tests for CoV of 4.2% (24/573) in cave-dwelling bats from Kampot and 4.75% (22/463) in flying-foxes from Kandal. Phylogenetic analysis showed that the PCR amplicon sequences of CoVs (n = 46) obtained clustered in Alphacoronavirus and Betacoronavirus. Interestingly, Hipposideros larvatus sensu lato harbored viruses from both genera. Our results suggest an association between positive detections of coronaviruses and juvenile and immature bats in Cambodia (OR = 3.24 [1.46-7.76], p = 0.005). Since the limited data presently available from literature review indicates that reproduction is largely synchronized among rhinolophid and hipposiderid bats in our study region, particularly in its more seasonal portions (above 16° N), this may lead to seasonal patterns in CoV circulation. Overall, our study suggests that surveillance of CoV in insectivorous bat species in Southeast Asia, including SARS-CoV-related coronaviruses in rhinolophid bats, could be targeted from June to October for species exhibiting high proportions of juveniles and immatures during these months. It also highlights the need to develop long-term longitudinal surveys of bats and improve our understanding of their ecology in the region, for both biodiversity conservation and public health reasons.

Bear bile use at the intersection of maternal health in Cambodia.

BACKGROUND: The consumption of bear gallbladders and bear bile in Southeast Asia is a persistent threat to bear populations. As part of a larger effort to understand the characteristics of bear part consumption in Cambodia, we uncovered a consumer base of women seeking treatment for post-partum and uterine ailments. METHODS: To better understand this aspect of consumption, we interviewed 122 women in seven different provinces in Cambodia, probing into the motivations and influences for using bear bile, as well as what types of ailments Cambodian women use it for. RESULTS: We found that it is generally used by young or expecting mothers, and for such issues as post-partum "fatigue" (toas in Khmer), which could encompass post-partum depression. A desire to be supported by kin networks seems to facilitate the continued use of bear gallbladder and bile for these purposes. CONCLUSIONS: We suggest that efforts to reduce consumption should focus on encouraging older kin to change their means of support to Western/biomedical and by extension non-wildlife alternatives.

Correction: Understanding the prevalence of bear part consumption in Cambodia: A comparison of specialised questioning techniques.

[This corrects the article DOI: 10.1371/journal.pone.0211544.].

Correction: Understanding the prevalence of bear part consumption in Cambodia: A comparison of specialised questioning techniques.

[This corrects the article DOI: 10.1371/journal.pone.0211544.].

Understanding the prevalence of bear part consumption in Cambodia: A comparison of specialised questioning techniques.

The trade in bear parts for medicine and for status is a conservation challenge throughout Asia. The Asiatic black bear (Ursus thibetanus) and the sun bear (Helarctos malayanus) are endemic to this region, and populations are estimated to have declined throughout their ranges due to widespread illegal killing of bears and trade in parts, combined with loss of habitat. Previous studies have indicated that legislation alone is insufficient to prevent illegal hunting and trade, indicating instead a need to address demand for bear parts and products. We conducted mixed-method surveys in Cambodia to understand the key motivators for individuals to consume bear parts, and to understand whether specialised questioning techniques are applicable in this context. Bear part use is illegal in Cambodia and may therefore be considered a sensitive behaviour, in that individuals may be reluctant to admit to it. To counteract possible biases, four specialised questioning techniques were used in this study: randomised response technique (RRT), unmatched count technique (UCT), nominative technique (NT), and false consensus bias (FCB). All four methods serve to shield a respondent's admittance of a sensitive behaviour from the interviewer. The results presented here show that great variability exists in anonymous methods' efficacy in certain contexts. However, the results overall indicate that individuals in Cambodia are under-reporting their consumption of bear parts when directly asked, and that the prevalence of bear part use in Cambodia may be as high as 15% of the population, representing a significant conservation challenge.

Insectivorous bat reproduction and human cave visitation in Cambodia: A perfect conservation storm?

Cave roosting bats represent an important component of Southeast Asian bat diversity and are vulnerable to human disturbance during critical reproductive periods (pregnancy, lactation and weaning). Because dramatic growth of cave tourism in recent decades has raised concerns about impacts on cave bats in the region, we assessed the reproductive phenology of two insectivorous species (Hipposideros larvatus sensu lato and Taphozous melanopogon) at three caves in Cambodia for 23 months in 2014-2016 and evaluated human visitation to these sites between 2007 and 2014. Despite the differing foraging strategies employed by the two taxa, the temporal consistency observed in proportions of pregnant, lactating and juvenile bats indicates that their major birth peaks coincide with the time of greatest cave visitation annually, particularly for domestic visitors and namely during the Cambodian new year in April. They also reflect rainfall patterns and correspond with the reproductive phenology of insectivorous cave bats in Vietnam. These findings were predictable because 1) insect biomass and thus food availability for insectivorous bats are optimal for ensuring survival of young following this period, and 2) the Khmer new year is the most significant month for religious ceremonies and thus domestic cave visitation nationally, due to the abundance of Buddhist shrines and temples in Cambodian caves. While the impact of visitor disturbance on bat population recruitment cannot be empirically assessed due to lack of historical data, it is nonetheless likely to have been considerable and raises a conservation concern. Further, because growing evidence suggests that insectivorous cave bats exhibit reproductive synchrony across continental Southeast Asia where countless cave shrines are heavily frequented during April in Theravada Buddhist countries (e.g., Myanmar, Thailand, Cambodia and Laos), our results may have wider applicability in the region. We consequently advocate for increased emphasis on sustainable cave management practices in Cambodia and further investigations to determine whether our findings present a broader concern for cave bat conservation in Southeast Asia.