Coincidence of low genetic diversity and increasing population size in wild gaur populations in the Khao Phaeng Ma Non-Hunting Area, Thailand: A challenge for conservation management under human-wildlife conflict.

The gaur (Bos gaurus) is found throughout mainland South and Southeast Asia but is listed as an endangered species in Thailand with a decreasing population size and a reduction in suitable habitat. While gaur have shown a population recovery from 35 to 300 individuals within 30 years in the Khao Phaeng Ma (KPM) Non-Hunting Area, this has caused conflict with villagers along the border of the protected area. At the same time, the ecotourism potential of watching gaurs has boosted the local economy. In this study, 13 mitochondrial displacement-loop sequence samples taken from gaur with GPS collars were analyzed. Three haplotypes identified in the population were defined by only two parsimony informative sites (from 9 mutational steps of nucleotide difference). One haplotype was shared among eleven individuals located in different subpopulations/herds, suggesting very low genetic diversity with few maternal lineages in the founder population. Based on the current small number of sequences, neutrality and demographic expansion test results also showed that the population was likely to contract in the near future. These findings provide insight into the genetic diversity and demography of the wild gaur population in the KPM protected area that can inform long-term sustainable management action plans.

Natural infection of leptospirosis and melioidosis in long-tailed macaques (Macaca fascicularis) in Thailand.

This study aimed to determine the incidence of leptospirosis and melioidosis in long-tailed macaques (Macaca fascicularis) in Thailand. Serum samples from 223 monkeys were subjected to the Lepto Latex Test and indirect hemagglutination (IHA) test to detect antibodies against Leptospira spp. and Burkholderia pseudomallei. The microagglutination test (MAT) was used to identify serovars of Leptospira spp. Conventional PCR for the LipL32 gene of L. interogans and the BPSS0120 and btfc-orf18 genes of B. pseudomallei was used for molecular detection. The overall seroprevalence of leptospirosis and melioidosis was 2.69% (95% confidence interval (CI): 0.99-5.76%) and 14.35% (95% CI: 10.03-19.65%), respectively. Six samples that showed positive MAT results were also positive for IHA. The serovars of Leptospira were Ranarum (5/6), Shermani (6/6), and both (5/6). Conventional PCR for the LipL32 gene of Leptospira spp. was positive in 10.31% of the samples (95% CI: 5.56-13.51%). However, there were no positive results for BPSS0120 and btfc-orf18 in B. pseudomallei. Active infection was detected only for leptospirosis; however, it can be assumed that pathogen exposure occurred in this group of animals because immunity could be detected. The routes of infection and elimination pathways of both bacteria remain unclear, and the mechanism of protection in non-human primates needs to be elucidated in further studies. Moreover, this health issue should be considered to prevent human infections in monkeys and their environment.

Seroprevalence of Dengue, Zika, and Chikungunya Viruses in Wild Monkeys in Thailand.

Zoonotic pathogens such as arboviruses have comprised a significant proportion of emerging infectious diseases in humans. The role of wildlife species as reservoirs for arboviruses is poorly understood, especially in endemic areas such as Southeast Asia. This study aims to determine the exposure history of different macaque species from national parks in Thailand to mosquito-borne flaviviruses and alphavirus by testing the serum samples collected from 25 northern pigtailed macaques, 33 stump-tailed macaques, and 4 long-tailed macaques for the presence of antibodies against dengue, Zika, and chikungunya viruses by plaque reduction neutralization assay. Specific neutralizing antibodies against Dengue virus (DENV1-4) and Zika virus (ZIKV) were mainly found in stump-tailed macaques, whereas neutralizing antibody titers were not detected in long-tailed macaques and pigtailed macaques as determined by 90% plaque reduction neutralization assay (PRNT90). One long-tailed macaque captured from the south of Thailand exhibited antibody titers against chikungunya virus (CHIKV), suggesting enzootic of this virus to nonhuman primates (NHPs) in Thailand. Encroachment of human settlements into the forest has increased the interface that exposes humans to zoonotic pathogens such as arboviruses found in monkeys. Nonhuman primates living in different regions of Thailand showed different patterns of arboviral infections. The presence of neutralizing antibodies among wild monkeys in Thailand strongly suggests the existence of sylvatic cycles for DENV, ZIKV, and CHIKV in Thailand. The transmission of dengue, Zika, and chikungunya viruses among wild macaques may have important public health implications.