Natural infection of leptospirosis and melioidosis in long-tailed macaques (<i>Macaca fascicularis</i>) in Thailand

Abstract

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.

Leptospira Seroprevalence in Free-Ranging Long-Tailed Macaques (Macaca fascicularis) at Kosumpee Forest Park, Maha Sarakham, Thailand

“…This finding is concordant with a previous study that revealed that the most general serovars in humans and livestock in Thailand were Shermani, Ranarum, and Sejroe [ 26 ]. Leptospira serovars Ranarum and Shermani were also be found in long-tailed macaques inhabiting Southern, Central, and Eastern regions of Thailand, as described in a recent study [ 21 ]. Additionally, Leptospira serovar Sejroe was reported to be circulating in cattle in Maha Sarakham province [ 6 ], which represents the same general study area as this current study.…”

“…that were found in the long-tailed macaques at Kosumpee Forest Park, the possibility exists that these macaques act as natural reservoir hosts for leptospirosis. Given the close contact between the macaques and local resident in this shared environment, the opportunity for cross-transmission of zoonotic pathogens presents a real concern; one that also has been noted by others [ 20 , 21 ]. The occurrence of Leptospira seropositivity from the long-tailed macaques in this study (13.33%) was lower than what has been found in some recent studies from other countries, including Southern, Central, and Eastern Thailand, with 48 out of 223 (21.52%) long-tailed macaques [ 21 ]; 8 out of the 12 monkeys (66.66%) from Sarawak, Malaysia [ 22 ]; 39 out of 83 wild African green monkeys (47%) on the Caribbean island of Saint Kitts, India [ 23 ]; 16 out of 52 capuchin monkeys (30.77%) from Colombia [ 24 ]; and 39 out of 50 tufted capuchin monkeys (78%) from Southeast Sao Paulo state, Brazil [ 25 ].…”

Combining isothermal recombinase polymerase amplification with lateral flow assay for diagnosis of P. cynomolgi malaria infection

“…The gDNA was extracted directly from samples using GeneJET Whole Blood Genomic DNA Purification Mini Kit (Thermo Fisher Scientific, USA) and stored at −20°C until use. In our previous study, all gDNA samples showed negative results for dengue virus (DENV), Zika virus (ZIKV), Chikungunya virus (CHIKV), Leptospira spp., and Burkholderia pseudomallei using molecular detection [ 17 , 18 ]. To analyze Plasmodium species, a nested PCR approach was employed, following the previously described method [ 19 ].…”

A mathematical model analysis of the human melioidosis transmission dynamics with an asymptomatic case

“…Melioidosis is a tropical infectious disease caused by an aerobic, gram-negative bacterium called Burkholderia pseudomallei ( Ross et al, 2018 ; Mahikul et al, 2019 ; Saechan et al, 2022 ). It is reported mostly known as endemic, with a high number of cases and rate of mortality in numerous nations of the world including Thailand, Singapore, Malaysia, India, Bangladesh and China ( Currie and Kaestli, 2016 ; Luangasanatip et al, 2019 ; Chowdhury et al, 2022 ).…”