Vet World Vol.15 May-2022 Article-25
Research Article
Veterinary World, 15(5): 1341-1346
https://doi.org/10.14202/vetworld.2022.1341-1346
First survey on seroprevalence of Japanese encephalitis in long-tailed macaques (Macaca fascicularis) in Bali, Indonesia
2. Primate Research Center, Udayana University, Kampus Bukit, Jimbaran, Badung, Bali, Indonesia.
3. Laboratory of Veterinary Pathology, Faculty of Veterinary Medicine, Udayana University, Kampus Sudirman, Jalan PB Sudirman, Denpasar, Bali, Indonesia.
4. Laboratory of Veterinary Virology, Faculty of Veterinary Medicine, Udayana University, Kampus Sudirman, Jalan PB Sudirman, Denpasar, Bali, Indonesia.
5. Research Unit SPHERES, Department of Biology, Ecology, and Evolution, University of Liege, Belgium.
6. Department of Anthropology, Princeton University, 123 Aaron Burr Hall, Princeton NJ 08544, United States.
Background and Aim: Japanese encephalitis (JE) is a zoonotic infectious inflammatory brain disease caused by the JE virus (JEV). Considerable research into the seroprevalence of JE in domestic animals has been conducted, but there have been no reports of its occurrence in wild animals, including long-tailed macaques (Macaca fascicularis). This study aimed to estimate the seroprevalence of JEV infection and its determinants in long-tailed macaques in Bali and the prevalence of mosquito vectors.
Materials and Methods: Blood samples (3 mL) were collected from a population of M. fascicularis (92 heads) inhabiting a small forest with irrigated rice field nearby (wetland area) in Ubud, Gianyar, and from two populations in dryland areas with no wet rice field (Uluwatu, Badung, and Nusa Penida, Bali Province, Indonesia). The collected sera were tested for antibodies against JEV using a commercially available enzyme-linked immunosorbent assay kit (qualitative monkey JE Immunoglobulin G antibody kit). The seropositivity of the antibodies was then compared based on different variables, namely, habitat type, age, and sex.
Results: The seroprevalence of the JEV antibodies in all the samples tested was found to be 41.3%. The seropositivity of the monkey serum samples collected from the wetland area was 46.4%, which was higher than the seropositivity of the sera samples collected from the dried field areas (1.25%). Monkey sera collected from the wetland areas were 6.1 times (odds ratio [OR]: 6.1; 95% confidence interval [CI]: 0.71-51.5, p>0.05) more likely to be seropositive compared to the monkey sera collected from the dried field areas. Meanwhile, female monkeys were 1.79 times (OR: 1.79; 95% CI: 0.76-4.21; p>0.05) more likely to be seropositive to JEV than males. Similarly, juvenile monkeys were 2.38 times (OR: 2.38; 95% CI: 0.98-5.79); p>0.05) more likely to be seropositive against the JEV than adult monkeys. However, none of these differences achieved statistical significance. Regarding the JEV mosquito vector collection, more Culex mosquitoes were found in the samples from the wetland areas than from the dried field areas.
Conclusion: The study confirms the existence of JEV infection in long-tailed macaques in Bali. There were patterned seropositivity differences based on habitat, age, and sex of the monkeys, but these were not significant. The possibility of monkeys as a JEV reservoir and the presence of the mosquitoes as the JEV vector are suggested but require more study to confirm. Keywords: enzyme-linked immunosorbent assay, Japanese encephalitis virus, Macaca fascicularis, seroprevalence.
Keywords: enzyme-linked immunosorbent assay, Japanese encephalitis virus, Macaca fascicularis, seroprevalence.
How to cite this article: Putra IGAA, Adi AAAM, Astawa INM, Kardena IM, Wandia IN, Soma IG, Brotcorne F, Fuentes A (2022) First survey on seroprevalence of Japanese encephalitis in long-tailed macaques (Macaca fascicularis) in Bali, Indonesia, Veterinary World, 15(5): 1341-1346.
Received: 17-01-2022 Accepted: 18-04-2022 Published online: 27-05-2022
Corresponding author: I Gusti Agung Arta Putra E-mail: artaputra@unud.ac.id
DOI: 10.14202/vetworld.2022.1341-1346
Copyright: Putra IGAA, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.