Seroprevalence of swine hepatitis E virus and the farmers’ potential risk of infection in the Province of Bali, Indonesia

Vet World Vol.17 August-2024 Article - 18

Research Article

Veterinary World, 17(8): 1810-1820

https://doi.org/10.14202/vetworld.2024.1810-1820

I Made Kardena¹, Anak Agung Gde Oka Dharmayudha², I Wayan Nico Fajar Gunawan², Putu Devi Jayanti², I Nyoman Mantik Astawa¹, Anak Agung Ayu Mirah Adi¹, I Nyoman Suarsana³, I Nyoman Suartha², and Alan P. Dargantes⁴

1. Department of Pathobiology, Faculty of Veterinary Medicine, Udayana University, Jalan PB Sudirman, Denpasar, Bali, 80234, Indonesia.
2. Department of Veterinary Clinic, Faculty of Veterinary Medicine, Udayana University, Jalan PB Sudirman, Denpasar, Bali, 80234, Indonesia.
3. Department of Veterinary Basic Science, Faculty of Veterinary Medicine, Udayana University, Jalan PB Sudirman, Denpasar, Bali, 80234, Indonesia.
4. Department of Medicine, Surgery & Zootechnics, College of Veterinary Medicine, Central Mindanao University, Musuan, Maramag, Bukidnon, 8714, The Philippines.

Background and Aim: Hepatitis E virus (HEV) infection formerly and predominantly occurred in rural areas. However, it has recently been spread to urban and peri-urban areas. This study aimed to estimate the seroprevalence of HEV in pigs collected from urban and rural areas in Bali. The potential of the pig farmers’ risk level for being exposed to HEV and the virus transmitted to them in association with their pig-rearing practices was also assessed.

Materials and Methods: A total of 183 pigs from 68 herds were sampled in this study, with 91 pigs collected from Denpasar as the representative samples of urban areas and 92 pigs from Karangasem Regency as the representative samples from rural areas. Sera from the sampled pigs were collected and immunoglobulin G antibodies against HEV were detected using a commercial enzyme-linked immunosorbent assay. A questionnaire was prepared for interviewing the farmers. Bivariable and multivariable logistic regression analyses were performed to identify the putative factors associated with seropositivity. Meanwhile, the potential risk-incurring practices of the farmers for HEV being transmitted to them from their pig-rearing practices were assessed by scoring their responses from the interview.

Results: Overall, 23.5% (43/183) (95% confidence interval [CI]: 17.6–30.3) pig sera tested were detected to have the antibodies against HEV. Among 68 pig herds, 36.8% (25) (95% CI: 25.4–49.3) of them had antibodies in at least one pig sampled from each herd. Pigs sampled from Karangasem were 5 times (Odds ratio [OR] 5.34, 95% CI: 2.27–13.54, p < 0.001) more likely to be seropositive than pigs collected from Denpasar. However, no difference was found in the seropositivity to HEV in pig herds between Denpasar and Karangasem (p = 0.05). In assessing the pig rearing management factors, pig farmers from Denpasar were 3 times (OR 3.0, 95% CI: 1.07–8.52, p = 0.05) more likely to rear pigs for economic investment compared to the farmers from Karangasem. Regarding anticipating pig diseases that can be transmitted to humans, farmers from Denpasar were 6 times (OR 5.72, 95% CI: 1.48–26.7, p = 0.0074) more likely to anticipate zoonotic diseases compared to the farmers from Karangasem. Similarly, pig farmers from Denpasar were 3 times (OR 3.29, 95% CI: 1.08–10.23, p = 0.035) more likely to anticipate pig diseases that could be transmitted to humans than the farmers from Karangasem. Pig farmers from Denpasar had 4 times the odds (OR 4.49, 95% CI: 1.11–18.19, p = 0.03) of washing their hands after going to the pigpens compared to the farmers from Karangasem. All the participants were categorized as being at high risk of HEV exposure and transmission.

Conclusion: IgG antibodies against HEV were detected among pigs reared in rural areas of Karangasem and those reared in urban areas of Denpasar. This suggests that the risk of HEV exposure and transmission in these areas is not negligible. To minimize the risk, public education on zoonotic diseases, including HEV infection, transmission, and prevention, needs to be implemented and particularly targeted to local pig farmers.

Keywords: Bali, hepatitis E virus, pigs, risk factors, seroprevalence.

How to cite this article: Kardena IM, Dharmayudha AAGO, Gunawan IWNF, Jayanti PD, Astawa INM, Adi AAAM, Suarsana IN, Suartha IN, and Dargantes AP (2024) Seroprevalence of swine hepatitis E virus and the farmers’ potential risk of infection in the Province of Bali, Indonesia, Veterinary World, 17(8): 1810–1820.

Received: 2024-04-08 Accepted: 2024-07-15 Published online: 2024-08-20

Corresponding author: I Made Kardena E-mail: imadekardena@unud.ac.id

DOI: 10.14202/vetworld.2024.1810-1820

Copyright: Kardena, 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.