Seroprevalence of Japanese Encephalitis Virus in Pigs and Cattle: An Evaluation from Tangerang Regency

Abstract

Japanese encephalitis (JE) is a zoonotic vector-borne disease in humans and animals in the Asia Pacific. This RNA virus is transmitted to humans through mosquito bites from viral amplifiers, such as pigs, poultry, bats, and other vertebrates. In the spread of JEV, herons are considered the reservoir, pigs as the main amplifying host, and the Culex mosquito as a vector. Although the number of cases of JE in humans is low, Indonesia is considered an endemic area for JE. The purpose of this study was to evaluate the seroprevalence of JE in pigs and cattle in Tangerang Regency, the area with the largest pig population in Banten Province. From June -to July 2019, a total of 101 samples of pig blood and 110 samples of cattle blood were collected from 13 pig farms and 42 cattle farms. Characteristics of livestock management were recorded for further descriptive analysis. From 101 samples of pig blood and 110 samples of cattle blood, only 94 pig serum and 94 cattle serum were obtained for testing by Japanese encephalitis virus (JEV) Specific IgG ELISA; the seroprevalence results for pigs were 6.38% and 7.44% for cattle. The follow-up PCR test for porcine and bovine serum found none of the samples with the JE virus. Based on seroprevalence results and livestock management characteristics, we suspect that the JE antibody in reactive pig serum was inherited from their sow before being imported from outside the Tangerang district. However, judging from the location of the source of the positive JEV IgG cattle, almost all of which were obtained locally, there is a possibility that JEV transmission occurred in Tangerang Regency. We suggest the need for JE virus control in breeding farms in the area of origin of pigs that enter the Tangerang Regency area, considering that the introduction of the virus can occur through the transportation of cattle or piglets between regions.