Kardena I Made, Adi Anak Agung Ayu Mirah, Astawa I Nyoman Mantik, Oka Ida Bagus Made, Sahibzada Shafi, Bruce Mieghan, O'Dea Mark
Department of Pathobiology, Faculty of Veterinary Medicine, Udayana University, Jalan PB Sudirman, Denpasar, Bali, 80234, Indonesia.
School of Veterinary Medicine and Centre for Biosecurity and One Health, Harry Butler Institute, Murdoch University, Perth, Western Australia, 6150, Australia.
Vet World. 2024 Jan;17(1):89-98. doi: 10.14202/vetworld.2024.89-98. Epub 2024 Jan 8.
Despite the endemicity of Japanese encephalitis virus (JEV) in humans and animals in the Province of Bali, Indonesia, there is little data on whether seroconversion to the virus occurs in pigs, JEV genotypes circulating, and it's potential mosquito vectors in the area. The aims of this study were to (i) Determine whether JEV infection in Balinese pigs occurs before reaching their sexual maturity, (ii) identify the genotypes of circulating JEV, and (iii) identify potential JEV mosquito vectors at the study sites in urban and peri-urban areas of Bali.
Sixteen 1-week-old Landrace piglets from two different sows were housed in Denpasar. Similarly, 18 one-week-old mixed-breed piglets of two different sows were housed in Badung Regency. The piglets were bled every 1 to 4 weeks for up to 24 weeks. Serum samples from the 11 piglets were tested for antibodies against JEV, and seroconversion-suspected sera were titrated using an enzyme-linked immunosorbent assay. Blood of seroconverted sera from pigs were tested using polymerase chain reaction (PCR) to detect the genetic sequence of JEV. The mosquitoes in the sentinels were trapped throughout the study period to identify the potential mosquito vectors of JEV.
Antibodies were detected in most of the selected piglets' sera from weeks 1 to 24 of their age. However, sera of pig B9 collected from the sentinel setting in Badung Regency showed a four-fold increase in antibody titer from week 4 to week 8, indicating seroconversion. PCR testing of blood from B9 (pooled blood sample collected from week 5 to week 8) identified JEV nucleic acids, which were phylogenetically classified as belonging to the JEV genotype III. Meanwhile, 1271 of two genera of mosquitoes, spp. and spp. were trapped in the pig sentinels.
JEV seroconversion likely occurs before the pig reaches sexual maturity in Badung Regency. Sequence data indicate that JEV genotype III is circulating in the pig sentinel setting in the regency; however, circulating genotypes need to be clarified through increased surveillance. Meanwhile, spp. and most likely and spp. were the dominant mosquitoes present in the study sites set in the urban area of Denpasar and peri-urban areas of Badung, Bali, indicating that these are likely vectors in spread of JEV in the region.
尽管印度尼西亚巴厘省人和动物中存在日本脑炎病毒（JEV）地方性流行情况，但关于猪是否发生该病毒血清转化、当地流行的JEV基因型及其潜在蚊媒的数据很少。本研究的目的是：（i）确定巴厘岛猪在性成熟前是否感染JEV；（ii）鉴定流行的JEV基因型；（iii）在巴厘岛城市和城郊地区的研究地点鉴定潜在的JEV蚊媒。
来自两头不同母猪的16头1周龄长白仔猪饲养在登巴萨。同样，来自两头不同母猪的18头1周龄杂种仔猪饲养在巴东县。仔猪每1至4周采血一次，共采血24周。对11头仔猪的血清样本进行JEV抗体检测，对疑似血清转化的血清采用酶联免疫吸附试验进行滴定。对猪血清转化后的血液进行聚合酶链反应（PCR）检测，以检测JEV的基因序列。在整个研究期间诱捕哨兵猪身上的蚊子，以鉴定JEV的潜在蚊媒。
在所选仔猪1至24周龄的大多数血清样本中检测到抗体。然而，从巴东县哨兵点采集的猪B9血清在第4周和第8周抗体滴度增加了四倍，表明发生了血清转化。对B9（第5周和第8周采集的混合血样）血液进行的PCR检测鉴定出JEV核酸，系统发育分析表明其属于JEV基因型III。同时，在猪哨兵点诱捕到属于两个属的1271只蚊子，即 属和 属。
在巴东县，猪在性成熟前可能发生JEV血清转化。序列数据表明，JEV基因型III在该县的猪哨兵点流行；然而，需要通过加强监测来明确流行基因型。同时，在巴厘岛登巴萨市区和巴东县城郊地区的研究地点， 属以及很可能还有 属和 属是主要的蚊子种类，表明这些可能是该地区JEV传播的媒介。
