Henriksson Ellinor, Söderberg Rebecca, Ström Hallenberg Gunilla, Kroesna Kang, Ly Sokong, Sear Borin, Unger Fred, Tum Sothyra, Nguyen-Viet Hung, Lindahl Johanna F
Department of Clinical Sciences, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden.
Public Health Agency Sweden, 171 65 Stockholm, Sweden.
Pathogens. 2021 May 10;10(5):578. doi: 10.3390/pathogens10050578.
Japanese encephalitis (JE) is endemic in Cambodia, but circulation of JE virus (JEV) among domestic pigs has previously only been studied in the southern part of the country. The main purpose of this study was to determine the seroprevalence of JEV antibodies in smallholder pigs held in rural areas of Kampong Thom, Preah Vihear, Ratanakiri, and Stung Treng provinces, northeastern Cambodia. Another purpose was to identify possible associations between serologic status and other factors, such as reproductive disorders, and to investigate the farmers' knowledge of mosquito-borne diseases and use of preventive measures. In October 2019, 139 households were visited throughout the study area, and 242 pigs were sampled for blood. The sera were analysed with ELISA for JEV antibodies. Household representatives were interviewed, and data were recorded for each sampled pig. The apparent seroprevalence was 89.1% in pigs between 3 and 6 months of age, and 100% in pigs over 6 months of age. In total, 93.0% of the pigs tested positive. Province appeared to be the only factor significantly associated with serologic status ( < 0.001). Almost all (97.8%) respondents knew that mosquitos could transmit diseases, and 70.5% had heard of JE. However, only one respondent knew that JEV is transmitted to people through mosquito bites. Very few respondents knew that pigs can become infected with JEV, and no one knew that mosquitos transmit the virus. All families used some sort of mosquito protection for themselves, but only 15.1% protected their pigs from mosquito bites. The children were vaccinated against JE in 93 households, while adults only were vaccinated in eight households. The results suggest that JEV transmission is intense in northeastern Cambodia, and that people's knowledge about the transmission route of JEV and the role of pigs in the transmission cycle is low. Fortunately, people are well aware of mosquito-borne diseases in general and use mosquito protection, and many children are vaccinated against JE. Nonetheless, it is important that national vaccination is continued, and that people-especially in rural areas where pigs are commonly kept-are educated on the ecology and transmission of JEV.
日本脑炎（JE）在柬埔寨呈地方流行，但此前仅对该国南部地区家猪中的日本脑炎病毒（JEV）传播情况进行过研究。本研究的主要目的是确定柬埔寨东北部磅通、柏威夏、拉塔纳基里和上丁省农村地区小农户饲养的家猪中JEV抗体的血清阳性率。另一个目的是确定血清学状态与其他因素（如生殖障碍）之间可能存在的关联，并调查农民对蚊媒疾病的了解情况以及预防措施的使用情况。2019年10月，在整个研究区域走访了139户家庭，采集了242头猪的血液样本。采用酶联免疫吸附测定法（ELISA）分析血清中的JEV抗体。与每户家庭代表进行了访谈，并记录了每头采样猪的数据。3至6月龄猪的表观血清阳性率为89.1%，6月龄以上猪的表观血清阳性率为100%。总体而言，93.0%的猪检测呈阳性。省份似乎是与血清学状态显著相关的唯一因素（<0.001）。几乎所有（97.8%）受访者都知道蚊子可以传播疾病，70.5%的人听说过日本脑炎。然而，只有一名受访者知道JEV是通过蚊虫叮咬传播给人类的。很少有受访者知道猪会感染JEV，没有人知道蚊子会传播这种病毒。所有家庭都对自己采取了某种防蚊措施，但只有15.1%的家庭保护其猪免受蚊虫叮咬。93户家庭的儿童接种了日本脑炎疫苗，只有8户家庭的成年人接种了疫苗。结果表明，柬埔寨东北部JEV传播活跃，人们对JEV传播途径以及猪在传播循环中的作用了解不足。幸运的是，人们普遍对蚊媒疾病有充分认识并采取了防蚊措施，许多儿童接种了日本脑炎疫苗。尽管如此，继续开展全国性疫苗接种以及对人们（尤其是在普遍养猪的农村地区）进行JEV生态学和传播方面的教育仍然很重要。
