Ladreyt Héléna, Auerswald Heidi, Tum Sothyra, Ken Sreymom, Heng Leangyi, In Saraden, Lay Sokchea, Top Chakriyouth, Ly Sowath, Duong Veasna, Dussart Philippe, Durand Benoit, Chevalier Véronique
Epidemiology Unit, Laboratory for Animal Health, French Agency for Food, Environmental and Occupational Health and Safety (ANSES), University Paris-Est, 14 rue Pierre et Marie Curie, 94700 Maisons-Alfort, France.
International Center of Research in Agriculture for Development (CIRAD), UMR ASTRE, F-34090 Montpellier, France.
Pathogens. 2020 Sep 1;9(9):719. doi: 10.3390/pathogens9090719.
Japanese encephalitis virus (JEV) is the main cause of human viral encephalitis in Asia, with a mortality rate reaching 30%, mostly affecting children. The traditionally described cycle involving wild birds as reservoirs, pigs as amplifying hosts and mosquitoes as vectors is questioned, with increasing evidence of a more complex multi-host system involved in areas where densities of pigs are low, such as in Cambodia. In 2018, we examined pigs, chickens, ducks and dogs from Kandal province, Cambodia, for antibody response against JEV by hemagglutination inhibition and virus neutralization assays. Forces of infection (FOI) for flaviviruses and JEV were estimated per species and per unit of body surface area (BSA). JEV seroprevalence reached 31% (95% CI: 23-41%) in pigs, 1% (95% CI: 0.1-3%) in chickens, 12% (95% CI: 7-19%) in ducks and 35% (95% CI: 28-42%) in dogs. Pigs were most likely to be infected (FOI: 0.09 per month), but the FOI was higher in ducks than in pigs for a given BSA (ratio of 0.13). Dogs had a lower FOI than ducks but a higher FOI than chickens (0.01 per month). For a given BSA, dogs were less likely to be infected than pigs (ratio of 1.9). In Cambodia, the virus may be circulating between multiple hosts. Dogs live in close contact with humans, and estimating their exposure to JEV infection could be a relevant indicator of the risk for humans to get infected, which is poorly known due to underdiagnosis. Understanding the JEV cycle and developing tools to quantify the exposure of humans is essential to adapt and support control measures for this vaccine-preventable disease.
日本脑炎病毒（JEV）是亚洲人类病毒性脑炎的主要病因，死亡率达30%，主要影响儿童。传统描述的以野生鸟类为储存宿主、猪为扩增宿主、蚊子为传播媒介的循环受到质疑，越来越多的证据表明，在猪密度较低的地区，如柬埔寨，存在更复杂的多宿主系统。2018年，我们通过血凝抑制试验和病毒中和试验，检测了柬埔寨干丹省的猪、鸡、鸭和狗对JEV的抗体反应。按物种和每单位体表面积（BSA）估算了黄病毒和JEV的感染力（FOI）。猪的JEV血清阳性率达31%（95%置信区间：23 - 41%），鸡为1%（95%置信区间：0.1 - 3%），鸭为12%（95%置信区间：7 - 19%），狗为35%（95%置信区间：28 - 42%）。猪最易感染（FOI：每月0.09），但对于给定的BSA，鸭的FOI高于猪（比率为0.13）。狗的FOI低于鸭但高于鸡（每月0.01）。对于给定的BSA，狗比猪更不易感染（比率为1.9）。在柬埔寨，该病毒可能在多个宿主之间循环。狗与人类密切接触，估计它们接触JEV感染的情况可能是人类感染风险的一个相关指标，由于诊断不足，这方面情况鲜为人知。了解JEV循环并开发量化人类接触情况的工具，对于调整和支持针对这种可通过疫苗预防疾病的控制措施至关重要。
