An outbreak of Japanese encephalitis in elderly people in Baotou, Inner Mongolia, 2018

ObjectiveTo investigate an outbreak of Japanese encephalitis（JE）in elderly people in Tuyou district of Baotou in Inner Mongolia in 2018 and provide scientific evidence for the standardized response to such events in the future.

MethodsCase investigation was conducted for all cases, and the blood and cerebrospinal fluid samples of patients were used for the detection of JE virus nucleic acid with PCR and the samples from some villagers and domestic pigs were collected for the detection of JE virus antibody with ELISA.

ResultsThe outbreak occurred in August and 5 cases were reported, including 2 deaths. The cases were elderly people in rural areas with underlying diseases and without immunization histories of JE vaccine. In the 5 cases, the serum and cerebrospinal fluid samples were negative for JE virus nucleic acid and positive for IgM antibody, while the serum samples of 5 villagers and 2 domestic pigs were IgM positive, and 108 serum samples of villagers were IgG positive.

ConclusionThe investigation confirmed that an outbreak of JE occurred in elderly people in Tuyou district of Baotou in 2018, and infection of JE virus was detected in local people and pigs. The surveillance for JE and mosquito vector should be strengthened in the future.