Encephalitis temporally associated with live attenuated Japanese encephalitis vaccine: four case reports
- Equal contributors
1 State Key Laboratory of Pathogen and Biosecurity, Beijing Institute of Microbiology and Epidemiology, 20 Dong Da-Street, Fengtai District, Beijing 100071, People's Republic of China
2 Yunnan Institute of Parasitic Diseases, Pu'er 665000, People's Republic of China
3 Shanxi Center for Disease Control and Prevention, Taiyuan 030012, People's Republic of China
BMC Infectious Diseases 2011, 11:344 doi:10.1186/1471-2334-11-344Published: 14 December 2011
Japanese encephalitis (JE) vaccination is the most effective measure for preventing JE disease. The live attenuated JE vaccine, which has shown good efficacy and safety, has been widely used in China.
We report four laboratory-confirmed JE cases detected in JE-endemic areas during the JE virus (JEV) transmission season, who all received a first dose of live attenuated JE vaccine within 2 weeks prior to the onset of illness. All cases presented with acute encephalitis and rapidly reduced consciousness. All cerebrospinal fluid (CSF) samples from the patients were positive for JEV-specific immunoglobulin M (IgM) antibodies, but viral isolation and polymerase chain reaction (PCR) detection of JEV were both negative.
It is difficult to identify a causal link between the disease and the vaccination, as the source of positive CSF JEV IgM antibodies might be natural JEV infection or possibly due to a traumatic lumbar puncture. Our observations highlight the need for public health officers and doctors to consider reasonable vaccination policies during the JE season. In addition, continued surveillance as well as thorough investigation of any events that occur after JE vaccination is necessary.