Adult Japanese Encephalitis Outbreak Following an Immunization Campaign in Children, Shwe Pyi Tha Village, Sittwe Township, Rakhine State, Myanmar, 2016

On 31 Aug 2016, one Japanese encephalitis (JE) case was notified from Shwe Pyi Tha Village, Sittwe Township, Rakhine State. The case was the first reported JE case from this village after implementing the single-dose JE vaccination in the area during May 2015. An outbreak investigation was conducted during September-October 2016 to confirm the outbreak and identify possible risk factors. The patient and family members were interviewed. Suspected cases were searched in the family and the village, and the medical records were reviewed. Serum samples were collected and sent for JE antibody, and dengue antigen-antibody testing. Environmental investigation, including entomological study, was conducted. The patient was a 46-year-old male worker. He got fever with headache on 14 Aug 2016. He developed convulsion and was admitted to Sittwe General Hospital with final diagnosis of viral meningitis. He was an alcoholic and usually did not sleep in a mosquito net. Active case finding among 1,758 villagers found 12 feverish villagers, including two suspected cases. Out of 11 serum samples tested, one was positive and two were equivocal for JE antibody testing. Environmental investigation revealed domestic animals, poor drainage and houses without mosquito screens. Culex tritaeniorhynchus and Culex quinquefasciatus were identified in the village as well. Considering the environmental conditions, Rakhine State should be a high priority area for routine JE immunization program. Keywords: Japanese encephalitis, outbreak, investigation, Rakhine