Epidemiological characterizations of Japanese encephalitis and its associated risk factors in Quang Ngai province, Vietnam, 2009–2017

Abstract

Background: Japanese encephalitis (JE) is one of the leading etiologies causing viral encephalitis in children in Asian and Pacific regions. The goal of this study is to determine the epidemiology characterizations of JE and Its associated risk factors in Quang Ngai province during 2009–2017. Methods and materials: A descriptive cross-sectional study combining with a prospective study of 411 cases diagnosed with viral encephalitis suspected of Japanese encephalitis (JE) and JE identified, which aim to determine epidemiology characterizations of JE and Its associated risk factors in Quang Ngai province, 2009–2017. Results: The results showed that the average incidence was 0.57/100.000 population, mortality on the incidence was 1.79%, the age group who was the most infected was under a 15-year-old group. The cases of JE lived mainly in mountainous areas with a rate of 71.4% and the plain and urban areas accounting for 28.6%. The distribution of the disease was seasonal, these cases were determined mainly during the summer months, with the peak of the epidemic in June. Among JE cases, 66% have not had a JE vaccine. The group vaccinated with three fully JE vaccines accounted for 14.3%. There is an association between the rate of fully three doses of Japanese encephalitis vaccinated and the incidence/100.000 population in Quang Ngai province. When the rate of injection of three doses of JE vaccine increases by 1%, the rate of JE determined will decrease 0.074/100.000 population with (95% CI: 2,32–12,95; p < 0,05). Conclusion: In order to reduce the incidence of Japanese encephalitis in Quang Ngai province, the national expanded immunization program organizes additional vaccination campaign for high-risk areas, groups of children who have not had enough shots for the JE vaccine and the target group of ethnic minorities in mountainous areas of Quang Ngai province.