Economic and disease burden of Japanese encephalitis in Zhejiang Province, 2013–2018

Background: Japanese encephalitis (JE) is a mosquito-borne disease and associated with high mortality and disability rate among symptomatic cases. In the absence of local data, this study estimated the economic burden and the disability-adjusted life years (DALYs) due to JE in Zhejiang Province, China during 2013–2018, to increase disease awareness and provide evidence for effective health policy. Methodology/Principle findings: We merged multiple data sources, including National Notifiable Disease Registry System (NNDRS), patient interviews and medical records from corresponding hospitals for JE cases which occurred during 2013–2018 in Zhejiang Province. Direct costs were extracted from hospitals’ billing systems and patient interviews. Indirect costs and disease burden were calculated based on questionnaire survey from patient interviews and follow-up assessment by general practitioners. Given under-reporting, an expansion factor (EF) was applied to extrapolate the JE burden to the provincial level. The total economic burden of JE during 2013–2018 was estimated at US $12.01 million with an EF = 3. Of this, $8.32 million was due to direct economic cost and $3.69 million to indirect cost. The disease burden of JE was 42.75 DALYs per million population (28.44 YLD, 14.28 YLL) according to the 1990 Global Burden of Disease (GBD 1990) methodology and 80.01 DALYs (53.67YLD, 26.34YLL) according to the GBD 2010 methodology. Sensitivity analysis demonstrated that the overall economic burden varied from US$ 1.73–36.42 million. The greatest variation was due to the prognosis of illness (-85.57%-203.17%), followed by occupation (-34.07%-134.12%) and age (-72.97%-47.69%). Conclusions/Significance: JE imposes a heavy burden for families and society in Zhejiang Province. This study provides comprehensive empirical estimates of JE burden to increase awareness and strengthen knowledge of the public. These data may support provincial level public health decision making for prevention and control of JE. Ongoing surveillance for acute meningitis and encephalitis syndrome (AEMS) in sentinel hospitals, is needed to further refine estimates of JE burden. Author summary: Japanese encephalitis, an infection transmitted by mosquitos, is the most diagnosed viral encephalitis throughout Southeast Asia and the Western Pacific region. China has one of the world’s highest JE burdens. Although JE has been well-controlled in Zhejiang Province, it is associated with high mortality and disability which brings heavy burden and tremendous pain to families and society. However, specific data on costs and DALYs from the provincial level are absent. With this study, we merged multiple data sources and applied an expansion factor to estimate the total economic burden and disease burden of JE during 2013–2018 in Zhejiang Province. The total economic burden was estimated at US $12.01 million with an EF = 3. Of this, $8.32 million was due to direct economic cost and $3.69 million to indirect cost. The disease burden was 42.75 DALYs per million population according to the GBD 1990 methodology and 80.01 DALYs per million population according to the GBD 2010 methodology. The estimated data show a heavy burden of JE on the economy and health care system in Zhejiang Province. This quantification should improve awareness of health impact assessment and provide evidence for decision-making to further prevent and control JE.