Status Of Control And Prevention Of Japanese Encephalitis And Policy Recommendations Of China

Japanese encephalitis(JE), a zoonosis, is a kind of central nervous system’s acute infectious disease, due to infection with the Japanese encephalitis virus(JEV). JE is transmitted mainly during Summer and Autumn when large epidemics can occur. The main JEV transmission cycle involves Culex tritaeniorhynchus mosquitoes and similar species that lay eggs in rice paddies and other open water sources, with pigs and aquatic birds as principal vertebrate amplifying hosts. JE can occur in all ages but children are traditionally at higher risk. Infected persons(~1/250 infections) develop inflammation of the brain(encephalitis), with symptoms including high fever, coma, tremors and convulsions. Case fatality rates are 5~35%, approximately 30% of those who survive can have permanent neurologic or psychiatric sequelae, which is one of the infectious disease treating human especially children.JE usually occurs in South East Asia and part of the Western Pacific Regions. China is one of the high-incidence countries. The first reported cases were confirmed by ELISA in 1934. JE is in pandemic at the beginning of 1950 s, 1960 s and 1970 s. A total of 0.17 millon cases were reported in 1971 alone with the case fatality rate of 25%. China introduced JE into National Notifiable Disease Report and Management in 1955, JE live attenuated vaccines were licensed and went into operation in 1989, assessment of the population impact of vaccine show they are safe. The reported incidences of JE maintain below 1 per 0.1 million. JE vaccination is integrated to Expanded Program on Immunization(EPI) in 2007, the morbidity and mortality maintain at lower level. The incidences of JE are lower but with serious condition, high case fatality and more sequlae compared with other infectious disease, therefore, JE should be recognized as a public healthy priority.This study aims to do epidemiology of JE after its introduction to EPI since 2007; Review the policy of control and prevention of JE, support conditions, implementation and effectiveness evaluation to find out the weakness of strategies and implementation on JE control and prevention, then give scientific and available suggestion based on the principle of evidence-based medicine research, to further improve the policy of JE control and prevention of new period.We conduct JE cases reported through surveillance, epidemiological investigations were performed for all JE cases defined by the National Surveillance of Japanese Encephalitis during 2008~2013; The antibody levels of JE among mosquitoes and pigs were collected through surveillance; The JE vaccination data were collected from China Information Management System for Immunization Programming, and develop Lot Quality Assurance Sampling(LQAS) to evaluate JE vaccination rates; Review and analysis the policy materials, then I organized a meeting and invited experts on JE to have a discussion to give suggestion on JE control and prevention of new period.Results and Suggestions,First, the JE incidence went down in China during 2008~2013, southwest provinces are in high-prevalence. It occurs during summer and winter, attacking mainly farmers, non-resident children, adolescent and resident children, Incidence are high(>0.62 per 0.1million) in children aged 2~6 years old. However, central provinces such as Shandong and Hebei etc. were in high-incidence in 2013, and it occurs in adults aged ≥15 years old. Second, the proportion of sorts of mosquitoes varies in different province, mainly are Culex pipiens pallens and Culex tritaeniorhynchus, the density usually peaked during July to August and went down year by year. Third, the reported vaccination coverage rates are above 95%, the quick investigation showed the second dose vaccination rate are lower. Forth, China have some policies on JE control and prevention, such as the policy on JE vaccine introduction into EPI, strengthen JE cases surveillance and report, develop patriotic health campaign。1. making long-term development of a national action plan for prevention and control of JE. It should be clearly stated long-term goal of prevention and control of JE, to ensure morbidity, mortality of JE is no longer affecting public health, and even gradually eliminate JE, with the incidence decrease to 1 per million, and develop targets for different stages, identify high-prevalence provinces and its prevalence should be reduced to a certain level. Make comprehensive strategies that vaccination and avoid mosquito bites should be implemented, supplemented by a comprehensive monitoring, health education and disease prevention and control strategies.2. JE diagnosis has become a key factor restricting the accuracy of JE cases reported. JE diagnostic criteria publicizing and training should be strengthened among the medical staff to enhance awareness of diagnosis and further improve its diagnosis and treatment. Hospitals and CDCs should strengthen JE active search during JE epidemic season and supervise medical institutions to reduce false negatives. The health administrative departments at all levels should supervise and inspect the implementation of information reporting of infectious disease in medical institutions.3. carry out a comprehensive laboratory testing based acute viral encephalitis surveillance is an important supplement to improve the monitoring sensitivity of the management of JE cases. JE epidemiological and laboratory monitoring network should cover all provinces of the country as soon as possible, all above the county-level of CDC should carry encephalitis and acute viral encephalitis laboratory work, and strive to do laboratory testing of all reported cases, the needed funds should be included into the State’s Major Public Health Service Projects of national immunization programs. Strengthen the evaluation of JE trends to predict JE epidemic.4. further integrate and enhance the quality of mosquitoes and monitoring of animal hosts, which is important to strengthen JE comprehensive monitoring. Develop a sound, scientific, and a representative animal host and mosquito surveillance plan, and Funds of monitoring program should be achieved by monitor the health system requirements apply separately by patriotic central transfer payments or funds to support the inclusion of the state’s major public health service projects, including projects of national immunization programs, at the same time to strengthen the monitoring results of the analysis and use, and provide scientific basis for further adjustments to improve and refine the JE prevention and control strategies and measures.5. full implementation of national immunization programs JE vaccination is the key measures to reduce the incidence of JE. As soon as possible to study JE vaccine immunization strategy in Xinjiang, Tibet, Qinghai and the Corps. Improve Vaccination subsidies and its weight of basic public health services. Strengthen the nursery, school vaccination certificate inspection work to improve the JE vaccination two doses coverage throughout the vaccination, to further consolidate and improve routine immunization coverage of JE vaccine, ensure that all towns JE vaccination rate should reach and maintain more than 90%.6. mass vaccination in endemic areas is necessary to prevent and control of JE outbreak as a complement before the epidemic season of JE. Determine the high-prevalence counties and regularly assess JE epidemic counties, before the epidemic season, carry out a large-scale mass vaccination among high-risk population, Funds should be included in expand the national immunization program of state’s major public health special project. In non-epidemic season, annually for carry out vaccine leak finding among children under 10 years of age.7. strengthen mosquito elimination is another key measure to reduce the incidence of JE. Develop Vigorously Patriotic Health Campaign, implement environmental management based comprehensive prevention and control strategies, clear vectors breeding ground to control JE media. Combined with Patriotic Health Month, conducted mosquito elimination in livestock barns(pen) and other places to reduce mosquito density before Summer and Autumn. Take health village, town sanitation and hygiene city as the starting point, full playing the leading role of the typical model to accelerate vector control work. Take a new round of urban and rural sanitation and clean action as an opportunity to remove biological vector breeding sites, unified organize to carry out prevention and control of vector to eliminate JE.8. timely disposal of JE outbreaks. Develop encephalitis outbreak disposal, specify the definition of JE outbreak, standards, scientific guidance of JE outbreak disposal. Strengthen a patient-centered epidemic disposal, guiding the patient’s family and their neighbors immediately eradicate mosquitoes in house, cow and pig room with mosquito drugs. Amend "Pharmacopoeia of the People’s Republic of China(Edition 2010) " to carry out emergency vaccination and timely control of JE epidemic.