Trend and Disease Burden of Bacillary Dysentery in China (1991-2000)/evolution De la Dysenterie Bacillaire et Charge De Morbidite Due a Cette Maladie En Chine (1991-2000)/disenteria Bacilar: Tendencias Y Carga De Morbilidad En China (1991-2000)

Introduction Globally, morbidity and mortality due to diarrhoea has decreased from 4.6 million deaths in 1982 to 3.3 million in 1992 to 2.5 million in 2003. (1-3) A review published in 1999 reported that bacillary dysentery caused by Shigella species (S. flexneri, S. sonnei, S. boydii, and S. dysenteriae) remains a major source of diarrhoea, especially in developing countries. It also reported that of the 164.7 million episodes of shigellosis (Shigella-related diarrhoea) occurring worldwide each year, 163.2 million were in developing countries; however, the review included sparse data from China. (4) China, a developing country with the largest population in the world, has made significant socioeconomic progress over the past decade. Many indicators show that the health status of the average Chinese has improved considerably. For example, life expectancy in China increased from 57.0 years in 1957 to 71.4 years in 2000. (5) Even so diarrhoeal diseases remain an important public health problem. A cross-sectional survey conducted in 1988 estimated that of the 84 million diarrhoeal episodes that occurred in China annually, 25% affected children less than five years of age. The survey also found that Shigella is one of the principle etiologic organisms for diarrhoea. (6) A live oral Shigella vaccine which was developed and produced in China in 1997 reportedly provides 60-70% protection against S. flexneri 2a and S. sonnei infections. (7) A continuing analysis of the disease burden of bacillary dysentery would be required for effective treatment and prevention policies, health prioritization debates, and cost--benefit assessments to enable rational decisions on research, prevention and control activities. We reviewed the burden of bacillary dysentery in China with data from existing sources to determine the trends in morbidity and mortality, the high-risk populations, bacterial species, serotypes and antimicrobial resistance patterns. Methods Government statistics: national level China has two national surveillance systems for infectious diseases--the National Noticeable Infectious Disease Reporting system (NIDR) and the National Sentinel Disease Surveillance Points system (DSP). (8) The NIDR system involves all health-care facilities at the village, township, county, and city levels. The Law on the Prevention and Control of Infectious Diseases (SCSNPC, 1989) (8) requires health-care staff to report any of the 24 infectious diseases, including bacillary dysentery, to the Chinese Center for Disease Control and Prevention (CDC) where data are collected and analysed every month. The Department of Disease Control in the Ministry of Health then issues annual reports based on these data. The DSP system was started in 1978 to complement and augment the NIDR. In 1990 a stratified three-stage cluster probability sampling was designed for reselection of surveillance sites, to improve representativeness considering the variations in geographical features, inequality of economic development and the uneven health-care services in different regions of China. The system consists of 145 sites and covers around 1% of the total population of China (around 10 million people). (8-11) The representativeness of the sample was established through an index, including gross national product, literacy rate, birth rate, infant death rate, rough death rate, ratio of the age groups 0-14 years and over 65 years to the total population, ratio of labour in the industry to that in the total population, and ratio of labour in agriculture to that in the total population. (10,11) To ensure a consistent and high quality of surveillance, standard operating procedures were developed and implemented as well as training, monitoring and supervision of staff were included in this system. (11) DSP data are used to adjust national reports based on the NIDR system, which may be less complete. The World Bank has used DSP data due to its relatively high accuracy. …