Study on Haemophilus influenzae type b diseases in China: the past, present and future.

Meningitis caused by Haemophilus influenzae type b (Hib) is a common and serious disease for which there now are WHO-certified vaccines that are recommended for universal infant immunization in North America and European countries. If these vaccines are to be recommended in Asia, it is necessary to know the incidence, age distribution and clinical outcome of Hib meningitis and other systemic infections in this region. Data on Hib disease in China are scanty. Hib meningitis was common during the 1950s in China, accounting for up to 16% of all of pyogenic meningitis (up to 38% of cases were caused by unknown pathogens), despite severe epidemics of meningococcal meningitis during that period. Since 1989 we have conducted hospital- and community-based etiologic and epidemiologic studies of bacterial meningitis. Hib accounts for 30 to 50% of bacterial meningitis in China. The incidence of Hib meningitis in Hefei City was 10.4 per 100000 children <5 years, a result relatively lower than in the West but higher than the rate of 2.7 found in a retrospective study in Hong Kong. Pneumonia is the primary cause of death for Chinese children. From 1991 to 1993 the average mortality of children<5 years because of pneumonia was 1563.2 per 100000. To achieve the goal of reducing the death rate of children by one-third by the year 2000, greater efforts should be made to reduce the mortality of children with pneumonia. Our preliminary study showed that about one-fourth to one-third of cases of pneumonia in Chinese children might be caused by Hib. Therefore Hib vaccination for infants and children in China might be an effective and valuable procedure to achieve the goal.