Need for Haemophilus influenzae type b vaccination in Asia as evidenced by epidemiology of bacterial meningitis

To evaluate the role of Haemophilus influenzae type b (Hib) infections in Asia by scrutinizing data on Hib meningitis.

A comprehensive literature search was performed in English and other languages. Special attention was paid to the age group of 0 to 4 years, in which the great majority of Hib meningitis occurs.

Twenty studies from as many countries indicated Hib to be a major pathogen in childhood meningitis. In series comprising nearly 2000 patients, Hib was responsible for at least 50% of cases in one-third of series and for at least 25% in three-fourths of series investigated and was the leading pathogen overall. The countries in South and Southeast Asia differed from the Middle East and East Asia in having a greater incidence of meningitis during the first 6 months of life; the proportions were 50 to 60% vs. 10 to 30%, respectively (P < 0.001).

Despite lacking data from many areas, belief in a paucity of Hib disease in Asia is not supported by the existing data; and because meningitis represents only 50 to 75% of all classical Hib manifestations and some cases occur after the age of 4 years, vaccination is warranted. The cumulative age curves suggest that conjugates with good immunogenic potential should be used, especially in South and Southeast Asia.