Epidemiology of acute lower respiratory tract infections, especially those due to Haemophilus influenzae type b, in The Gambia, west Africa.

Mortality surveys undertaken in rural areas of The Gambia, a small country on the west coast of Africa, indicate that acute lower respiratory tract infections (ALRI) are the most frequent cause of death among children and that approximately 1 in 25 rural Gambian children dies from an ALRI before the age of 5 years. Community surveys suggest that each child experiences an average of one episode of ALRI accompanied by radiographic changes before reaching this age. Etiologic studies have shown that pneumococci, Haemophilus influenzae type b (Hib), and respiratory syncytial virus are the most important causes of ALRI in Gambian children who present to a hospital, and the same three organisms are probably the major causes of severe ALRI in rural communities. Hib probably accounts for 5%-10% of cases of severe ALRI in Gambian children, and because the incidence of severe ALRI is high, an effective Hib conjugate vaccine might save as many childhood deaths by preventing pneumonia as by preventing meningitis.