Invasive Haemophilus influenzae type b infections in children hospitalized in Hong Kong, 1986–1990

A 5‐year territory‐wide retrospective survey of invasive Haemophilus influenzae type b diseases was conducted in Hong Kong. Between 1986 and 1990, 57 cases (28 male) were recorded in children less than 12 years old (37 cases of meningitis, 9 of septicaemia and 11 of bacteraemic pneumonia). The annual incidence for children less than 5 years old was 2.7 per 105 (95% confidence interval (CI) 2.0–3.5). Of the 57 cases, 39 were Chinese and 18 non‐Chinese (7 Vietnamese refugees, 6 Caucasians, 5 others). The annual incidence in Vietnamese refugees less than 5 years old was 42.7 per 105 (95% CI 17.2–87.9), giving a relative risk of 18.5 (95% CI 8.3–41.0). Chinese patients (68%) were under‐represented as Chinese accounted for at least 94% of the population. Moreover, 14 of the 39 Chinese patients had pre‐existing medical problems, compared with only 1 of the 18 non‐Chinese patients (p= 0.022).