Epidemiology of invasive Haemophilus influenzae type b disease in Singapore children, 1994–2003

Invasive Haemophilus influenzae type b (Hib) diseases are major causes of childhood morbidity and mortality. For the period from 1994 to 2003, we retrospectively identified 53 children with invasive Hib disease including 31 with meningitis, 14 with pneumonia, 2 with septic arthritis, 2 with epiglottitis, 1 with neutropenic sepsis, and 3 who were bacteraemic without a focus. Two children died and 22 had serious sequelae; significantly, survivors with sequelae had presented with meningitis (P-value < 0.001) or sepsis (P-value = 0.001). During the 11-year period, the annual incidence of invasive Hib disease was estimated to be 4.4/100,000 children <5 years old. With rising affluence, decreasing costs of vaccines, and increased costs in caring for survivors, universal infant immunization with Hib vaccine may need to be reconsidered in Singapore.