Trends and factors associated with invasive non-typeable and serotype B Haemophilus influenzae disease in persons of all ages in South Africa from 2003-2009

Abstract

Haemophilus influenzae type b disease (Hib) was a major cause of childhood disease but has nearly been eliminated in developed countries after the introduction of Hib conjugate vaccine. An increase in non-typeable H. influenzae (NTHi) disease was observed in some countries post-Hib vaccination which prompted concerns about possible serotype replacement. Hib disease in children <5 years of age decreased by a minimum estimate of 71% in South Africa after the Hib vaccine introduction in 1999. The epidemiology of Hib disease among persons >5 year olds and NTHi disease in all ages has not been described in South Africa before. The aim of this study is therefore to describe the trends and factors associated with invasive Hib and NTHi disease in South Africa, 2003-2009 among persons of all ages.