Bacterial meningitis among children under the age of 2 years in a high human immunodeficiency virus prevalence area after Haemophilus influenzae type b vaccine introduction

Abstract

The aim of this study was to describe bacterial causes of meningitis among children < 2 years in a high human immunodeficiency virus (HIV) prevalence area after introduction of routine Haemophilus influenzae type b vaccination. Data collected between April 2003 and December 2008 were extracted from a surveillance database and medical records of children < 2 years admitted in Mbarara Hospital, Uganda with suspected bacterial meningitis. HIV infection was confirmed using rapid tests and polymerase chain reaction and bacterial meningitis by using cerebrospinal fluid culture. Between April 2003 and December 2008, 1464 children under 5 years were admitted with suspected bacterial meningitis of which 1235 (84.4%) had cerebrospinal fluid collected; 894 (72.4%) of these samples were from children < 2 years. Of the 894 samples, 64 (7.2%) grew an organism including Streptococcus pneumoniae (26; 41%), Salmonella species (20; 31%), H. influenzae (6; 9%) and coliforms (7; 11%), and five (8%) grew contaminants that are all coagulase negative Staphylococcus. Of the 894 children, 468 (52.3%) were tested for HIV; 16.7% were positive. Fifty-one children had a pathogenic isolate and a treatment outcome, and 23 (45%) died; 13 (56.6%) deaths were due to S. pneumoniae, eight (34.8%) were due to Salmonella spp., one (4.3%) was due to H. influenzae and one (4.3%) was due to coliforms. HIV infection was associated with a threefold increase in mortality, increased likelihood of a bacterial isolate and decreased likelihood of malaria parasitaemia. Following H. influenzae type b vaccine introduction, S. pneumoniae and Salmonella spp. are the major causes of bacterial meningitis among children < 2 years in Uganda. Pneumococcal conjugate vaccines and reduction in mother to child transmission of HIV could reduce the observed mortality.