Haemophilus influenzae Serotype a as a Cause of Meningitis in Children in Brazil

Background: Since the introduction of Haemophilus influenzae type b vaccines, invasive disease due to Haemophilus influenzae serotype a (Hia) has been reported with increasing frequency. Methods: This study is based on hospital-based surveillance for Hia meningitis over a 5-year period. Results: Thirty-five patients with H. influenzae meningitis were hospitalized and 12 were serotype a. Hia was detected in blood and cerebrospinal fluid by culture or reverse transcription polymerase chain reaction. Patients' median age was 10 months, 7 (58%) boys and 5 (41%) girls. Ten (83%) children had received at least 1 vaccine dose against Haemophilus influenzae type b. All patients were treated with ceftriaxone for a median period of 11 days. The main complications described were empyema in 5 (41%) and seizures in 3 (25%) patients. Two (16.6%) patients died due to cerebral damage and shock. Conclusions: Invasive disease due to Hia affecting young children accounts for considerable morbidity and mortality.

Automated summary

This study based on hospital-based surveillance found that invasive disease due to Haemophilus influenzae serotype a (Hia) has a high morbidity and mortality rate in young children.