The Frequency of Non-typeable Haemophilus influenzae Systemic Disease in Children

Abstract

95 strains of Haemophilus influenzae (H. influenzae) isolated from blood of the patients with systemic infections were serotyped by staphylococcal coagglutination during the ten years from 1992 through 2001. As a result, 92 (96.8%) cases were caused by type b strains and 3 (3.2%) cases were caused by non-typeable strains. Three cases with systemic infection due to non-typeable H. influenzae were reported. One patient was a premature neonate with sepsis and respiratory failure who had a fulminant course and died. The other two patients were a 3-year-old girl and a 1-month-old boy both with pneumonia. About their underlying conditions, one received intravenous steroid therapy and the other suffered from respiratory syncytial virus infection. They were treated with appropriate antibiotics and their clinical courses were satisfactory and uncomplicated. Non-typeable H. influenzae was isolated from not only blood but also the lower respiratory tract in all three cases. Systemic infection due to non-typeable strain is rare. But, it should be recognized as a substantial proportion of the serious infections caused by H. influenzae.