Streptococcus pneumoniae-associated Hemolytic Uremic Syndrome Among Children in North America

Background: To better characterize Streptococcus pneumoniae-associated hemolytic-uremic syndrome (SP-HUS), we report the largest series of SP-HUS among children in North America. Methods: We surveyed pediatric members of the Emerging Infections Network to identify SP-HUS cases. Respondents contributed clinical and laboratory features of these pediatric cases. Results: A total of 37 cases occurring between 1997 and 2009 were submitted. Of them, 33 cases (89%) were culture-confirmed and 4 (11%) were diagnosed clinically. The median patient age was 2 years, and 28 (76%) patients had completed their heptavalent pneumococcal conjugate vaccination (PCV7) series. Most patients presented with pneumonia (84%) and bacteremia (78%), whereas other clinical manifestations such as pericardial effusion (14%) and meningitis (11%) were less common. Of 29 patients, with bacteremia 6 (21%) had S. pneumoniae concurrently isolated from cerebrospinal fluid or pleural fluid. Severe illness was common with 35 (95%) patients requiring admission to the intensive care unit, over half requiring mechanical ventilation and chest tube placement or video-assisted thoracoscopic surgery, and 27 (73%) requiring dialysis during hospitalization. Among 30 patients with follow-up of 6 months, 7 (23%) remained dialysis dependent, 3 (10%) had undergone renal transplantation, 4 (13%) had neurologic sequelae, and 1 (3%) died. Among 24 serotyped isolates, 96% were non-PCV7 serotypes, most commonly 19A (50%), 92% are included in PCV13, and 10% were penicillin nonsusceptible (minimal inhibitory concentration > 2 mu g/mL). Conclusions: North American children with SP-HUS had severe clinical manifestations and significant morbidity. In this series, nearly all cases were caused by serotypes that are not in PCV7 but are included in PCV13.