Pneumocystis Infection in Children: National Trends and Characteristics in the United States, 1997–2012

Abstract

Background: Although the epidemiology of immunocompromising condition in children has evolved over time, updated epidemiology of pediatric pneumocystis infection in the United States is not available. Methods: We performed a retrospective analysis using the Kids’ Inpatient Database, a nationally representative sample of US pediatric hospital discharges collected in 1997, 2000, 2003, 2006, 2009 and 2012. Pneumocystis cases were identified using International Classification of Diseases, Ninth Revision, Clinical Modification, code 136.3 among children 0–18 years of age. Demographic data of cases with and without mortality were compared. Results: We identified 1902 [standard error (SE): 95] pneumocystis cases during the study period. The pneumocystis hospitalization rate decreased from 7.5 (SE: 0.91) to 2.7 (SE: 0.31) per a million US children from 1997 to 2012 (63.2% decrease). Cases with HIV infection decreased from 285 (SE: 56) cases in 1997 to 29 (SE: 7) cases in 2012, whereas hematologic malignancy and primary immunodeficiency became more prominent. Infants were the most commonly affected [510 cases (SE: 40)]. All-cause in-hospital mortality was 11.7% (SE: 1.3%) and was particularly high among cases with hematopoietic stem cell transplant [32.4%(SE: 7.1%); P < 0.001]. Conclusions: Pneumocystis infection in children showed a marked decrease from 1997 to 2012 in the United States, largely driven by the reduction in HIV-associated cases, and cases with non-HIV illnesses became more prominent. Hematopoietic stem cell transplant–associated cases had particularly high mortality. Clinicians should be aware of high-risk groups that may benefit from chemoprophylaxis, particularly in infancy.