Pneumocystis jirovecii pneumonia in children. A retrospective study in a single center over three decades

Area of Science:

• Pediatric Infectious Diseases
• Immunocompromised Hosts
• Respiratory Medicine

Background:

• Pneumocystis jirovecii pneumonia (PJP) is a life-threatening opportunistic infection.
• It primarily affects immunocompromised individuals, particularly children.
• Understanding PJP epidemiology and clinical features in pediatric populations is crucial for improving outcomes.

Purpose of the Study:

• To analyze the epidemiologic and clinical characteristics of PJP cases in pediatric patients.
• To describe the prognosis and identify risk factors associated with PJP in this population.
• To evaluate trends in PJP diagnosis and outcomes in the context of evolving medical treatments.

Main Methods:

• Retrospective study of pediatric patients (≤18 years) diagnosed with PJP between January 1989 and December 2016.
• Case definition included acute pneumonitis with P. jirovecii detection via bronchoalveolar lavage or tracheal aspirate.
• Diagnostic methods encompassed methenamine silver staining, direct antibody fluorescence, and Real-Time Polymerase Chain Reaction.

Main Results:

• Twenty-five PJP cases were identified over the study period (0.9 cases/year).
• The median age was 2.2 years, with 64% males; 12% received antimicrobial prophylaxis.
• Mortality was 20% overall, with worse outcomes in HIV-non-infected children and those requiring steroids. Risk factors for PICU admission included being HIV-non-infected, higher LDH, younger age, and shorter time to PJP diagnosis.

Conclusions:

• PJP is now predominantly diagnosed in HIV-non-infected children at this institution, coinciding with widespread antiretroviral therapy use.
• HIV-non-infected pediatric patients with PJP exhibit significantly higher morbidity rates.
• This shift necessitates targeted prevention and management strategies for PJP in non-HIV-infected immunocompromised children.