Abstract:

Objective To raise the awareness of Pneumocystis jirovecii pneumonia (PCP) in children complicated with severe pertussis, and to enable early diagnosis for improved prognosis. Methods The clinical data of children diagnosed with severe pertussis complicated by PCP from January 1, 2020 to December 31, 2023 were retrospectively analyzed. Results Five cases were enrolled, with one male and four females. The median age was 3.0(2.5-10.0) months, and the median hospital stay was 17.0(7.5-23.5) days, with three deaths recorded. All cases experienced apnea and hypoxemia, with 3 cases presented acute respiratory distress syndrome (ARDS), and 3 cases developed pulmonary hypertension and pertussis encephalopathy. The peak of leucocyte count were 43.8(25.2-87.8)×10⁹/L, which decreased to a post-treatment median of 8.5(5.0-36.5)×10⁹/L, and the median LDH was 942.0(466.5-1837.0) U/L. All 5 cases were treated with azithromycin before diagnosis of PCP, and co-trimoxazole combined with echinocandin were administered additionally for PCP, while 2 survivors were treated within 5 days. Conclusion PCP can occur in severe pertussis children without immunodeficiency, and there is a high risk of death when severe pertussis is complicated by PCP. When the routine treatment for severe pertussis in children has poor efficacy, it is necessary to be alert for Pneumocystis jirovecii infection. Early combined use of co-trimoxazole with echinocandin may improve prognosis.

Key words: severe pertussis, Pneumocystis jirovecii pneumonia, Pneumocystis jirovecii, child