Detection of Pneumocystis Jirovecii in Immunocompetent Children with Lower Respiratory Tract Infection

Few studies have been conducted on Pneumocystis jirovecii infection in immunocompetent children with respiratory symptoms, and co-infection patterns are limited. This study aimed to describe the detection of Pneumocystis jirovecii by targeted next-generation sequencing (tNGS) in immunocompetent children with lower respiratory tract infection (LRTI) and compare co-infection patterns.

From March through July 2023, 117 immunocompetent children with LRTI underwent bronchoalveolar lavage fluid (BALF) testing via tNGS at the Maternal and Child Health Hospital in Meizhou (Guangdong, China). The prevalence of Pneumocystis jirovecii and co-infection with other pathogens were analyzed.

Respiratory pathogens were identified in 114 children (97.4%), and Pneumocystis jirovecii was detected in 18 (15.4%). The median age of the Pneumocystis jirovecii positive group was significantly younger than that of the negative group (0.8 vs. 3.9 years, p = 0.008). Co-infections with Pneumocystis jiroveci were common, but only cytomegalovirus and human respiratory syncytial virus showed a positive correlation and Mycoplasmoides pneumoniae showed a negative correlation. Two out of three children treated with trimethoprimsulfamethoxazole and fifteen children with no specific therapy recovered well from clinical and radiological signs. Literature review showed that Pneumocystis jirovecii was relatively common in immunocompetent children with respiratory symptoms (0.8% to 32.4%).

The clinical significance of detection of Pneumocystis jiroveci in immunocompetent children with LRTI should be further investigated, and specific therapy could be considered individually based on clinical symptoms, radiological features, and co-infection patterns.