RESUMEN
BACKGROUND: Pneumocystis is difficult to culture or detect in laboratory environments. Its ecology including the timing and method of transmission as well as environmental sources and communicability remain unclear. METHODS: We retrospectively evaluated the pattern and treatment outcome of Pneumocystis jirovecii pneumonia (PCP) in children with acute lymphoblastic leukemia (ALL) who received chemotherapy. RESULTS: A total of 56 patients with ALL were evaluated. While on chemotherapy, all patients received PCP prophylaxis. PCP were found in a total of 6 patients, including definite PCP in 2, probable PCP in 2, and possible PCP in 2 patients. There were no significant differences in sex, age group, National Cancer Institute risk group, or pneumocystis prophylaxis type between PCP and non-PCP groups. However, there was a significant statistical difference in the times of ALL diagnosis. Regarding recent chemotherapy at the time of PCP diagnosis, there were one induction, one consolidation, and four maintenance cases. All PCP patients were treated with high-dose sulfamethoxazole (100 mg/kg/day) and trimethoprim (20 mg/kg/day) intravenously. Five patients survived, while one patient with endotracheal mechanical ventilation therapy died due to respiratory failure in spite of aggressive treatment. CONCLUSION: Pediatric PCP became extremely rare due to routine prophylaxis in clinical practice of pediatric malignancy. Nevertheless, we analyzed patients with acute lymphoblastic leukemia who had received PCP prophylaxis for 14 years, and analyzed the clustered outbreaks of PCP. It is still important to emphasize the need for prophylaxis and to increase the level of attention and isolation under environmental and personal risk factors.