Director of Pediatrics Iizuka hospital Iizuka, Fukuoka, Japan
Background: Since public health measures against COVID-19 were relaxed, outbreaks of various infectious diseases have been reported around the world, including in Japan. In the United States, the number of cases in 2024 was more than five times higher than during the same period in 2023, and exceeded the number reported before the COVID-19 pandemic in 2019. Reports from Asia have indicated that the proportion of patients in late childhood to adolescence ranges from 66.8% to 87%. As of May 2025, the cumulative number of reported pertussis cases in our country had reached 22,351, rapidly increasing to more than five times the total for all of 2024. Of these, teenagers account for 58.7%. Objective: Summarize the clinical course of pediatric patients with pertussis who were hospitalized at our institution. Design/Methods: We retrospectively extracted information from medical records on the hospitalization period, history of mechanical ventilation, and vaccination status for 30 patients hospitalized between January 2011 and August 2025. Results: Among them, 13 were boys and 17 were girls. The median age at admission was 0 years (range 0–11 years). Of the 25 infants aged 0 years, 80% were less than 2 months old. Specifically, 2 were 0 months old, 10 were 1 month old, and 8 were 2 months old. All four patients aged 6 or older were hospitalized in 2025. Up to 2024, the median number of hospitalizations per year was one (range 0–3), but between January and August 2025, this number surged to 14. All 10 patients who experienced apnea were 0 years old. One infant received oxygen therapy, and six required mechanical ventilation. There were no deaths; all patients were discharged, although one patient had prolonged apnea attacks and required home oxygen therapy. At the time of admission, there was no significant tendency for higher white blood cell counts or peripheral blood lymphocyte counts in patients with apnea or those who required mechanical ventilation. Of the 26 patients with recorded vaccination history, the 19 unvaccinated patients had significantly longer hospital stays than those who had been vaccinated.
Conclusion(s): There are reports of the emergence of macrolide-resistant strains, which may be involved in pertussis. This season’s pertussis tends to be more severe, especially in infants who have not yet started vaccination, and places a heavy burden on the PICU. In response to the high number of school-aged pertussis cases, the National Disease Prevention and Control Administration of China decided to change the DT vaccine administered at age 6 to the DPT vaccine. This is also good idea for our country.
Trends in the number of hospitalized patients. figure 1.pdfUp to 2024, the median number of hospitalizations per year was one (range 0–3), but between January and August 2025, this number surged to 14.
