Article in Japanese

A study on the epidemic season of respiratory syncytial virus infection in Sagamihara, Japan

Kiyotaka OHTANI^1,2), Hitomi INAGAKI¹⁾

Background and Purpose: In Japan, few reports have described the transition of respiratory syncytial virus (RSV) epidemic season and the relationship between RSV epidemic and weather conditions during summer.
Methods and Subjects: Between April 1, 2003 and March 31, 2018, we retrospectively studied RSV epidemic season in children hospitalized for RSV infection in our hospital. The time when the highest number of inpatients with RSV infection per month was recorded was designated as the epidemic season. RSV infection was diagnosed using commercial rapid test kits. We compared the clinical information and climatic conditions in 2017, when RSV infection was epidemic during summer and those in 2006, when it was epidemic during winter.
Results: The study included 1,026 subjects, included 587 males. The median age (interquartile range) was 8 (3–17) months. The epidemic season was believed to transition every 5 years, and many subjects were affected in summer than in winter. The clinical data of 65 subjects (32 males) studied in 2006 and 89 subjects (45 males) studied in 2017 showed that body temperature was significantly higher in 2017 than in 2006 (p = 0.02). The transition of average temperature and average humidity in both years was almost similar.
Conclusions: RSV epidemic season has been transitioning toward summer in Sagamihara. Although there were significant differences in RSV clinical information, there was no correlation with weather conditions.

---

1) Department of Pediatrics, Sagamihara Kyodo Hospital
2) Kirin Kids Allergy Clinic

Key words	respiratory syncytial virus, epidemic season, season, weather conditions, palivizumab
Received	November 22, 2018
Accepted	December 4, 2019

32 (2)：83─93,2020