Outbreak of Common Cold Caused by Rhinovirus A in an Elementary School Suwannaphum District, Roi Et Province, 26 May-30 June 2024

Abstract

On June 18, 2024, the Situation awareness team from the Roi Et provincial public health office received a report from the epidemiology unit of Suwannaphum hospital regarding a cluster of 20 students exhibiting influenza-like symptoms. An outbreak investigation was conducted from May 26 to June 30, 2024, aiming to confirm the diagnosis and outbreak, identify the cause and risk factors, and implement disease control measures. A retrospective cohort study was employed, using multiple logistic regression analysis. The study population included 1,670 students and school personnel. A total of 338 cases met the case definition, with an attack rate of 20.23%. The majority were female (n=200, 48.09%), aged 9–12 years (mean age = 10). The highest attack rate occurred in the fourth-grade classroom (95.65%). Common symptoms included nasal discharge (76.63%), cough (73.08%), and sore throat (28.11%). The initial onset was on June 1, 2024, with the outbreak peaking from June 11–20, 2024. Environmental assessment revealed 12 school buildings with both air-conditioned and fan-cooled rooms, shared water dispensers in cafeterias, and separate male and female restrooms. Laboratory testing of 13 samples confirmed 4 cases of rhinovirus (RV34) and 1 case of influenza A (H1N1). Significant risk factors included close contact with infected individuals (OR adj. = 6.85, 95% CI: 3.17–14.78), drinking water from classroom dispensers (OR adj. = 6.32, 95% CI: 3.56–11.23) and cafeteria dispensers (OR adj. = 10.04, 95% CI: 5.27–19.14), sharing personal items (OR adj. = 8.66, 95% CI: 2.99–25.01), having pre-existing conditions (OR adj. = 9.06, 95% CI: 0.41–17.97), not wearing face masks (OR adj. = 2.79, 95% CI: 1.63–4.78), and sharing drinking glasses (OR adj. = 2.02, 95% CI: 1.26–3.23). A protective factor was drinking from personal bottled water (OR adj. = 0.38, 95% CI: 0.32–0.45). Recommendations include reducing close contact, consistent mask usage particularly among those with chronic conditions such as asthma avoiding shared personal items, and promoting the use of personal bottled water to prevent influenza transmission.