Correlation of respiratory syncytial virus infection with climate parameters and air pollution levels in Korean children during 2005–2012

ABSTRACT

PURPOSE: Respiratory syncytial virus (RSV) is the major cause of acute lower respiratory tract infection (LRTI) in infants and children. We investigated the association of meteorological conditions and air pollution with the prevalence of RSV infection. METHODS: Between January 2005 and December 2012, a total of 9,113 nasopharyngeal swab specimens from children under 3 years of age who were admitted to the hospital with acute LRTI were tested for RSV antigens using a direct immunofluorescence kit. Meteorological data (mean temperature, precipitation, wind speed, and relative humidity) and air pollutant levels including PM₁₀ (particulate matter with a median aerodynamic diameter less than or equal to 10 µm in diameter), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and carbon monoxide (CO) in Seoul during the study period were collected from the national monitoring system. The correlations of the monthly incidence of RSV infection with climate factors and air pollutant levels were analyzed. RESULTS: RSV infection mainly occurred between October and February, and showed the peak in November. The prevalence of RSV infection had a moderate negative correlation with mean temperature (r=−0.60, P < 0.001), a weak negative correlation with relative humidity (r=−0.26, P=0.01), and precipitation (r=−0.34, P=0.001). Regarding air pollutants, RSV activity moderately correlated with NO₂ (r=0.40, P < 0.001), SO₂ (r=0.41, P < 0.001), and CO (r=0.58, P < 0.001). In the RSV peak season in Korea (between October and February), RSV epidemics showed a weak positive correlation with relative humidity (r=0.35, P=0.03) and precipitation (r=0.38, P=0.02). CONCLUSION: Meteorological factors and air pollutant levels may be associated with RSV activity. Therefore, further nationwide large-scaled intensive evaluations to prove factors affecting RSV activity are warranted.