Correlation between the positive rate of SAA in children with respiratory tract infection and ambient temperature.

The purpose of this study was to explore the application of serum amyloid A (SAA) in the outcome of upper respiratory tract infection in children by analyzing the correlation between the change of mean air temperature and the positive rate of SAA detection in children. Daily data on upper respiratory tract infection diseases and weather conditions were collected in 2016–2019. A quasi-Poisson regression with a distributed lag non-linear model was used to examine the association between temperature and SAA-positive rate. The positive rate of SAA had a moderate correlation with the temperature and a weak correlation with relative humidity. Low ambient temperature (7 °C, P1) was related to the increase in the positive rate of SAA, with the effect lag for 0–7 days (RR 1.34 (1.19~1.74)). The increase in the SAA-positive case induced by 27 °C (P75) could last for 0–14 days (RR 1.07 (1.01–1.08)), and high temperature (30 °C, P99) could reduce the positive rate of SAA. Our findings add additional evidence to the adverse effects of sub-optimal ambient temperature and provide useful information for public health programs targeting pediatric patients.