ABSTRACT
Objective·To examine the seasonality of post-traumatic wound infection (PWI) and surgery site infection (SSI) from the perspectives of occurrence and microbiological distribution.Methods·The cumulative incidences of PWI and SSI in different seasons were respectively calculated and compared in a cohort of 2 177 patients who sustained open-wounded injuries in the upper or lower extremity and a cohort of 11 809 patients receiving selective orthopedic operation from 2013 to 2015 in Shanghai Sixth People's Hospital.Multifactorial linear regression was used to measure the influence of meteorological parameters on PWI incidence.Moreover,the microbiological distribution of PWI and SSI was analyzed on a seasonal basis.Results·The incidence of PWI in the patients was 2.20％ from 2013 to 2015,and there were significant seasonal patterns (1.04％ in spring,3.52％ in summer,3.10％ in autumn,0.71％ in winter,P=0.004).The incidence of SSI was 0.21％,and there was no seasonal difference (P=0.809).Only average temperature (P=0.002,β=0.016) was correlated with the occurrence of PWI in multifactorial linear regression analysis.Microbiological analysis revealed the dominance of Gram-negative bacteria in SSI cases during the summer and autumn (P=0.021).However,this trend was not observed in PWI cases (P=0.694).Conclusion·There is a seasonal pattern in PWI occurrence with peaks in summer and auturrm,which is correlated with temperature.There is no seasonal difference in SSI incidence,but SSI cases were dominantly infected by Gram-negative bacteria in summer and autumn.