Sex differences in incidence and fatality of severe fever with thrombocytopenia syndrome: A comparative study based on national surveillance data of China

Abstract

AbstractSevere fever with thrombocytopenia syndrome (SFTS) is a tick‐borne emerging infectious disease with an increasingly global concern. Sex difference in infectious diseases is an important public health problem. A comparative study on sex differences in SFTS incidence and fatality was conducted using all laboratory‐confirmed cases in mainland China during 2010−2018. Females had significantly higher average annual incidence rate (AAIR) with a risk ratio (RR) of 1.17 (95% confidence interval [CI] 1.11–1.22; p ˂ 0.0001), but significantly lower‐case fatality rate (CFR) with an odd ratio of 0.73 (95% CI 0.61–0.87; p = 0.001). The significant differences in AAIR and CFR were observed in age groups of 40–69 and 60–69 years, respectively (both p < 0.05). There was a rising incidence and declining CFR along with epidemic years. After adjusting for age, temporal and spatial distribution, agricultural setting and onset‐to‐diagnosis interval, the female‐to‐male difference in either AAIR or CFR remained significant. The underlying biological mechanisms of the sex‐based differences that the females are more prone to get the disease, but less likely for a fatal outcome deserve further investigations.