Background: Severe fever with thrombocytopenia (SFTS) caused by SFTS virus (SFTSV) was a tick-borne hemorrhagic fever that posed significant threat to human health in Eastern Asia. The study was designed to measure th...Background: Severe fever with thrombocytopenia (SFTS) caused by SFTS virus (SFTSV) was a tick-borne hemorrhagic fever that posed significant threat to human health in Eastern Asia. The study was designed to measure the seroprevalence of SFTSV antibody in healthy population residing in a high endemic region.Methods: A cohort study was performed on healthy residents in Shangcheng County in Xinyang City from April to December in 2018, where the highest SFTS incidence in China was reported. Anti-SFTSV IgG was measured by indirect enzyme-linked immunosorbent assay and neutralizing antibody (NAb) was detected by using PRNT50. The logistic regression models were performed to analyze the variables that were associated with seropositive rates.Results: Totally 886 individuals were recruited. The baseline seroprevalence that was tested before the epidemic season was 11.9% (70/587) for IgG and 6.8% (40/587) for NAb, which was increased to 13.4% (47/350) and 7.7% (27/350) during the epidemic season, and further to 15.8% (80/508) and 9.8% (50/508) post epidemic. The IgG antibody-based seropositivity was significantly related to the patients aged ≥ 70 years old [adjusted odds ratio (OR) = 2.440, 95% confidence interval (CI): 1.334-4.461 compared to the group of < 50 years old,P = 0.004], recent contact with cats (adjustedOR = 2.195, 95%CI: 1.261-3.818,P = 0.005), and working in tea garden (adjustedOR = 1.698, 95%CI: 1.002-2.880,P = 0.049) by applying multivariate logistic regression model. The NAb based seropositivity was similarly related to the patients aged ≥ 70 years old (adjustedOR = 2.691, 95%CI: 1.271-5.695 compared to the group of < 50 years old,P = 0.010), and recent contact with cats (OR = 2.648, 95%CI: 1.419-4.941,P = 0.002). For a cohort of individuals continually sampled with 1-year apart, the anti-SFTSV IgG were maintained at a stable level, while the NAb level reduced.Conclusions: Subclinical infection might not provide adequate immunity to protect reinfection of SFTSV, thus highlighting the ongoing threats of SFTS in endemic regions, which called for an imperative need for vaccine development. Identification of risk factors might help to target high-risk population for public health education and vaccination in the future.展开更多
基金This work was supported by the China Mega-project for Infectious Diseases(2018ZX10713002 and 2018ZX10301401)Natural Science Foundation of China(81825019 and 82073617)Peking University Medicine Fund of Fostering Young Scholars’ Scientific and Technological Innovation.
文摘Background: Severe fever with thrombocytopenia (SFTS) caused by SFTS virus (SFTSV) was a tick-borne hemorrhagic fever that posed significant threat to human health in Eastern Asia. The study was designed to measure the seroprevalence of SFTSV antibody in healthy population residing in a high endemic region.Methods: A cohort study was performed on healthy residents in Shangcheng County in Xinyang City from April to December in 2018, where the highest SFTS incidence in China was reported. Anti-SFTSV IgG was measured by indirect enzyme-linked immunosorbent assay and neutralizing antibody (NAb) was detected by using PRNT50. The logistic regression models were performed to analyze the variables that were associated with seropositive rates.Results: Totally 886 individuals were recruited. The baseline seroprevalence that was tested before the epidemic season was 11.9% (70/587) for IgG and 6.8% (40/587) for NAb, which was increased to 13.4% (47/350) and 7.7% (27/350) during the epidemic season, and further to 15.8% (80/508) and 9.8% (50/508) post epidemic. The IgG antibody-based seropositivity was significantly related to the patients aged ≥ 70 years old [adjusted odds ratio (OR) = 2.440, 95% confidence interval (CI): 1.334-4.461 compared to the group of < 50 years old,P = 0.004], recent contact with cats (adjustedOR = 2.195, 95%CI: 1.261-3.818,P = 0.005), and working in tea garden (adjustedOR = 1.698, 95%CI: 1.002-2.880,P = 0.049) by applying multivariate logistic regression model. The NAb based seropositivity was similarly related to the patients aged ≥ 70 years old (adjustedOR = 2.691, 95%CI: 1.271-5.695 compared to the group of < 50 years old,P = 0.010), and recent contact with cats (OR = 2.648, 95%CI: 1.419-4.941,P = 0.002). For a cohort of individuals continually sampled with 1-year apart, the anti-SFTSV IgG were maintained at a stable level, while the NAb level reduced.Conclusions: Subclinical infection might not provide adequate immunity to protect reinfection of SFTSV, thus highlighting the ongoing threats of SFTS in endemic regions, which called for an imperative need for vaccine development. Identification of risk factors might help to target high-risk population for public health education and vaccination in the future.
