Analysis on the relationship between severe fever with thrombocytopenia syndrome and meteorological factors in Chaohu City based on distributed lag non-linear model
Objective To investigate the relationship between severe fever with thrombocytopenia syndrome(SFTS)and meteorological factors in Chaohu City for scientific basis for prevention and control of SFTS.Methods Daily cases of SFTS in Chaohu area from 2013 to 2022 were retrieved from the China Information System for Disease Con-trol and Prevention,and meteorological data during the same period were obtained through the Resources and Environ-mental Science Data Platform.The reference values were set based on the median of weekly average temperature(17.4℃),weekly average pressure(1 012.8 hPa),weekly sunshine duration(33.4 h)and the minimum weekly precipitation(0 mm).Then the distributed lag non-linear model(DLNM)was used to analyze the relationship between weekly SFTS cases and meteorological factors.Results In total,231 cases of SFTS were reported in Chaohu area from 2013 through 2022.The annual incidence ranged from 0.63 per 100 000 to 5.78 per 100 000 population,with an average annual inci-dence at 2.93 per 100 000,and the overall trend of the annual incidence was on the rise(Z=3.04,P<0.01).Of the report-ed cases,113 were males and 118 females,with average annual incidence being 2.90 per 100 000 and 2.97 per 100 000,respectively.By age group,the reported cases and incidence were the highest in population aged≥60 years(175 cases,10.54 per 100 000).The response curve of weekly SFTS incidence risk to weekly average temperature,weekly average pressure and sunshine duration was almost in inverted V-shape,and the response curve to weekly precipitation approxi-mately presented half U-shape.The cumulative relative risk(CRR)of SFTS was the highest when the weekly average temperature was 22.4℃[CRR=9.210,95%CI:(0.832,118.353)],and the risk of SFTS was increased when the weekly average temperature was 17.5-21.8℃(P<0.05).When the weekly average pressure was 1 015.5 hPa,the CRR of SFTS was the highest[CRR=1.877,95%CI:(0.649,5.435)].The risk of SFTS was decreased when weekly average pressure was 998.7-1 012.7 hPa and 1 022.1-1 031.5 hPa(P<0.05).The highest CRR of SFTS[CRR=1.024,95%CI:(0.882,1.188)]was seen at the sunshine duration being 31.0 h,and the risk of SFTS was decreased upon the sunshine duration being>39.3 h(P<0.05).The higher the weekly precipitation,the higher the risk of SFTS(P<0.05).Conclusions There is a nonlinear relationship between the cases of SFTS and meteorological factors.Suitable temperature and abun-dant precipitation are conducive to the occurrence of SFTS,yet high pressure and sunshine duration are unfavorable to the occurrence of SFTS.
Severe fever with thrombocytopenia syndromeMeteorological factorsDistributed lag non-linear modelChaohu City