Abstract：
BACKGROUND: Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne infectious disease caused by the SFTS virus (SFTSV). The Miyazaki Prefecture has the highest number of SFTS cases in Japan and requires countermeasures for prevention. In this study, we aimed to conduct an epidemiological survey in Miyazaki Prefecture to determine the exposure conditions of SFTSV by measuring the seroprevalence among residents of Miyazaki and to evaluate the factors that influence the endemicity of SFTS.
METHODS: The survey was conducted between June 2014 and April 2019 in all 26 municipalities in Miyazaki Prefecture. SFTSV antibodies were detected using an enzyme-linked immunosorbent assay in the blood samples of 6013 residents (3184 men and 2829 women). A questionnaire-based survey of the living environment was also conducted.
RESULTS: Multiple logistic regression analysis revealed that age and occupation were significant factors related to the proportion of participants with an optical density (OD) value > 0.2 and a seroprevalence of 0.9 % (54/6013). Seven seropositive individuals (0.1 %) with an OD value of >0.4 were identified (three men and four women, aged 54-69 years), and all were asymptomatic. One participant had a higher OD than the positive control.
CONCLUSIONS: Although SFTS is endemic in Miyazaki Prefecture, Japan, its seroprevalence is relatively low. Since some risk areas in Miyazaki prefecture have been identified, it is important to enhance awareness of SFTS in residences and reduce contact with ticks, especially in high-risk areas.
METHODS: The survey was conducted between June 2014 and April 2019 in all 26 municipalities in Miyazaki Prefecture. SFTSV antibodies were detected using an enzyme-linked immunosorbent assay in the blood samples of 6013 residents (3184 men and 2829 women). A questionnaire-based survey of the living environment was also conducted.
RESULTS: Multiple logistic regression analysis revealed that age and occupation were significant factors related to the proportion of participants with an optical density (OD) value > 0.2 and a seroprevalence of 0.9 % (54/6013). Seven seropositive individuals (0.1 %) with an OD value of >0.4 were identified (three men and four women, aged 54-69 years), and all were asymptomatic. One participant had a higher OD than the positive control.
CONCLUSIONS: Although SFTS is endemic in Miyazaki Prefecture, Japan, its seroprevalence is relatively low. Since some risk areas in Miyazaki prefecture have been identified, it is important to enhance awareness of SFTS in residences and reduce contact with ticks, especially in high-risk areas.
摘要：
背景：严重发热伴血小板减少综合征（SFTS）是由SFTS病毒（SFTSV）引起的蜱传传染病。宫崎县是日本SFTS病例最多的地区，需要采取预防对策。在这项研究中,我们旨在在宫崎县进行流行病学调查,通过测量宫崎县居民血清阳性率来确定SFTSV的暴露条件,并评估影响SFTS地方性的因素.
方法：该调查于2014年6月至2019年4月在宫崎县的所有26个城市进行。使用酶联免疫吸附测定法在6013名居民（3184名男性和2829名女性）的血液样本中检测到SFTSV抗体。还对居住环境进行了问卷调查。
结果：多元逻辑回归分析显示，年龄和职业是与光密度（OD）值>0.2且血清阳性率为0.9％的参与者比例相关的重要因素（54/6013）。确定了7名血清阳性个体（0.1％），OD值>0.4（3名男性和4名女性，54-69岁)，都是无症状的.一个参与者的OD高于阳性对照。
结论：尽管SFTS在宫崎县是地方性的，Japan,其血清阳性率相对较低。由于宫崎县的一些危险区域已经确定,重要的是要提高住宅对SFTS的认识，减少与蜱的接触，特别是在高风险地区。
方法：该调查于2014年6月至2019年4月在宫崎县的所有26个城市进行。使用酶联免疫吸附测定法在6013名居民（3184名男性和2829名女性）的血液样本中检测到SFTSV抗体。还对居住环境进行了问卷调查。
结果：多元逻辑回归分析显示，年龄和职业是与光密度（OD）值>0.2且血清阳性率为0.9％的参与者比例相关的重要因素（54/6013）。确定了7名血清阳性个体（0.1％），OD值>0.4（3名男性和4名女性，54-69岁)，都是无症状的.一个参与者的OD高于阳性对照。
结论：尽管SFTS在宫崎县是地方性的，Japan,其血清阳性率相对较低。由于宫崎县的一些危险区域已经确定,重要的是要提高住宅对SFTS的认识，减少与蜱的接触，特别是在高风险地区。
