Abstract：
OBJECTIVE: To investigate the distribution and prevalence of Japanese encephalitis virus (JEV) antibody (as evidence of past infection) in northern Victoria following the 2022 Japanese encephalitis outbreak, seeking to identify groups of people at particular risk of infection; to investigate the distribution and prevalence of antibodies to two related flaviviruses, Murray Valley encephalitis virus (MVEV) and West Nile virus Kunjin subtype (KUNV).
METHODS: Cross-sectional serosurvey (part of a national JEV serosurveillance program).
METHODS: Three northern Victorian local public health units (Ovens Murray, Goulburn Valley, Loddon Mallee), 8 August - 1 December 2022.
METHODS: People opportunistically recruited at pathology collection centres and by targeted recruitment through community outreach and advertisements. People vaccinated against or who had been diagnosed with Japanese encephalitis were ineligible for participation, as were those born in countries where JEV is endemic.
METHODS: Seroprevalence of JEV IgG antibody, overall and by selected factors of interest (occupations, water body exposure, recreational activities and locations, exposure to animals, protective measures).
RESULTS: 813 participants were recruited (median age, 59 years [interquartile range, 42-69 years]; 496 female [61%]); 27 were JEV IgG-seropositive (3.3%; 95% confidence interval [CI], 2.2-4.8%) (median age, 73 years [interquartile range, 63-78 years]; 13 female [48%]); none were IgM-seropositive. JEV IgG-seropositive participants were identified at all recruitment locations, including those without identified cases of Japanese encephalitis. The only risk factors associated with JEV IgG-seropositivity were age (per year: prevalence odds ratio [POR], 1.07; 95% CI, 1.03-1.10) and exposure to feral pigs (POR, 21; 95% CI, 1.7-190). The seroprevalence of antibody to MVEV was 3.0% (95% CI, 1.9-4.5%; 23 of 760 participants), and of KUNV antibody 3.3% (95% CI, 2.1-4.8%; 25 of 761).
CONCLUSIONS: People living in northern Victoria are vulnerable to future JEV infection, but few risk factors are consistently associated with infection. Additional prevention strategies, including expanding vaccine eligibility, may be required to protect people in this region from Japanese encephalitis.
METHODS: Cross-sectional serosurvey (part of a national JEV serosurveillance program).
METHODS: Three northern Victorian local public health units (Ovens Murray, Goulburn Valley, Loddon Mallee), 8 August - 1 December 2022.
METHODS: People opportunistically recruited at pathology collection centres and by targeted recruitment through community outreach and advertisements. People vaccinated against or who had been diagnosed with Japanese encephalitis were ineligible for participation, as were those born in countries where JEV is endemic.
METHODS: Seroprevalence of JEV IgG antibody, overall and by selected factors of interest (occupations, water body exposure, recreational activities and locations, exposure to animals, protective measures).
RESULTS: 813 participants were recruited (median age, 59 years [interquartile range, 42-69 years]; 496 female [61%]); 27 were JEV IgG-seropositive (3.3%; 95% confidence interval [CI], 2.2-4.8%) (median age, 73 years [interquartile range, 63-78 years]; 13 female [48%]); none were IgM-seropositive. JEV IgG-seropositive participants were identified at all recruitment locations, including those without identified cases of Japanese encephalitis. The only risk factors associated with JEV IgG-seropositivity were age (per year: prevalence odds ratio [POR], 1.07; 95% CI, 1.03-1.10) and exposure to feral pigs (POR, 21; 95% CI, 1.7-190). The seroprevalence of antibody to MVEV was 3.0% (95% CI, 1.9-4.5%; 23 of 760 participants), and of KUNV antibody 3.3% (95% CI, 2.1-4.8%; 25 of 761).
CONCLUSIONS: People living in northern Victoria are vulnerable to future JEV infection, but few risk factors are consistently associated with infection. Additional prevention strategies, including expanding vaccine eligibility, may be required to protect people in this region from Japanese encephalitis.
摘要：
目的：调查2022年日本脑炎爆发后，维多利亚州北部日本脑炎病毒（JEV）抗体的分布和流行情况（作为过去感染的证据），寻求确定具有特殊感染风险的人群；调查两种相关黄病毒抗体的分布和流行情况，墨累河谷脑炎病毒（MVEV）和西尼罗河病毒Kunjin亚型（KUNV）。
方法：横断面血清调查（国家JEV血清监测计划的一部分）。
方法：维多利亚州北部三个地方公共卫生单位（OvensMurray，古尔本山谷,LoddonMallee)，2022年8月8日-12月1日。
方法：人们在病理收集中心机会主义招募，并通过社区外展和广告定向招募。接种日本脑炎疫苗或被诊断患有日本脑炎的人没有资格参加，在JEV流行的国家出生的人也是如此。
方法：JEVIgG抗体的血清阳性率，总体上和选定的兴趣因素(职业，水体暴露,娱乐活动和地点，接触动物，保护措施)。
结果：招募了813名参与者（中位年龄，59年[四分位数范围，42-69岁]；496名女性[61%]）；27名JEVIgG血清阳性（3.3%；95%置信区间[CI]，2.2-4.8%）（中位年龄，73年[四分位数范围，63-78岁]；13名女性[48%]；无IgM血清阳性。在所有招募地点确定了JEVIgG血清阳性参与者，包括那些没有确诊的日本脑炎病例。与JEVIgG血清阳性相关的唯一危险因素是年龄（每年：患病率比值比[POR]，1.07；95%CI，1.03-1.10）和暴露于野猪（POR，21；95%CI，1.7-190）。MVEV抗体的血清阳性率为3.0％（95％CI，1.9-4.5％；760名参与者中有23名），和KUNV抗体3.3%（95%CI，2.1-4.8%；761个中的25个）。
结论：居住在维多利亚州北部的人们很容易受到未来的JEV感染，但很少有危险因素与感染有关。额外的预防战略，包括扩大疫苗资格，可能需要保护该地区的人们免受日本脑炎的侵害。
方法：横断面血清调查（国家JEV血清监测计划的一部分）。
方法：维多利亚州北部三个地方公共卫生单位（OvensMurray，古尔本山谷,LoddonMallee)，2022年8月8日-12月1日。
方法：人们在病理收集中心机会主义招募，并通过社区外展和广告定向招募。接种日本脑炎疫苗或被诊断患有日本脑炎的人没有资格参加，在JEV流行的国家出生的人也是如此。
方法：JEVIgG抗体的血清阳性率，总体上和选定的兴趣因素(职业，水体暴露,娱乐活动和地点，接触动物，保护措施)。
结果：招募了813名参与者（中位年龄，59年[四分位数范围，42-69岁]；496名女性[61%]）；27名JEVIgG血清阳性（3.3%；95%置信区间[CI]，2.2-4.8%）（中位年龄，73年[四分位数范围，63-78岁]；13名女性[48%]；无IgM血清阳性。在所有招募地点确定了JEVIgG血清阳性参与者，包括那些没有确诊的日本脑炎病例。与JEVIgG血清阳性相关的唯一危险因素是年龄（每年：患病率比值比[POR]，1.07；95%CI，1.03-1.10）和暴露于野猪（POR，21；95%CI，1.7-190）。MVEV抗体的血清阳性率为3.0％（95％CI，1.9-4.5％；760名参与者中有23名），和KUNV抗体3.3%（95%CI，2.1-4.8%；761个中的25个）。
结论：居住在维多利亚州北部的人们很容易受到未来的JEV感染，但很少有危险因素与感染有关。额外的预防战略，包括扩大疫苗资格，可能需要保护该地区的人们免受日本脑炎的侵害。
