Background and Aim: Several symptomatic cases of hepatitis E virus (HEV) infections were reported to the New Caledonia Island Public Health Service between August and December 2023. This prompted epidemiological and virological investigations to identify the source of infection. Approach and Results: HEV RNA was assessed in symptomatic patients, various food items and pig farms on the island. HEV strains were characterised by sequencing. A seroprevalence study was also conducted on asymptomatic blood donors before and after the outbreak. 127 symptomatic cases were reported. Hospitalisation was required for 29/127 patients (22.8%). Hospitalised patients presented more frequently with comorbidities including liver and cardiovascular diseases, (80.7% vs. 27%, p<0.01) and 3 persons died (2.3%). Among the 100 HEV RNA-positive samples received at the French National Refence Centre for HEV, viral sequencing was possible for 76 samples. All strains were identified as HEV genotype 3 and 74/76 strains were grouped together (nucleotide identity: 98-100%). Full-length sequencing indicated a new HEV-3 subtype within HEV-3 subclade abk. Only genotype 3f strains were detected on the island’s pig farms. No food items tested positive for HEV RNA. The seroprevalence of HEV IgG and IgM in blood donors was 9.2% (9/98) and 0%, respectively, in 2020, rising to 17.3% (17/98) and 2% (2/98) in 2024. Conclusions: Although all previous large-scale epidemics in Asia and Africa were associated with HEV-1 or 2, the New Caledonia outbreak was linked to HEV-3. A high number of symptomatic cases were admitted to hospital with a case fatality rate of 2.3%.

中文翻译：

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新喀里多尼亚岛大规模戊型肝炎病毒基因型 3 疫情


背景和目的： 2023 年 8 月至 12 月期间，新喀里多尼亚岛公共卫生服务部门报告了几例有症状的戊型肝炎病毒 （HEV） 感染病例。这促使流行病学和病毒学调查以确定感染源。方法和结果： 在岛上有症状的患者、各种食品和养猪场中评估 HEV RNA。通过测序对 HEV 菌株进行表征。还对疫情爆发前后的无症状献血者进行了血清阳性率研究。报告了 127 例有症状病例。29/127 名患者 （22.8%） 需要住院治疗。住院患者更频繁地出现包括肝脏和心血管疾病在内的合并症 （80.7% vs. 27%，p<0.01），3 人死亡 （2.3%）。在法国国家 HEV 参考中心收到的 100 个 HEV RNA 阳性样本中，有 76 个样本可以进行病毒测序。所有菌株均被鉴定为 HEV 基因型 3,74/76 菌株被归为一组 （核苷酸同一性：98-100%）。全长测序表明 HEV-3 亚分支 abk 中存在一个新的 HEV-3 亚型。在该岛的养猪场仅检测到基因型 3f 菌株。没有食品的 HEV RNA 检测呈阳性。2020 年献血者 HEV IgG 和 IgM 的血清阳性率分别为 9.2% （9/98） 和 0%，到 2024 年上升到 17.3% （17/98） 和 2% （2/98）。结论： 尽管亚洲和非洲以往所有大规模流行都与 HEV-1 或 2 有关，但新喀里多尼亚疫情与 HEV-3 有关。大量有症状病例入院，病死率为 2.3%。