Raw data underlining study findings.

BackgroundReporting two million human Lassa fever (LF) cases with around 10,000 associated annual mortality, the West African sub-region is endemic for Lassa fever virus (LASV). The true incidence of LF is difficult to determine because most LASV-infected individuals show no differentiating clinical signs and symptoms. We investigated the distribution of cases, post-hospitalization survival patterns, and evaluated factors contributing to infection and clinical course of the disease during an outbreak of LF in Ondo State, Nigeria, from 2017 to 2021.MethodsWe extracted LF data from the Integrated Disease Surveillance and Response weekly report of the Nigerian Centre for Disease Control for 2017–2021. Kaplan-Meier estimate was used to describe the probability of survival among the LF cases. Also, a univariable binary logistic regression was used to explore factors associated with mortality among the study participants. Key informant was interviewed and environmental assessments were also done.ResultsLASV infection was confirmed in 1,115 (24.5%) of 4,551 cases with clinical signs suggestive of LF (age 35.24 ± 20.77) and case fatality rate of 25.5%. Hospitalized patients who did not recover within 17 days had less than 50% chance of survival. Age is a strong predictor of survival; hospitalized patients >40 years were significantly more likely than younger ones to experience mortality (Odds ratio:2.46; 95% CI = 1.67–3.62; p ConclusionCurrent case definition in Ondo State identified close to 25% of laboratory confirmed LASV infection. Human activities during the dry season (October–March) are associated with increased LF cases. We propose a One Health disease surveillance approach that synchronizes farming activities with educational campaigns as a mitigation strategy against LASV infection and mortality in Nigeria.背景：据统计，西非次区域累计报告拉沙热（Lassa fever, LF）病例达200万例，年相关死亡病例约10000例，该区域为拉沙热病毒（Lassa fever virus, LASV）的自然流行区。由于大多数拉沙热病毒感染者无特异性临床体征与症状，拉沙热的实际发病率难以准确估算。本研究针对2017-2021年尼日利亚翁多州拉沙热暴发疫情，调查了病例分布特征、住院后生存模式，并评估了与感染及疾病临床进程相关的影响因素。 方法：本研究从尼日利亚疾病控制中心（Nigerian Centre for Disease Control）2017-2021年的综合疾病监测与响应周报中提取拉沙热相关数据。采用Kaplan-Meier估计法描述拉沙热病例的生存概率；同时采用单变量二元logistic回归分析，探索研究对象中与死亡相关的影响因素。此外还开展了关键知情人访谈与环境评估工作。 结果：在4551例具有拉沙热疑似临床症状的病例中，1115例（24.5%）经实验室确认感染拉沙热病毒，患者平均年龄为35.24±20.77岁，病例病死率为25.5%。住院后17天内未康复的患者，其生存概率不足50%。年龄是生存预后的强预测因子：年龄＞40岁的住院患者发生死亡的风险显著高于年轻患者（优势比（Odds ratio）：2.46；95%置信区间（95% CI）：1.67~3.62；P 结论：翁多州现行的病例定义仅能识别出约25%的实验室确诊拉沙热病毒感染病例。旱季（10月至次年3月）的人类活动与拉沙热病例数增加相关。本研究提出一种同一健康（One Health）疾病监测策略，将农业活动与健康教育宣传相结合，作为尼日利亚防控拉沙热病毒感染及死亡的干预措施。