PDF(Pubmed)
Abstract：
There is limited epidemiological evidence on Lassa fever in pregnant women with acute gaps on prevalence, infection incidence, and risk factors. Such evidence would facilitate the design of therapeutic and vaccine trials and the design of control programs. Our study sought to address some of these gaps by estimating the seroprevalence and seroconversion risk of Lassa fever in pregnant women.
We conducted a prospective hospital-based cohort between February and December 2019 in Edo State, Southern Nigeria, enrolling pregnant women at antenatal clinic and following them up at delivery. Samples were evaluated for IgG antibodies against Lassa virus. The study demonstrates a seroprevalence of Lassa IgG antibodies of 49.6% and a seroconversion risk of 20.8%. Seropositivity was strongly correlated with rodent exposure around homes with an attributable risk proportion of 35%. Seroreversion was also seen with a seroreversion risk of 13.4%.
Our study suggests that 50% of pregnant women were at risk of Lassa infection and that 35.0% of infections might be preventable by avoiding rodent exposure and conditions which facilitate infestation and the risk of human-rodent contact. While the evidence on rodent exposure is subjective and further studies are needed to provide a better understanding of the avenues of human-rodent interaction; public health measures to decrease the risk of rodent infestation and the risk of spill over events may be beneficial. With an estimated seroconversion risk of 20.8%, our study suggests an appreciable risk of contracting Lassa fever during pregnancy and while most of these seroconversions may not be new infections, given the high risk of adverse outcomes in pregnancy, it supports the need for preventative and therapeutic options against Lassa fever in pregnancy. The occurrence of seroreversion in our study suggests that the prevalence obtained in this, and other cohorts may be an underestimate of the actual proportion of women of childbearing age who present at pregnancy with prior LASV exposure. Additionally, the occurrence of both seroconversion and seroreversion in this cohort suggests that these parameters would need to be considered for the development of Lassa vaccine efficacy, effectiveness, and utility models.
We conducted a prospective hospital-based cohort between February and December 2019 in Edo State, Southern Nigeria, enrolling pregnant women at antenatal clinic and following them up at delivery. Samples were evaluated for IgG antibodies against Lassa virus. The study demonstrates a seroprevalence of Lassa IgG antibodies of 49.6% and a seroconversion risk of 20.8%. Seropositivity was strongly correlated with rodent exposure around homes with an attributable risk proportion of 35%. Seroreversion was also seen with a seroreversion risk of 13.4%.
Our study suggests that 50% of pregnant women were at risk of Lassa infection and that 35.0% of infections might be preventable by avoiding rodent exposure and conditions which facilitate infestation and the risk of human-rodent contact. While the evidence on rodent exposure is subjective and further studies are needed to provide a better understanding of the avenues of human-rodent interaction; public health measures to decrease the risk of rodent infestation and the risk of spill over events may be beneficial. With an estimated seroconversion risk of 20.8%, our study suggests an appreciable risk of contracting Lassa fever during pregnancy and while most of these seroconversions may not be new infections, given the high risk of adverse outcomes in pregnancy, it supports the need for preventative and therapeutic options against Lassa fever in pregnancy. The occurrence of seroreversion in our study suggests that the prevalence obtained in this, and other cohorts may be an underestimate of the actual proportion of women of childbearing age who present at pregnancy with prior LASV exposure. Additionally, the occurrence of both seroconversion and seroreversion in this cohort suggests that these parameters would need to be considered for the development of Lassa vaccine efficacy, effectiveness, and utility models.
摘要：
背景：关于拉沙热在孕妇中的流行病学证据有限，感染发生率，和风险因素。这些证据将促进治疗和疫苗试验的设计以及控制计划的设计。我们的研究试图通过估计孕妇拉沙热的血清阳性率和血清转换风险来解决其中的一些差距。
结果：我们于2019年2月至12月在江户州进行了一项基于医院的前瞻性队列研究，尼日利亚南部,在产前诊所登记孕妇，并在分娩时跟进她们。评估样品的针对拉沙病毒的IgG抗体。该研究表明，拉萨IgG抗体的血清阳性率为49.6％，血清转换风险为20.8％。血清阳性与房屋周围的啮齿动物暴露密切相关，归因风险比例为35％。血清水平也有13.4%的血清水平。
结论：我们的研究表明，50%的孕妇有感染拉沙的风险，35.0%的感染可以通过避免啮齿动物的暴露和促进侵染的条件以及人类与啮齿动物接触的风险来预防。虽然关于啮齿动物暴露的证据是主观的，需要进一步的研究来更好地了解人类与啮齿动物相互作用的途径；降低啮齿动物侵染风险和溢出事件风险的公共卫生措施可能是有益的。估计血清转换风险为20.8%，我们的研究表明，怀孕期间感染拉沙热的风险很大，虽然大多数这些血清转化可能不是新的感染，鉴于妊娠不良结局的高风险，它支持在怀孕期间预防和治疗拉沙热的需要。在我们的研究中，血清学转化的发生表明，在这一研究中获得的患病率，和其他队列可能低估了在怀孕时出现LASV暴露的育龄妇女的实际比例。此外,该队列中血清转化和血清转化的发生表明，这些参数需要考虑拉沙疫苗效力的发展，有效性,和实用新型。
结果：我们于2019年2月至12月在江户州进行了一项基于医院的前瞻性队列研究，尼日利亚南部,在产前诊所登记孕妇，并在分娩时跟进她们。评估样品的针对拉沙病毒的IgG抗体。该研究表明，拉萨IgG抗体的血清阳性率为49.6％，血清转换风险为20.8％。血清阳性与房屋周围的啮齿动物暴露密切相关，归因风险比例为35％。血清水平也有13.4%的血清水平。
结论：我们的研究表明，50%的孕妇有感染拉沙的风险，35.0%的感染可以通过避免啮齿动物的暴露和促进侵染的条件以及人类与啮齿动物接触的风险来预防。虽然关于啮齿动物暴露的证据是主观的，需要进一步的研究来更好地了解人类与啮齿动物相互作用的途径；降低啮齿动物侵染风险和溢出事件风险的公共卫生措施可能是有益的。估计血清转换风险为20.8%，我们的研究表明，怀孕期间感染拉沙热的风险很大，虽然大多数这些血清转化可能不是新的感染，鉴于妊娠不良结局的高风险，它支持在怀孕期间预防和治疗拉沙热的需要。在我们的研究中，血清学转化的发生表明，在这一研究中获得的患病率，和其他队列可能低估了在怀孕时出现LASV暴露的育龄妇女的实际比例。此外,该队列中血清转化和血清转化的发生表明，这些参数需要考虑拉沙疫苗效力的发展，有效性,和实用新型。
