Lassa fever epidemic outbreak causing maternal mortality on pregnant women : A statistical and systematic review on prevalence and occurrence of maternal mortality in Nigeria

Abstract: Introduction/background: Epidemics of infectious diseases (ID) are re-occurring now more often and spreads faster into many different parts of the world due to globalization. The increasing evidence of climate change and man-made events have shown impacts to increase the emergency and re-emerging of animal- borne IDs. Studies claims that background factors of these IDs are biological, environmental and human-lifestyle related changes. The pathogen Lassa fever virus (LASV) is a zoonotic organismthat circulates in rodent reservoirs, and the animal´s hosts are rodent species (rats) of the genus Mastomys natalensis. Mastomys natalensis is primarily the reservoir species of the animal-borne disease of Lassa fever (LF) which is most prevalent in west Africa, particularly in Nigeria. Lassa fever (LF) has limited information with under-documented cases, its health effect on pregnant women especially in Nigeria is within the rural areas of Edo, Ondo, Delta, Ebony, Bauchi, Taraba and Plateau states where maternal mortalities are higher.  Aim: The overarching aim of this thesis is to analyse and discuss the health effects of Lassa fever occurrence and outcomes on pregnant women in Nigeria, with emphasis on the maternal mortality and fatality during pregnancy. Method: A statistical and systematic review was performed from retrospective studies of case series, case-control, observational and cohort studies of patients in Nigeria (pregnant women with gestation ages of pregnancy from 2 weeks –32 weeks) that tested positive to LASV. Publication status and publication date was applied for the inclusion of respective studies by electronic searches via Web of Science, Google scholar, MEDLINE and PubMed. Preferred Reporting Items for Systematic reviews and Meta-Analysis guidelines (PRISMA) was used to illustrate the flow of relevant articles in my study. R-commander and R-Studio software was used to analyze the data and to find the causal significant relationship between LF and maternal mortality using “Linear regression and linear model plot”. Result: The total number of full-text and Peer-view publications on Lassa fever virus cases was 1 609 articles. 94 articles out of the 1 609 articles were eligible for full text revision. Exclusion criteria finally yielded 6 studies that were relatively relevant to my study. However, 3 out of the 6 articles were statistically reviewed to know the influence of Lassa fever and the risk of maternal mortality during pregnancy.  Conclusion: Lassa fever occurrence have significantly shown potential increase in the severity of maternal mortality, and is predominant among pregnant women from 39 - 45 years old in Nigeria especially within the risk endemic areas of Ondo, Edo, Ebony and Bauchi states showing significant long-term diseases on LF affected pregnant women, such as encephalopathy, acute kidney dysfunction and acute kidney failure that leads to further health problems or complications like coma and sensorineural deafness.