Clinical outcomes of Lassa fever in West Africa: A systematic review and meta-analysis

IntroductionLassa fever is an acute viral haemorrhagic fever that poses a substantial public health security threat in West Africa. Due to its non-specific clinical manifestations and the absence of a reliable point-of-care test, diagnosis could be delayed, leading to severe complications and mortality during epidemics. This systematic review aimed to determine the clinical outcomes of LF in West Africa. MethodsA systematic review and meta-analyses were performed by conducting an extensive online search using PubMed, Web of Science, Scopus, CINAHL, and Google Scholar (PROSPERO protocol CRD42024587426). Only articles written in English were included in publications from 2014 to 2024. The analysis followed PRISMA guidelines. The mortality rate of LF was pooled using a random effects model. ResultsWe included 19 studies that contained data from 4177 patients hospitalized with LF of any age. Most of the studies were of retrospective cohort (16/19; 84.2%) study design and were predominantly conducted in Nigeria (16/19; 84.2%). The mortality rate was highest in a Sierra Leonean study (63.0%), whereas group-based analysis among the Nigerian studies identified Owo as having the highest mortality rate of 13% (95% CI: 06-23; I2 =98%). The pooled LF mortality rate was 19% (95% confidence interval [CI]:10-32). The most common complications of LF are acute kidney injury (AKI) at a pooled proportion of 19% (95% CI; 13-26; I2=89%)), followed by abnormal bleeding at a pooled proportion of 17% (95% CI; 9-30; I2=98%), and CNS manifestations at a pooled proportion of 15% (95% CI; 6-32; I2=98%)). ConclusionWith one out of every five hospitalized Lassa Fever patients likely to die in West Africa, accelerating the development of rapid diagnostic tests, licensed vaccines, and novel therapeutics is crucial. Strengthening community engagement, risk communication, and healthcare worker training will enhance early diagnosis and effective case management thereby reducing mortality and severe complications.