Lassa fever survivors: long-term health effects and chronic sequelae - a scoping review.

INTRODUCTION

Lassa fever is a viral haemorrhagic disease endemic to West Africa. While most infections are mild, severe cases have high morbidity and mortality, with case fatality rates ranging from 15% in mild cases to 60% in severe cases. Survivors often experience chronic health complications, but these long-term effects remain understudied despite their public health significance.

OBJECTIVES

This scoping review synthesises evidence on the long-term health sequelae of Lassa fever, maps key findings from existing studies, and identifies critical gaps to guide future research and clinical care.

METHODS

A systematic literature search was conducted in PubMed/MEDLINE, Embase, and Google Scholar (up to September 2024) for English-language studies reporting physical, psychological, and functional outcomes ≥ 4 weeks post-recovery. Studies were selected using PCC framework (Population: Lassa survivors; Concept: Long-term sequelae; Context: Endemic regions globally). PRISMA-ScR guidelines were followed.

RESULTS

Nine (9) studies from Nigeria, Sierra Leone and Germany were included, comprising three cross-sectional studies, two case-control studies, two case reports, one retrospective descriptive study and one retrospective cohort study. Hearing loss was the most prevalent sequela (16–35% of survivors), often bilateral and sensorineural with associated balance disorders (55%) and social isolation. Neurological sequelae included delayed-onset paraparesis, seizures (37% in on cohort) and cognitive impairment (8.8%). 42% of survivors in one study had ophthalmic manifestations such as cataract and retinal hemorrhage. Depression and delirium were frequently reported.

CONCLUSION

Lassa fever has significant long-term health consequences requiring multidisciplinary care. More research, particularly longitudinal and interventional studies is needed to improve post-recovery outcomes, survivor rehabilitation, inform evidence-based policies and guide resource allocation in endemic regions.