Case Series of Recrudescence in Lassa fever - The Alex Ekwueme Federal University Teaching Hospital, Abakaliki (AEFUTHA) Experience.

• ¹, Department of Medicine, Alex Ekwueme Federal University Teaching Hospital Abakaliki, Ebonyi State, Nigeria, NG

Background: In resource limited settings with constraints in both technical capacity and equipment, persistent high-grade fever > 38 C unresponsive to anti-malarial or antibiotics  remains a key feature in defining a suspect Lassa fever (LF) case especially against the background of an  on-going epidemic. We describe case series of Lassa fever recrudescence based on experiences at AEFUTHA from 2017, 2018 and 2022 epidemics. We further explore the role of salvage therapy, highlight neurological manifestations of LF with a negative PCR and the possible benefits of such therapy in immune mediated complications of LF.
Case Presentation: Six RT-PCR confirmed LF cases were commenced on ribavirin using the McCormick regimen. Fifty percent of them became afebrile by day 5 of ribavirin therapy and remained so for a variable period of 4 -7 days (average 5 days) before resurgence of fever. The remaining 50% became afebrile between days 11 - 16 of ribavirin administration and remained so for similar variable period before resurgence of fever. They all needed additional course(s) of ribavirin (prolonged and modified ribavirin regimen) to become and remain afebrile. The additional courses of ribavirin varied from 23g – 97g (mean 50 ± 10g) to achieve afebrile and asymptomatic states. Blood cultures and malaria parasite tests performed during relapse of fever were unremarkable. On attaining afebrile states, repeat RT-PCR were negative for all the patients. It took between 5 -35 days (mean ± SD, 15 ± 4 days) to achieve this, and no gender difference was observed. The initial early resolution of fever prior to resurgence had no relationship to the duration or total dose of ribavirin needed to achieve an afebrile state.
Conclusions: Our clinical experience in the management of these cases suggests a potential challenge of LF recrudescence. This possibly argues for a re-evaluation of the traditional ribavirin regimen for the management of LF.