Impact of Comorbidities on Lassa Fever Outcomes: A 7-Year Retrospective Analysis of Cases Managed at Infection Control and Research Centre FMC Owo
Isaac Ihinmikaye *
Infection Control and Research Centre, FMC Owo, Ondo State, Nigeria.
Olubukola Ayoola Ojo
Department of Internal Medicine, FMC Owo, Ondo State, Nigeria.
Jean Paul Yassa Guilavogui
Department of Public Health, Conakry, Guinea.
Adesola Olawumi Kareem
Department of Community Health, FMC Owo, Ondo State, Nigeria.
Adetunji Adetumi Subulade
Molecular Laboratory, FMC Owo, Ondo State, Nigeria.
Olufunke Bosede Gbenga-Ayeni
Department of Health Information Management, FMC Owo, Ondo State, Nigeria.
Emmanuel Temitope Taiwo
Infection Control and Research Centre, FMC Owo, Ondo State, Nigeria.
Olalekan Ezekiel Ojo
Department of Internal Medicine, FMC Owo, Ondo State, Nigeria.
Esther Jackson Fioboah
Infection Control and Research Centre, FMC Owo, Ondo State, Nigeria.
Michael Babatunde Adeojo
Department of Health Information Management, FMC Owo, Ondo State, Nigeria.
Oluwafemi Oladele Ayodeji
Infection Control and Research Centre, FMC Owo, Ondo State, Nigeria.
*Author to whom correspondence should be addressed.
Abstract
Background: Lassa fever (LF) remains a major public health challenge in West Africa, particularly Nigeria, where recurrent outbreaks contribute substantially to morbidity and mortality. Although most infections are mild or asymptomatic, severe disease may involve multi-organ dysfunction and poor outcomes. The influence of underlying comorbidities on disease severity remains inadequately characterised, despite its relevance to clinical management and risk stratification.
Objective: To determine the prevalence of comorbidities and assess their effect on Lassa fever severity and clinical outcomes among patients managed at a tertiary isolation centre in Nigeria.
Methods: This retrospective analytical study reviewed medical records of confirmed Lassa fever cases managed at the Infection Control and Research Centre, Federal Medical Centre, Owo, from 2018 to 2024. A total of 131 patients with documented comorbidities were included. Socio-demographic characteristics, comorbid conditions, and clinical outcomes were extracted using a structured checklist. Data were analysed using SPSS version 27. Descriptive statistics summarised patient characteristics, while chi-square and likelihood ratio tests assessed associations. Multivariable logistic regression identified independent predictors of disease severity, with statistical significance set at p < 0.05.
Results: Of 1,682 cases reviewed, 131 (7.79%) patients with Lassa fever and comorbidities were included. The mean age was 50.01 ± 15.63 years, and 58.8% were female. Hypertension (48.7%), peptic ulcer disease (24.7%), and diabetes mellitus (20.3%) were the most common comorbidities. Age was significantly associated with hypertension (p < 0.001), diabetes mellitus (p = 0.010), and peptic ulcer disease (p = 0.001), with the highest burden among individuals aged 40–59 years. Only peptic ulcer disease (PUD) was significantly associated with Lassa fever severity (p = 0.008). Multivariable analysis identified PUD as an independent predictor of severe disease (adjusted odds ratio [AOR] = 2.901; 95% CI: 1.292–6.513; p = 0.010), indicating an almost threefold increase in complication risk.
Conclusion: Comorbidities were common among patients with Lassa fever. Hypertension, PUD, and diabetes mellitus were most frequently documented. PUD independently predicted severe disease, supporting targeted monitoring, early intervention, and routine comorbidity screening to strengthen risk-based clinical management.
Keywords: Lassa fever, comorbidities, hypertension, diabetes mellitus, peptic ulcer disease, disease severity, clinical outcomes, retrospective analysis, risk stratification