Conference Abstract | Volume 8, Abstract ELIC2025242 (Poster 051) | Published: 31 Jul 2025
Matthew Temitope Oluwole1,2,&, Stephen Oyegoke Fagbemi1,&, Ayokunle Orimolade1, Gboyega Adekunle Famokun1,2, Aderonke Tolulope Fagbemi3, Olawumi Johnson1, Njideka Esther Kanu4, Funmilola Olanike Adeolu1, Ibraheem Adebayo5, Adebayo Matthew Bakare6, Igbodo Gordon2,7, Adewale Adejugbagbe5, Ohuneni Stephen2,7
1State Ministry of Health (SMOH), Ondo, Nigeria, 2Nigeria Field Epidemiology and Laboratory Training Programme (NFELTP), Abuja, Nigeria, 3Department of Community Health, University of Medical Sciences, Ondo, Nigeria, 4National Primary Health Care Development Agency (NPHCDA), Abuja, Nigeria, 5World Health Organization, Ondo State Field Presence Nigeria, 6State Primary Healthcare Development Agency (SPHCDA), Ondo, Nigeria, 7Nigeria Centre for Disease Control and Prevention (NCDC), Abuja, Nigeria
&Corresponding authors: Matthew Temitope Oluwole, State Ministry of Health (SMOH), Ondo, Nigeria, Email: wole4christ@gmail.com & Fagbemi Stephen, State Ministry of Health (SMOH), Ondo, Nigeria, Email: stephenfagbemi@gmail.com
Received: 11 May 2025, Accepted: 09 Jul 2025, Published: 31 Jul 2025
Domain: Infectious Disease Epidemiology, Disease Surveillance
Keywords: Lassa fever, Mortality, Rate, Age group, Standardization
©Matthew Temitope Oluwole et al. Journal of Interventional Epidemiology and Public Health (ISSN: 2664-2824). This is an Open Access article distributed under the terms of the Creative Commons Attribution International 4.0 License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Cite this article: Matthew Temitope Oluwole et al., Standardization of death rate: Implications for variability in mortality and age-distribution of Lassa fever in Ondo State, Nigeria. Journal of Interventional Epidemiology and Public Health. 2025;8(Conf Proc 5):00195. https://doi.org/10.37432/JIEPH-CONFPRO5-00195
Lassa fever (LF) remains a significant public health challenge in endemic areas in West Africa, including Nigeria due to its high fatalities and outbreak overwhelming the health system. Annual outbreak of LF has been reported in Ondo State. We applied direct standardization and mortality table to gain insights into Lassa fever severity in Ondo State.
We conducted a retrospective review of disease surveillance data and mortality registers from 2019 – 2024. The age, outcome and other variables were extracted and WHO World Standard Population (2000-2025) were adopted. We employed Poisson distribution parameter (x2/v) to generate conservative estimates of variance of the death rate and mortality table to determine life expectancy.
During the six-year review period, there were 2,122 LF laboratory confirmed cases and 339 deaths (CFR: 15.9%), 41 cases among health care workers with 9 deaths. The Local Government Areas with the highest age-standardized incidence, mortality and CFR were Owo (343.8 cases/100,000); (61.5 deaths/100,000) and Akoko South West (36.0%) respectively. The level of uncertainty range around the parameter (x2/v) was computed as (4.98 – 12.64) with mortality estimates of 8.80.
The mortality rate of Lassa fever is growing exponentially at the rate of -1.98% across all ages. The adult mortality age-specific growth rate peaked at 25 – 29 and 60 – 64 years and is expected to double in the year 2030 if the current growth rate persists. The life expectancy at birth, 45.9years (x= 9.19), and a person aged 15 years has 61.5% chances of dying of LF before his 60th birthday.
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