Abstract
BACKGROUND: The peripartum period is both a highly vulnerable stage and a significant indicator of a population's health status. Interest is increasing in human T-cell lymphotropic virus type-1 (HTLV-1) transmission due to its adverse health impacts. However, nationally representative data on HTLV-1 that are important for health planning are unavailable for this subpopulation. PURPOSE: This study aimed to conduct a pooled estimate of HTLV-1 prevalence among pregnant women in Nigeria to quantify its clinical burden and public health implications. METHODS: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 statement. RESULTS: After a systematic review of the Nigerian literature, 12 studies (2,821 pregnant or postnatal women) were included in the final evidence synthesis. The estimated HTLV-1 prevalence in Nigerian peripartum women following a positive screening test by enzyme-linked immunosorbent assay was 5.44% (95% confidence interval [CI], 3.16%-9.20%). A subgroup analysis of the 2 major regions showed a slightly higher prevalence in the Western versus Southern region (5.55% [95% CI, 2.49%-11.87%]; and 4.91% [95% CI, 2.11%-11.02%]; P=0.84). However, a subgroup analysis by geopolitical zone revealed that Southwestern and Northwestern Nigeria had the highest prevalence (9.23% [95% CI, 4.35%-18.55%; I2=93%] and 7.15% [95% CI, 1.54%-27.54%]; I2=92%). Our decade-old subgroup analysis found inconsistencies in the HTLV-1 prevalence. Furthermore, our literature review revealed a prevalence of HTLV infection among patients with various clinical types of lymphomas/leukemias and myelopathy of 2%-22%. CONCLUSION: These findings have important implications in defining the epidemiological patterns of HTLV-1 infection in Nigeria. They also suggest the presence of HTLV-endemic clusters near low-endemic areas, even within the same geopolitical zones.