Seroprevalence of Maternal Peripartum HTLV-1 Infection: A Systematic Review and Meta-Analysis of the Nigerian Literature

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 leukemia 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. 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. This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 statement. After a systematic review of the Nigerian literature, 12 studies (2821 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 two 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; I 2 , 93%] and 7.15% [95% CI, 1.54–27.54]; I 2 , 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%. 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.