INTRODUCTION:
Communicable diseases account for 28% of all deaths in Africa1. They contribute to 704 million DALYs2, with four key diseases—HIV, HBV, HCV, and syphilis—transmissible through transfusions of contaminated blood, known as Transfusion-Transmissible Infections (TTIs). The WHO recommends mandatory testing of all donated blood for TTIs3. TTIs present asymptomatically in most donors, risking chronic liver disease and immune suppression4,5. Ensuring a safe and sustainable blood supply is a public health priority. Sub-Saharan Africa faces a shortage of safe blood6, a high pooled TTI prevalence of 10.1%7, and an even higher prevalence of 2.0% in the SADC8. The study aimed to determine the prevalence, predictors and distribution of TTIs in Lesotho from 2013 to 2023.

METHODS:
A retrospective cross-sectional study was used to analyse data from the Blood Safety Information. Systematic random sampling was applied to select 385 donors annually over 11 years, yielding a total of 4227 donors. Data was processed using Python and Microsoft Excel and analysed in SPSS using descriptive statistics and Chi-square tests to calculate prevalence, assess the association between donor characteristics (age group, gender, residence district, donor status, and donor type) and TTI positivity, a trend and spatial distribution. The significance level was p < 0.05.

RESULTS:
The TTI prevalence in Lesotho was 6.7%, and HIV (2.96%), syphilis (3.10%), HBV (0.85%), and HCV (0.40%). Gender and age were significantly associated with TTI positivity (p = 0.009 and p < 0.001, respectively), with higher prevalence among females and donors aged 20–39 years. First-time donors had higher TTI (69.6%) and HIV (72.0%) cases (p < 0.001). TTI prevalence showed an overall increasing trend, alongside a shift from voluntary to family-replacement donors. All Lesotho districts recorded TTIs.

CONCLUSIONS:
There is a growing burden of TTs in Lesotho, driven largely by high HIV and syphilis.