Prevalence and incidence of transfusion-transmissible infections among blood donors in Malawi: A population-level study.

BACKGROUND: Voluntary non-remunerated blood donors (VNRBDs) are essential to sustain national blood supplies. Expanding testing capacity for the major transfusion-transmitted infections (TTI) is crucial to ensure safe blood products. Understanding trends in TTIs can inform prioritisation of resources. METHODS: We conducted a retrospective cohort data analysis of routine blood donation data collected from VNRBDs by the Malawi Blood Transfusion Service from January 2015 to October 2021. Variables included age, occupation; and screening results of TTIs (HIV, Hepatitis B and C, and syphilis). We estimated both prevalence and incidence per person-year for each TTI using longitudinal and spatial logistic regression models. RESULTS: Of the 213 626 donors, 204 920 (95.8%) donors were included in the final analysis. Most donors (77.4%) were males, baseline median age was 19.9 (IQR 18.0, 24.1), 70.9% were students, and over 80.0% were single at first donation. Overall TTI prevalence among donors was 10.7%, with HBV having the highest prevalence (3.4%), followed by syphilis (3.3%), then HIV (2.4%) and HCV (2.4%). Incidence per 1000 person-years for syphilis was 20.1 (19.0, 21.3), HCV was 18.4 (17.3, 19.5), HBV was 13.7 (12.8, 14.7), and HIV was 11.4 (10.6, 12.3). We noted geographical variations with the northern region having lower rates of both prevalence and incidence compared to central and southern regions. CONCLUSION: The individual TTI prevalence and incidence rates from this study are consistent with Southern African regional estimates. By identifying geographical variations of TTI prevalence and incidence, these findings could potentially inform prioritisation of blood collection efforts to optimise blood collection processes.

Seroprevalence and trends in transfusion transmissible infections among voluntary non-remunerated blood donors at the Malawi Blood Transfusion Service-a time trend study.

Introduction: Collecting blood from voluntary non-remunerated blood donors from low risk populations is a key strategy for blood safety. Identifying such populations involves analysis of population and blood donor data to identify risk factors for transfusion transmissible infections (TTIs). There are no recent seroprevalence statistics for blood donors in Malawi. This study fills this gap by describing characteristics of blood donors, trend of annual prevalence of HIV, HBV, HCV and syphilis and factors associated with each TTI. Methods: Retrospective analysis of blood donors' records in the MBTS database from 2011 to 2015 was undertaken. Summary statistics were performed to describe characteristics of the blood donors. Univariable and multivariable logistic regression analyses were performed to determine association between prevalence of infections and socio-demographic factors. Time trend analysis was done to assess changes in prevalence. P-value <0.05 was considered statistically significant. Results: The number of blood donors screened over the 5 year period was 125,893. The mean number of donors donating blood per year was 39, 289; median age was 19 years; 82% were male, 87% single and 72% students and56% were repeat blood donors. Overall prevalence of each TTI decreased. The 2015 prevalence was: 3.6% for HBV; 1.9% for HIV; 2.6% for Syphilis and 1.0% for HCV while the 2011 prevalence was 4.7% for HBV; 3.5% for HIV 3.2% for syphilis and 2.4% for HCV.Repeat blood donors had significantly lower prevalence of TTIs than first time donors. Females were associated with lower risk for HBV, HCV and syphilis. Age ≥25 years and being out of school were associated with HIV. Age ≥25 years was associated with reduced risk for HCV and being self-employed and married were each associated with syphilis. Conclusion: The typical blood donor is a young single male student. Repeat blood donation improves safety of the blood supply.