Incidence and determinants of transfusion-transmissible infections in voluntary blood donors in Malawi, 2005 - 2015

Abstract

Introduction. Blood transfusion has been associated with a high risk of blood transfusion– transmissible infections (TTIs), which include: Human immunodeficiency virus (HIV), Hepatitis C virus (HCV), Hepatitis B virus (HBV), Syphilis, and malaria among others. These infections pose great threats to the global population particularly in sub-Saharan Africa (SSA) where the burden of disease is alarmingly high. This calls for the need to monitor blood supply safety, understand the trend of transmission routes, and develop effective donor behavioural screening. Therefore, the objectives of the study were to describe the baseline characteristics of the study population, determine the incidence of transfusion transmissible HIV, HCV and HBV infections, and to identify factors that are associated with the incidence of infection in blood donors in Malawi through the period of 2005 – 2015. Methods. This was secondary data analysis of a cohort of blood donors from the Malawi Blood Transfusion Service (MBTS). The data were obtained from the MBTS database on blood donors registered from 2005 – 2015. The data was cleaned, and duplicate records checked. Baseline characteristics of donor participants by TTI, HIV, HBV and HCV status were described using frequency distribution tables. Age as a continuous variable was described using median and interquartile range (IQR) and histograms. Categorical variables were summarized using percentages. Kaplan-Meier plots were generated to assess the survival patterns for TTI, HIV, HBV and HCV and log-rank tests for equality of survivor function across strata for all exposure variables were performed. Bivariate and multivariate regression was used to determine risk factors for transfusion transmissible HIV, HCV and HBV infections. The odds ratio with a 99% confidence interval was calculated. A p-value< 0.02 was considered statistically significant. Results. Overall, TTI incidence was 43.4 per 10,000, and this was significantly higher for donors aged 16–19 (IR= 49.81, 95% CI= 44.87–55.29), males (IR= 46.36, 95% CI= 44.76– 48.03), unmarried donors (IR= 43.91, 95% CI= 42.40–45.48), unemployed (IR= 65.23, 95% CI= 51.43–82.74), living in the Southern region (IR= 49.09, 95% CI= 46.97–51.30), unprotected sex with multiple partners (IR= 49.13, 95% CI= 44.50–54.25), and malariapositive donors (IR= 50.42, 95% CI= 47.91–53.05). There were statistically significant differences in survival experience with respect to age category, sex, marital status, unemployment status, region of residence, sex with multiple partners without condom use, and other TTIs. The risk of TTI increased with age and this was similar for HIV and HBV. For HCV, risk of infection decreased with increasing age. Age groups 16–19 (aOR= 1.82, 95% CI= 1.15–2.89), 20–24 (aOR= 2.15, 95% CI= 1.36–3.41), 25–29 (aOR= 2.13, 95% CI= 1.33–3.39), 30–34 (aOR= 2.69, 95% CI= 1.67–4.34), and 35–39 (aOR= 2.00, 95% CI= 1.19–3.35), and married status (aOR= 1.93; 95% CI= 1.38–2.69) was significantly associated with higher odds of TTI in the multivariate logistic model. Infection with syphilis was a common significant risk factor for incident HIV (aOR= 2.62, 95% CI= 1.57–4.38), HCV (aOR= 2.03, 95% CI= 1.04–3.98), and HBV (aOR= 1.71, 95% CI= 1.01–2.89). Conclusion. The overall incidence of TTIs in the Malawian donor population is low, however, the risk of TTI remains a cause for concern. The incidence of HIV, HCV and HBV was highest in males, the unemployed, donors living in the Central Region, engaging in unprotected sex with multiple partners, and co-infection with syphilis. HBV was most common among supposedly healthy donors, followed by HIV and HCV, which revealed a substantial risk of TTI. Age, male sex, married status were significant risk factors associated with TTI in Malawian blood donors. TTI therefore, remains a cause for concern toward availability and safe blood transfusion. An urgent need to continue monitoring the incidence of TTI markers in the donor population through use of more contextualised screening questionnaires and the use of nucleic acid testing (NAT) in addition to serological tests is paramount.