Transfusion Transmissible Infections among Voluntary Blood Donors at the University Teaching Hospital, Lusaka, Zambia

Abstract

Background: HIV1&2, HBsAg, anti-HCV and syphilis antibody are mandatory disease marker tests of Transfusion Transmissible Infections (TTIs) conducted on every donated unit of blood in Zambia. Blood is donated by first time voluntary donors and repeat/regular donors of ages between 16 and 65 years. Both first time and regular blood donors undergo the same screening eligibility criteria in the form of medical questionnaire, history and physical examination prior to blood donation. Units, which test positive for any of the four TTIs, are discarded. The cost of producing one unit of blood in Zambia is about $40US and there is need to keep the discard rate to a minimum. The study aimed at finding out which sub-category of donors was responsible for the discards at the Lusaka Blood Transfusion Centre and conversely which was the safest.

Methodology: A cross-sectional study involvingretrospective review of all blood donors and screening records of voluntary non-remunerated donors at the Lusaka Province/UTH Blood Transfusion Centre covering the period of January to December 2012. For each unit of donated blood, information on donor age, gender, whether first or repeat donor and test result of disease marker of the four TTIs was entered on a spreadsheet and subjected to descriptive and inferential analysis.

Results: Of the 16,027 units donated in 2012, 11,516 (71.9%) were from males, and the majority (77.8%) were aged between 16-24 years. The proportion of first time donors was 60.4%. The overall discard rate due to TTIs was 10.1% (1,622). Most discards were for a single disease marker positivity (1526, 94.1%). Disease marker positivity for HIV, Hepatitis B, Hepatitis C, and Syphilis was: 2.9%, 6.0%, 0.6%, and 1.2% respectively. Using multivariate logistic regression, the safest donors (i.e. with a useable unit, not discarded due to a TTI) were females (OR 1.25, 95% CI 1.11-1.41), repeat donors (OR 1.37, 95% CI 1.23-1.53), and those in the age category 16-24 years (OR 2.35, 95% CI 1.95-2.84).

Conclusions: Repeat/regular, female, young (16-24 years of age), voluntary blood donors were the safest source of tested blood at the UTH/Lusaka Province Blood Transfusion Centre in 2012. Hepatitis B remains the most common TTI as a cause for discard and points to the need for adequate prevention strategies. There is a small but significant discard rate due to hepatitis C. The overall 10.1% discard rate due to TTIs suggests an inevitable need to consider safer donor retention strategies as drivers for the sustainable blood transfusion program in Zambia.

Keywords: Blood donors, Transfusion Transmissible Infections, voluntary donors, Zambia