Transfusion safety in francophone African countries: an analysis of strategies for the medical selection of blood donors.

BACKGROUND: The goal of selecting a healthy blood donor is to safeguard donors and reduce the risks of infections and immunologic complications for recipients. STUDY DESIGN AND METHODS: To evaluate the blood donor selection process, a survey was conducted in 28 blood transfusion centers located in 15 francophone African countries. Data collected included availability of blood products, risk factors for infection identified among blood donor candidates, the processing of the information collected before blood collection, the review process for the medical history of blood donor candidates, and deferral criteria for donor candidates. RESULTS: During the year 2009, participating transfusion centers identified 366,924 blood donor candidates. A mean of 13% (range, 0%-36%) of the donor candidates were excluded based solely on their medical status. The main risk factors for blood-borne infections were having multiple sex partners, sexual intercourse with occasional partners, and religious scarification. Most transfusion centers collected this information verbally instead of having a written questionnaire. The topics least addressed were the possible complications relating to the donation, religious scarifications, and history of sickle cell anemia and hemorrhage. Only three centers recorded the temperature of the blood donors. The deferral criteria least reported were sickle cell anemia, piercing, scarification, and tattoo. CONCLUSIONS: The medical selection process was not performed systemically and thoroughly enough, given the regional epidemiologic risks. It is essential to identify the risk factors specific to francophone African countries and modify the current medical history questionnaires to develop a more effective and relevant selection process.

Analysis of hepatitis C virus strains circulating in Republic of the Congo.

The aim of this study was to assess the seroprevalence, viremia, genotype distribution, and demographic history of hepatitis C virus (HCV) in the Republic of the Congo. Testing was carried out on sera samples collected in 2005 from 807 Bantus belonging to the Kongo, Teke, and Ngala subgroups and 80 Pygmies. Positive HCV serology was found in 50 (5.6%) individuals including 31 (60%) who were viremic. Seroprevalence increased with age with a cutoff at 50 years: 2.8% <50 versus 12% >50. Twenty-one strains belonged to four described subtypes, that is, 4c in eight cases, 4h in two, 4k in three, and 4r in eight. Ten strains could not be assigned to any known subtype and may represent six new variants, that is, subtype 4 in five cases and subtype 2 in one. Evolutionary analysis of subtype 4c and 4r sequences indicated a period of enhanced transmission in the mid-twentieth century probably due to iatrogenic causes. This study underlines the high genetic diversity of strains in the Republic of the Congo with nine subtypes 4 and one subtype 2.

Molecular analysis of inactive and active RHD alleles in native Congolese cohorts.

BACKGROUND: In Africa, RHD alleles have not been fully characterized. The purpose of this study was to identify inactive and active RHD alleles at the molecular level in Congolese cohorts. STUDY DESIGN AND METHODS: Blood samples were collected from people living in central Congo populated by Teke ethnic group. A total of 110 D- and 40 D+ samples from Congo-Brazzaville and Teke groups, respectively, were selected for RHD genotyping using allele-specific primer polymerase chain reaction and sequencing. RESULTS: In the 110 D- samples, RHD exon amplifications were observed in 7 samples that were subsequently identified by sequencing as weak D type 4 variants. In the remaining 103 D- samples, the frequencies of RHD gene deletion, RHDpsi pseudogene, and RHD-CE-D(s) hybrid gene were 0.75685, 0.20560, and 0.04468, respectively. In the D+ samples, 26 individuals carried at least a regular RHD gene; 9 carried aberrant RHD alleles belonging to the African D clusters, that is, DAU, DIVa, and weak D type 4; 3 carried RHDpsi in trans with a DAU allele including one novel RHD allele (V279M, S333N, T379M) named DAU-7; and 2 others were partially determined. CONCLUSION: This study revealed a high frequency of weak D type 4 alleles that confirmed the need to use indirect antiglobulin test to improve transfusion safety in the Congo and in countries hosting Congolese people. Findings also indicated that there is a geographic variation in RHD allele distribution and showed that RHD gene deletion is the most prevalent cause of the D- phenotype in the Congolese population.