Blood Safety: On-Site Verification Of The Screening Of HIV, HBV And HCV By Enzyme Linked Immuno-Sorbent Assay (ELISA) Kits From Bio-Rad Laboratories At The “Centre National De Transfusion Sanguine” (CNTS) Of Lomé In Togo

Background: Blood transfusion improves health and saves lives. Safe blood must be ensured for our populations. Quality assurance is a process that includes a set of coordinated activities in order to achieve the quality objective. Compliance with the quality management rules of medical biology laboratories requires verification of methods prior to their use. This study aimed to verify the on-site verification of the performance of the Enzyme Linked Immuno-Sorbent Assay (ELISA) method performed at the serology laboratory of the CNTS of Lomé. Methods: The performance of ELISA method performed at the serology laboratory of CNTS for the diagnosis of HIV, Hepatitis B and C with Bio-Rad Genscreen ULTRA-HIV Ag-Ac, Bio-Rad Monolisa-HBs Ag ULTRA and Bio-Rad Monolisa HCV Ag-Ac ULTRA V2 kits respectively was evaluated on repeatability, reproducibility, sensitivity and specificity according to COFRAC's SH GTA 04 reference. Results: The evaluation of the repeatability and reproducibility of each kit used in the laboratory resulted in compliant Coefficients of Variation (CV) with manufacturers’ ones. Sensitivities obtained with Bio-Rad Monolisa HCV Ag-Ac ULTRA V2, Bio-Rad Monolisa HBs Ag ULTRA and Bio-Rad Genscreen ULTRA HIV Ag-Ac kits were 94.59%, 98.08% and 100% respectively. For specificity tests, we found 86.49% with BIO-Rad Genscreen ULTRA-HIV Ag-Ac kit, 94.34% with Bio-Rad Monolisa HCV Ag-Ac ULTRA V2 kit and 97.37% with Bio-Rad Monolisa-HBs Ag ULTRA. Conclusion: In general, results were compliant except HIV diagnosis specificity. This study appears as a contribution to the establishment of a verification file for ELISA method used at the serology laboratory of CNTS of Lomé.

Syphilis Seroprevalence among Blood Donors at the Chad National Blood Transfusion Center in N’Djamena

This involves evaluating the risk of syphilis transfusion in blood donors having a reaction to the group antigen and confirming positive or negative by the treponemal test. From August 2019 to August 2020, an observational study of syphilitic markers was conducted with blood donors (replacement families and volunteers non-remunerated) at the Center National de Transfusion Sanguine de N’Djamena. The donors included were also tested negative for the markers (HBsAg, Ab anti HCV, Ag /Ab HIV) according to standard methods of clinical microbiology. During one year, 24587 donors were identified of which 654 (2.65%) were confirmed positive by the treponemal test. Different positive rates of syphilis were determined in family replacement donors (94%), voluntary non-remunerated donors (6.12%), male (86%) and female (13%) respectively. This study determined a level of specific antigen for syphilis in a study population that reacted positively to the non-treponemal test. In view of this result, we recommend screening with the treponemal test in any blood donor having a reaction with a non-treponemal test in order to minimize the residual risk of transmission of syphilis among blood donors in Chad.