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.