IMMUNITY TO TETANUS IN MALE ADULTS IN DAR ES SALAAM, TANZANIA

Objective: To determine immunity to tetanus in male blood donors with previous diphtheriapertussis-tetanus (DPT)/tetanus toxoid (TT) vaccination.Design: A cross sectional study, conducted in September 1999.Setting: Blood bank, Muhimbili Medical Centre, Dar es Salaam, Tanzania.Methods: Using an antigen competition ELISA technique, serum tetanus anti-toxin levels intwo hundred male blood donors were determined.Results: Vaccination history was absent in 43 (21.5%) blood donors, whereas 60 (30%) and97 (48.5%) reported childhood DPT and TT vaccination, respectively. Tetanus anti-toxinwas undetectable in 47 (23.5%) blood donors and the levels were below that consideredprotective (>0.1 IU/ml) in 25 (12.5%). Among those with undetectable level, 43 (91.5%) hadno vaccination history. Time after last DPT/TT vaccination correlated significantly withtetanus anti-toxin levels (r2=-0.331, p=0.001). In multivariate analysis, TT doses received andtime after last vaccination explained 4.8% and 29.4%, respectively, of the variations intetanus anti-toxin levels.Conclusion: Seventy two (36%) male blood donors were susceptible to tetanus and thesusceptibility was highest from 48 years. A regular TT booster dose at 10 yearly intervals isrecommended to provide adequate and long lasting immunity in male adults. Proper keepingof vaccination records is emphasised