Diphtheria immunity in Mali (mothers and their neonates and children under two years of age.

An analysis of diphtheria antibodies (indirect haemagglutination technique) in 85 paired sera of Malian mothers and their newborns (cord blood) showed that all mothers had protective antibody levels (greater than 0.1 I.U./ml). 81 per cent of the neonates demonstrated protective immunity towards diphtheria. Since in Mali respiratory diphtheria is rare, is may be assumed that a silent immunization by skin sores, contaminated with diphtheria germs takes place. This assumption is supported by an analysis of 30 unimmunized 6 to 24 months old babies from whom 10 had protective and 16 low levels of diphtheria antibodies in their sera. By inclusion of 13 further children of the same age group (possibly previously immunized, since they had demonstrable antibodies against tetanus) we found a geometric mean diphtheria antibody titer for all 43 children of 0,08 I.U./ml.