[Differences in rubella immunity in Mali and Hamburg and their consequences]

The rare occurrence of rubella embryopathy in Mali stimulated us to investigate the rubella immunity of the population. Sera from females from Hamburg (n = 97) between 16 and 42 years old were in 84,5% seropositive (hemolysin-in-gel test) whilst a sample of Malien females (n = 99) were positive in 92,9%. Our investigations showed that the Malien children were significantly (p = less than 0.001) earlier infected by rubella than in Hamburg (Mali: children under 8 years [n = 196] in 46.9%; Hamburg [n = 151] in 20.5%). In Mali 7-8 years old children were already in 87.5% seropositive (Hamburg: only in 46.7%). The early immunity in childhood is due to the bigger African family in comparison with the smaller European family. The height of rubella serum titers was in grown-ups identical, but the relationship was vice versa in both studied newborn populations. Newborns from Mali showed lower rubella antibody titers than their mothers (newborns from Hamburg had a tendency to higher titers). Similar relationships were found already in the amount of neutralizing polioantibodies in newborns from both countries. A rubella immunisation in Mali seems not to be indicated.