RESUMO
The antibody titres for Brucella arbotus and Br. melitensis in 364 sera from healthy individuals in Nairobi and Naivasha are presented. A majority (96%) had no detectable agglutinins. Reactivity was markedly higher in the Naivasha serum samples, than in those from Nairobi. In Naivasha, seven per cent showed reactivity, whereas in Nairobi a larger majority (98%), showed no reactivity, with antibody titres ranging from 1:20-1:160. Age and sex were found to have no effect on antibody titre distribution in the two populations. The presence of brucellae antibodies in the healthy population screened (with titres upto 1:80) may be due to exposure to brucellae antigens, rather than denoting brucellosis, this titre could therefore be taken as the baseline in the healthy Kenyan population.