[Absence of the antigen H:z66 in 2355 strains of Salmonella typhi from Madagascar and several countries of tropical Africa].

The presence of the new flagellar antigen H:z66 (Guinée, 1981) was investigated among 2,355 strains of S. typhi isolated from 1981 to 1985 in Madagascar and some countries of tropical Africa: Burundi, Ivory Coast, Gabon, Mauritania, Central African Republic, Rwanda, Senegal, Zaïre. A method based on the immobilization of motile strains in soft agar with immunserum anti-H:d, was used to detect strains carrying antigen H:z66. No African and malagazy strains had antigen H:z66, irrespective to their biovar, phage-type, drug susceptibility and geographical origin. These results were compared with a study of 2,121 indigenous or imported strains of S. typhi isolated in France during the same period. Except 4 strains from patients contaminated in Indonesia, all of them were also devoid of antigen H:z66. Future research is needed for a complete assessment of the geographical distribution of S. typhi antigen H:z66.