[Salmonellosis in Dakar: bacteriological, clinical, epidemiological and therapeutic aspects. Ten years records...

A study on salmonellosis in Senegal has been carried out in Dakar at the University Hospital of Fann from 1966 to 1976. The authors describe the various methods of isolating the germs (mainly hemoculture and coproculture) and the techniques used for bacteriological research (antibiograms, tests on plasmidic resistance). The results of these investigations, which took the whole of 10 years, are presented below, in accordance with their different aspects: - bacteriological: 1 335 strains of Salmonella have been isolated. Significantly, S. typhi is predominant (56,6 p. 100). But 7 serotypes represent 90 p. 100 of the total strains which are now in existence in Dakar; - clinical: the aspects of these diseases vary: typhoïd fever, encephalitis, diarrheic syndrome, especially among infants, and purulent meningitis, which is generally severe; - therapeutic: 880 strains have been tested with 10 antibiotics. Two groups of Salmonella serotypes are opposed: those which are sensitive (S. typhi, S. typhi murium, S. enteritidis, S. paratyphi C), those which have become resistant (S. stanleyville, S. havana, S. ordonez). The most frequent antibiotype of this kind is ASKCTSu. This is a phenomenon of plasmidic resistance, demonstrated by in vitro experiments; - epidemiological: the lysotypes of 86 strains have been determined. Two epidemiological features must be described: either a stable endemic situation with sensitive strains - or epidemics, lasting several years, with resistant serotypes. Different therapeutic schemes can be used: chloramphenicol for typhoid fever, or sometimes cotrimoxazole, or ampicillin for meningitis. In diarrheic syndrome, symptomatic treatment is enough. Then, the authors give their comments on the special characteristics of salmonellosis in Dakar: - the influence of environment on the various clinical aspects of these diseases: very serious cases of meningitis, typhoid fever, which is more severe than in France, and complications when treatment has gone wrong at the beginning; - antibiograms, which are essential, in order to choose the adequate therapeutics; - and the different aspects of epidemillogy, which are linked to the sensitivity of the serotypes to the most active antibiotics. The existence of several resistant serotypes in Senegal is a real danger: plasmidic resistance could be transferred to S. typhi. In such a situation, epidemiological surveillance of salmonellosis is absolutely necessary, and control of enteric diseases, characterized by foecal transmission, must be carried out, with the techniques available in the country.