[Typhoid fever in Vietnam. I. Bacteriological study (607 Salmonella strains isolated from 1961 to 1975 at the Grall Hospital of Saigon)].

From 1961 to 1975, researches on salmonellosis have been carried out in Hospital Grall, in Saigon, mainly during two periods (1961-1964, then 1971-1975). 607 strains of Salmonella have been isolated for these 15 years (558 S. typhi and 49 Salmonella, among several other serotypes). As typhoid fever is most important, the authors have studied this disease very carefully. The most efficacious technique of isolating is hemoculture. With coproculture, the results are disappointing. Scarcely, some strains have been found in samples of various origins. Indirect diagnosis methods are less interesting. They may induce only a presumptive diagnosis. S. typhi is always predominant : 86,5 p. 100 from 1961 to 1964 and 96,1 p. 100 from 1972 to 1975. Diffusion of this germ during the second period is linked to the occurring of resistance to chloramphenicol. Some other serotypes are observed scarcely. The lysotypes have been determined for almost all the strains (202, then 323, during the two phases of this study). From 172 to 1975, 24 different lysotypes have been found. Lysotype I + IV is predominant (59 p. 100), but the incidence of D 6 and of 46 (6,8 p. 100) is somewhat high, if it is compared to the others. Lysotype 46 has been observed only since 1971. It has been spreading up to now in South East Asia. Stretching of this lysotype, out of its original focus, is an important epidemiological character. In 1972, resistance of S. typhi to chloramphenicol appeared and it has been increasing mostly during the following years. From 1972 to 1975, 211 strains on 288 were found resistant (highest point in 1975 : 85,4 p. 100). It was a multiresistance to 4 antibiotics (antibiotype : CTSSu). This pehnomenon of plasmidic resistance was investigated in Institut Pasteur (Paris). Many lysotypes have been involved in resistance (14 among 24). Clinical study has been realized for 189 patients. During the typical period of the disease, fever is the major symptom. More scarcely, other clinical features are observed. Various complications have been related. The evolution of the disease has been generally satisfactory, as far as mortality (less than 2 p. 100), sequelae (1 p. 100) and relapses (2 p. 100) are concerned. Clinical course has not been modified by resistance of the germs.