Les infections à Salmonella dublin : résultats préliminaires d'une enquête nationale

Abstract

Une enquête nationale a permis de recenser 155 observations d'infections à Salmonella dublin en France sur une période de 3 ans (1988–1991). Le sexe ratio homme/femme était de 1,9, la répartition par tranche d'âge montrant la prédominance de 3 groupes (enfant < 5 ans, adulte : 26–40 ans, et sujet agé 65–85 ans). S. dublin a été isolé d'hémoculture dans 56,5 % des cas, de coproculture dans 29,5 % des cas, de plusieurs sites différents dans 11 % des cas. La sensibilité aux antibiotiques était la règle (résistance à l'ampicilline 2 %, au chloramphénicol 14 %). Une pathologie sous-jacente considérée comme favorisant la salmonellose était présente dans 57 % des cas : infection à HIV ou SIDA (34 %), leucémie ou autre néoplasie (31 %), corticothérapie (10 %), greffe d'organe (6 %). Sur le plan clinique, les principaux signes observés étaient : fièvre (77 %), gastro-entérite (38,1 %), septicémie (33,5 %), infection urinaire (9 %), pneumopathie (4 %), arthrite septique (4 %). L'antibiothérapie, prescrite dans 75 % des cas, comportait le plus souvent une association. Un échec a été observé dans 15,5 % des cas, avec décés dans 12,2 % des cas. La positivité des hémocultures, un tableau clinique sévère (septicémie), une évolution défavorable étaient plus fréquents chez les patients présentant un terrain pathologique sous-jacent. We conducted a retrospective national survey of Salmonella dublin infections which occurred in France during the period 07/1988 to 06/1991. For all cases whose identification was confirmed by the National Reference Laboratory on Salmonella, a questionnaire was sent to clinicians in order to collect epidemiological, clinical, bacteriological and therapeutic aspects. Complete information was obtained for 155 cases (male: 66%, female: 34%). Blood was the most frequent site of S. dublin isolation (56.5%), followed by stools (29.5%). In 11% of cases, S. dublin was isolated from ≥ 2 different sites. Antibiotic susceptibility of isolates was the rule, although 2% of strains were ampicillin-resistant and 14% chloramphenicol-resistant. S. dublin was more prominent in patients of three groups of age (infants aged 0 to 5, young adults [25–40 years-old], elderly [65–85 years-old]). An underlying disease was present in 57% patients : HIV infection or AIDS (34%), neoplastic disease or leukemia (31%), steroids (10%), transplantation (6%). A source of contamination was suspected in only 10.3% of cases, mainly food or intra-familial contamination. Most of the patients had high-grade fever of mean 4 days duration; main clinical manifestations were : enteritis (38.1%), septicemia (33.5%), urinary infection (9.7%), pneumopathy (4%), septic arthritis (4%). Antibiotic therapy was prescribed in 75 % of cases, most often (53%) a combination. The infection was cured in most cases but a failure was evidenced in 24 cases (15.5%). Mortality rate was 12.2% and was mainly related to severe underlying diseases. Positive blood cultures, septicemia and other severe forms of infection, as well as adverse outcome were more frequent in patients with underlying disease. It is concluded that S. dublin presents unique pathogenic features among non typhoidal Salmonellae; it has invasive properties leading with a high frequency to bacteremia and septicemia; it should be considered as an opportunist and it can be difficult to eradicate in immunocompromised hosts, despite regular antibiotic susceptibility.