Salmonella infection in systemic lupus erythematosus

Patients with systemic lupus erythematosus (SLE) are susceptible to infections, notably salmonellosis. We report 37 cases of salmonella infection in 24 patients with SLE. These cases were detected in a group of 770 patients with SLE. All the patients were women, with a mean age of 25.6 years. At the onset of salmonella infection, 81% were taking prednisolone and 27% were taking cytotoxic drugs. Renal involvement was present in 75% of patients, which was approximately the same as in other SLE patients. Bacteremia, arthritis, osteomyelitis and rare manifestations of salmonellosis, including pulmonary and urinary tract involvement, were encountered. Diagnosis was based on isolation of the microorganism, mostly from blood cultures. Salmonella species other than typhi and paratyphi were often responsible. Widal agglutination test was positive in less than half the cases, and leukopenia was not seen frequently. Recurrence of infection in 29% of the patients and the high mortality rate (28.5%), despite the conventional period of appropriate antimicrobial treatment, show a poor prognosis of salmonellosis in SLE patients. This special picture of salmonellosis argues for a much longer period of treatment in these patients.