Predictors for extraintestinal infection of non-typhoidal Salmonella in patients without AIDS

To identify the risks and predictors for extraintestinal infection (EII) in patients with non-typhoidal salmonellosis, we undertook a study of 398 patients with cultures positive for non-typhoidal Salmonella seen at Chang Gung Memorial Hospital and Chang Gung Children's Hospital between November 1993 and October 1994. Salmonella choleraesuis was the most invasive serotype observed. S. panama, S. typhimurium and S. schwarzengrund were the commonest causes of EII among those serotypes usually causing gastroenteritis. Pre-existing underlying disease, particularly immunosuppressive disease, was the most important risk factor that may have predisposed adult patients to have EII. Old age (> or = 60 years) and isolation of invasive serotypes were also frequently associated with EII in adult patients. The characteristics of paediatric patients with a high probability of having EII were: < 3 years of age, abnormal blood test results (a leucocyte count > or = 15,000/mm3 or < 5000/mm3, immature leucocytes > or = 10% of total leucocytes, and a C-reactive protein concentration > or = 50 mg/l); and isolation of invasive serotypes. This information can be an aid to early diagnosis and treatment of EII caused by non-typhoidal Salmonella.