Invasive non-typhoidal salmonellosis in immunocompetent infants and children.

OBJECTIVE: To investigate the extraintestinal manifestations of non-typhoidal Salmonellae (NTS) infection in immunocompetent infants and children. METHOD: The study took place at the University General Hospital at Heraklion, Crete. Over a 10-year period from 1993-2002 we studied 1087 patients, of whom 443 were children less than 14 years old, with a culture-proven diagnosis of NTS infection. Stool and blood cultures were routinely obtained in patients presenting with fever and diarrhea. The cases of invasive infection in otherwise well children, including bacteremia and/or extraintestinal focal infections were further analyzed. RESULTS: Invasive cases were less common in children than adults (4.06% vs. 8.7%; relative risk 0.467; 95% confidence intervals (CI) 0.279-0.784; p=0.0033). Furthermore, invasive cases were much less common in the otherwise well than in immunocompromised children (3.5% vs. 21.4%; relative risk 0.163; 95% CI 0.053-0.500; p=0.0008). The 15 otherwise well children with invasive NTS infection were aged from 3 weeks to 7.5 years, and nine were aged less than 12 months. Among them, 11 presented with bacteremia, and four with focal extraintestinal infections (rectal abscess, deep neck abscess, urinary tract infection, elbow arthritis). Salmonella enterica subsp. enterica serovars Enteritidis and Virchow were the most common invasive serotypes. All invasive strains were susceptible to beta-lactams including ampicillin, and to cotrimoxazole. All patients made a complete recovery with intravenous antibiotics and did not present with relapses or major infections during long-term follow-up. CONCLUSION: Invasive non-typhoidal salmonellosis in immunocompetent children is less frequent than in both immunocompromised children and in adulthood. However, invasive cases may well occur in otherwise healthy children, especially during infancy. In these patients, prompt appropriate treatment leads to favorable outcomes.