Background: Children with enteric fever or severe salmonella infections are usually treated with beta-lactam antibiotics, particularly ceftriaxone. Due to their poor penetration into cells, beta-lactam antibiotics, even if active in vitro, are sometimes clinically ineffective because they cannot reach the intracellular sites of Salmonella multiplication.
Objectives: To evaluate in a retrospective study usefulness, efficacy and safety of oral ciprofloxacin in patients with severe salmonellosis and clinical failure of ceftriaxone or beta-lactam antibiotics.
Patients and methods: From July 1, 1995 to 2000, the bacteriology laboratory of a French pediatric hospital had identified 215 patients aged between 1 month and 15 years with positive blood or stools for Salmonella sp, 113 of them requiring hospitalization due to their clinical symptoms. Three were excluded for sickle-cell disease or poor nutritional status. None of the 110 strains (including 4 S. typhi, 51 S. typhimurium, 25 S. enteritidis, 6 S. hadar and 5 S. heidelberg) isolated was resistant to ceftriaxone or ciprofloxacin. Forty-one of the 110 strains (37.3%) produced a beta-lactamase. Twelve patients had a rapid recovery without antibiotic treatment, and 98 (mean age 3.9 years) were given antibiotics (ceftriaxone in 91 and amoxicillin in 7) for dysentery (43%), shock (15%) or persistent high fever and severe diarrhea (42%).
Results: In 72 children (mean age = 3.6 years) ceftriaxone treatment (amoxicillin in 5) for 5 or 7 days was rapidly effective: apyrexia was obtained in 1.5 day after the start of treatment and the number of stools per day was 4 or less in 2.2 days. Two to 3 weeks after clinical recovery, asymptomatic carriage was present in 22/38 patients. In the 26 other patients ceftriaxone (amoxicillin in 2) treatment was clinically ineffective, despite good in vitro activity, and was switch for oral ciprofloxacin (20 mg kg(-1) d(-1), 5 days) after 2 to 7 days of lasted fever and/or severe diarrhea. Clinical improvement with ciprofloxacin was obtained in less than 48 h. The strains involved in these 26 patients included the 4 S. typhi and 15 S. typhimurium (P < 0.05), 13/15 (P < 0.01) producing beta-lactamase. Asymptomatic carriage was found in 5/22 patients (P < 0.05) after recovery. None of the patient treated with ciprofloxacin had side effect.
Conclusion: In severe salmonellosis, the clinical failure of treatment with ceftriaxone is not rare, particularly in S. typhimurium producing beta-lactamase infection and short treatment with oral ciprofloxacin is safe and allows to obtain a rapid recovery.