Enteric Fever Treatment Failures--Reply to Drs. Chandel and Chaudhry.

To the Editor: We are pleased that Drs. Chandel and Chaudhry support our concern that the development of low-level resistance to fluoroquinolone antimicrobial agents in Salmonella enterica serotype Typhi is a threat to health in both developing and developed countries. They cite their article (1) reporting the recent emergence in India of strains of S. Paratyphi A resistant to nalidixic acid and with low-level resistance to ciprofloxacin. This finding has also been observed in the United Kingdom, with [is greater than] 30% of S. Paratyphi A infections in 2000 being caused by strains with decreased susceptibility to ciprofloxacin. Of these strains, only one was also resistant to other antimicrobial agents.

Our findings and those of Chandel and Chaudhry clearly demonstrate the inadvisability of the use of ciprofloxacin in the Indian Subcontinent to treat many human infections, regardless of prescription. To maintain the efficacy of fluoroquinolones in both developing and developed countries, this class of antimicrobial agents must be reserved for treatment of invasive disease and not for prophylaxis. For travelers visiting developing countries, ciprofloxacin must be used only when absolutely necessary and not for treatment of uncomplicated gastroenteritis or for travelers' diarrhea syndromes.

E. John Threlfall and Linda R. Ward
Central Public Health Laboratory, London, United Kingdom

Reference

(1.) Chandel DS, Chaudhry R, Dhawan B, Pandey A, Dey AB. Drug-resistant Salmonella enterica serotype Paratyphi A in India. Emerg Infect Dis 2000;6:420-1.