Changing pattern of antibiotic sensitivity of Salmonella typhi

The emergence of multidrug-resistant Salmonella typhi led to the use of quinolones as the first-line drug in the treatment of adult patients with typhoid fever. However, over the last few years there has been an impression that patients on ciprofloxacin tended to take longer to defervesce. We studied the response and antibiotic sensitivity patterns during 2 time periods to assess the changes that may have occurred.

A retrospective analysis was done of blood culture-positive patients with Salmonella typhi infection during 1991 and 1996-97. The mode of presentation treatment history, antibiotic sensitivity pattern, antibiotics administered, response to therapy and the complications that ensued were studied.

In vitro sensitivity to ciprofloxacin was found to be 100% in both the study groups. It was found that a greater number of patients were sensitive to ampicillin (80%), chloramphenicol (80%) and co-trimoxazole (80%) during 1996-97 as compared to 1991, when sensitivity to ampicillin was 63%, chloramphenicol 65% and co-trimoxazole 65%. The mean (SD) defervescence period in 1991 was 6 (2.3) days and in 1996-97 was 6 (2) days (p > 0.05).

In vitro sensitivity of Salmonella typhi to ciprofloxacin remains 100%. There was an increase in the sensitivity to ampicillin, chloramphenicol and co-trimoxazole which have been rarely used over the past few years. There was no significant difference in the time taken to defervesce between the two study periods.