Enteric fever caused by Salmonella isolates with decreased susceptibility to ciprofloxacin.

With emerging drug resistance, ciprofloxacin became the frontline antibiotic against Salmonella strains causing enteric fevers worldwide. However, strains with decreased susceptibility to flouroquinolones have recently emerged as a problem in our region. Such strains are not detected by the routine disc diffusion method unless a nalidixic acid disc is also used. They are, however, important clinically since they show poor clinical responses and have higher faecal carriage rates following treatment with fluoroquinolones in usual doses. We report the first two cases of such strains in Sri Lanka, both acquired locally. We recommend the routine use of a nalidixic acid disc in sensitivity testing of Salmonella species, causing enteric fever in laboratories not determining minimum inhibitory concentrations (MICs) for fluoroquinolones in order to detect such strains, so that appropriate clinical decisions regarding antibiotic therapy can be made.

Monitoring effectiveness of controlling hospital acquired infections by prevalence surveys.

OBJECTIVE: To determine the effectiveness of control measures for hospital acquired infection (HAI) by prevalence studies. SETTING: National Hospital of Sri Lanka in Colombo (NHSL). STUDY DESIGN AND METHOD: Two prevalence surveys were undertaken, in October 1994 and in July 1997, after implementing infection control measures. The numbers of patients in the two studies were 2563 and 2865. The subjects were assessed for hospital acquired infection through information obtained from case notes and by discussion with ward nursing and medical staff. The changes in infection control activities during this 3-year period included increasing the number of infection control nurses, educational programs to health care workers at all levels, improvements in disposal of clinical waste, implementing published guidelines for use of antibiotics, cannula-site management and urinary catheter care. RESULTS: The prevalence of HAI in the hospital decreased significantly (p < 0.0001) from 13.5% in 1994 to 8.7% in 1997. A significant decrease (p < 0.0001) in infection rates was observed in medical wards, but the decrease in surgical wards and the burns unit did not reach statistical significance. The intensive care units showed a weakly significant increase (p < 0.05) of infection rate attributable to the large number of war injured who needed intensive care. The most significant reduction in rates of infection was seen in wound infection (p < 0.001), respiratory infections (p < 0.01) and in cannula site infections (p < 0.001). CONCLUSION: Implementation of infection control policies can have a significant impact on the prevalence of HAI, and their effectiveness could be measured by repeated prevalence surveys.