Changing pattern of Clostridium difficile associated diarrhoea in a tertiary care hospital:: A 5 year retrospective study

Background & objectives: Frequent use of broad spectrum antibiotics in hospitalized patients has increased the incidence of Clostridium difficile diarrhoea in recent years. In our tertiary care hospital in north India, C. difficile was responsible for 15 per cent of cases of nosocomial diarrhoea in 1999. A retrospective study was carried out to determine the frequency of C. difficile associated diarrhoea (CdAD) in our hospital, and to assess the effect of awareness among the hospital personnel and control measures taken to present C. difficile infection following the previous report. Methods: A retrospective chart review of all suspected cases of CdAD diagnosed at the hospital from January 2001 to December 2005 was done. Clinical specimens comprised 524 stool samples. All the samples were analyzed for C. difficile using culture and ELISA for toxin A and B. Attempts were made to type isolates using antibiogram, SDS-PAGE, gas liquid chromatography (GLC), PCR for toxin A and B gene fragments and restriction fragment length polymorphism (RFLP). Results: A total of 37 (7.1 %) specimens were positive for C. difficile toxin (11.2 % in 2001, 9.4 % in 2002, 8.6% in 2003, 5% in 2004 and 4% in 2005). The highest number of C. difficile toxin positive cases were from stool samples of patients hospitalized in the haematology/oncology ward (67.5% of all positive cases) followed by gastrointestinal surgery, neurology and nephrology wards. Of the C. difficile toxin positive samples, 15 (41%) were also positive for C. difficile culture. The isolates were grouped in to one, 3 and 5 groups using antibiogram, SDS-PAGE and PCR RFLP respectively. We observed an increase in the number of stool specimens tested for C. difficile infection but a decrease in C. difficile positives. Interpretation & conclusions: A decrease in the number of C. difficile positive cases were noted during the 5 year study period though number of samples tested was increased. This may be due to stringent surveillance and an improved antibiotic policy followed in the hospital.