Analysis of a multidrug resistant acinetobacter SPP. outbreak in the intensive care unit of King Edward VIII Hospital.

Abstract

The study arose out of a need to investigate and control a nosocomial outbreak caused by multidrug resistant Acinetobacter spp in the fifteen-bed intensive care unit of King Edward VIII Hospital. Following the discovery of the index case, four other patients were found to have a similar strain of Acinetobacter spp. All fifteen patients in the ward were subsequently screened for the organism. Forty-seven isolates were obtained from 12 patients. Eight of the patients were infected with the organism and six of these eight patients subsequently died. Swabs from the ward environment were also screened for the organism, which was found in patients' baths, suction water and urine collection jars. The outbreak was aborted by the use of strict infection control techniques. Minimum inhibitory concentrations (MICs) of 20 of the 47 isolates were determined for the following antimicrobials: imipenem, ciprofloxacin, gentamicin, amikacin, netilmycin,cefotaxime, ceftazidime and tetracycline. The same 20 isolates were further typed using ribotyping. Seven different antibiogram patterns were obtained using the MIC data. The majority of isolates (11) fit into a Single type, and showed resistance to all drugs tested, except for susceptibility to tetracycline and netilmycin only. Ribotyping revealed 5 different types. There were 9 isolates of ribotype a, 2 of ribotype b, 3 of ribotype c, 5 of ribotype d and 1 of ribotype e. In conclusion, this study describes a nosocomial outbreak with a multidrug resistant Acinetobacter spp. in an intensive care unit. The results showed that there was no correlation between the two typing methods used, ribotyping was more discriminatory than antibiogram types, with the majority of strains belonging to two different ribotypes.