Evaluation of the case prevalence of Extended Spectrum Beta Lactamase- producing Isolates at the Colonial War Memorial Hospital: Risk Factors and Impact on Clinical Outcomes.

Extended-spectrum beta lactamases (ESBLs) confer resistance to 3 rd and 4th generation cephalosporins and monobactams, in addition to the earlier cephalosporins. ESBLs are most common in Klebsiella pneumonia and Escherichia coli, but do occur in other Entero bacteriacae and in Pseudomonas aeruginosa. ESBLs are being increasingly identified in many parts of the world and are now very prevalent in several countries in the Asia-Pacific region.
This was a retrospective study carried out in the Colonial War Memorial Hospital, and the aim of this study was to:
•Determine the prevalence of ESBL-producing organisms in the hospital,
•To evaluate the risk factors for acquisition of these organisms,
•Their impact on clinical outcome.
A total of 82 ESBL-producing isolates were identified, however only 62 where clinical records of patients were able to be retrieved and analyzed. Variables that were considered included age, gender, ethnicity, diabetes, renal failure and malignancy. The risk factors that were analyzed included: presence of a catheter, prior antibiotic use, mechanical ventilation and if a surgical procedure was performed.
Most of the ESBLs were isolated from urine (26, 41.9%) wound and pus swabs, (18, 29%) and (16, 25.8%) respectively. The most common organism isolated was Klebsiella pneumonia (53, 85.5%) followed by Escherichia coli (8, 12.9%).
The highest rates of ESBL-producing organism were isolated from the surgical wards followed by the Children's ward and then the medical wards.
The results of this study have highlighted that ESBLs do exist in our hospital and the figure obtained is somewhat similar to other studies been described.
No doubt, we expect this trend to increase if careful infection control and antibiotic prescribing are not carefully controlled.