Bacteriology and Antibiotic Sensitivity Patterns of Urine in Urology Patients with Indwelling Urinary Catheters at the University Teaching Hospital in Lusaka, Zambia

Abstract

Introduction: Catheter-associated urinary tract infection (CAUTI) is the most common nosocomial infection in hospitals worldwide, and the incidence has been reported to be up to 35%. The growing antibiotic resistance amongst the uropathogens isolated from CAUTI makes it challenging to manage. In Zambia, prolonged catheter use is a burden, particularly in patients awaiting definitive surgery, the elderly and the socioeconomically challenged. Bacterial colonisation following catheterisation is inevitable, with reports estimating the risk to be around 5-10% per day. By day 10, virtually all patients with urinary tract instrumentation have healthcare-associated UTI, with the duration of catheterisation the most important factor. Methodology: The study was a descriptive cross-sectional study conducted at UTH over a period of 10 months from July 2015 to May 2016. The cases were inpatients and outpatients with indwelling catheters in situ for not less than three calendar days. Simple random sampling was used to select candidates who were inpatients awaiting definitive surgery and outpatients in the same category as they attended clinics. Data collection and collection of specimens were done by the principal investigator, which was analysed by the microbiologist based at the UTH microbiology laboratory. The patients were recruited at one point, and the data collection exercise employed a questionnaire to collect socioeconomic demography and clinical information. The variables were collected using the data collection sheet for each participant. The data was then entered into SPSS software to clean and analyse data. The categorical variables were presented as proportions. The main concerns arising during specimen collection were the duration between the time of specimen collection and transfer to and processing at the main laboratory, which was kept within one hour. Specimens received within two hours of the collection were accepted. Results: A total of 228 patients were enrolled from both outpatient and inpatient departments. Approximately 75% yielded growth of bacteria, and 25.0% were negative. The pure growth yielded Klebsiella Pneumoniae 28.0% and E. coli 25.2%, as the most isolated pathogens. The antibiotic susceptibility testing revealed the highest resistance of the above isolates to ampicillin, nalidixic acid, norfloxacin, ciprofloxacin, levofloxacin, and borderline with cotrimoxazole. The organisms were least resistant to amikacin, imipenem, nitrofurantoin, and gentamycin. Acetinobacter and Citrobacter species were also highly resistant to the above drugs with nitrofurantoin in addition but least resistant to ampicillin. Conclusion: The study revealed a high prevalence of CAUTI in the urology section of the UTH, and practices such as poor hand hygiene, open catheter drainage, non-aseptic methods of catheter insertion and poor catheter care are possible contributing factors. There is an association between the insertion of indwelling catheters and subsequent development of CAUTI, and the strongest factors noted are the size of the catheters used and the patient's level of education. High resistance to antibiotics to many organisms of concern was noted.