Study on Catheter-Associated Urinary Tract Infection (CAUTI): Incidence and Microbiological Profile in a Tertiary Care Hospital in Andhra Pradesh

Background: The etiological agents of Catheter associated urinary tract infection (CAUTI) are sundry and often multidrug resistant. An early, appropriate antimicrobial therapy based on culture sensitivity report and implementation of infection control practices together play a key role in management of CAUTI. Objectives: 1. To find the incidence of CAUTI in intensive care unit (ICU) patients. 2. To identify etiological agents responsible for CAUTI. 3. To determine antimicrobial susceptibility pattern for bacterial agents obtained. Methods: Urine samples from clinically suspected cases of CAUTI were obtained from patients with urinary catheters admitted in ICUs. Urine samples were subjected to wet mount, culture and sensitivity testing. Responsible pathogens and their antimicrobial susceptibility pattern were obtained based on CSLI standards. Results: A total of 640 patients were having indwelling urinary catheter with an aggregate of 5199 catheter days over a period of 6 months. 19 were culture positive out of 45 clinically suspected cases of CAUTI. The CAUTI rate was 3.65 cases per 1000 catheter days. Most predominant etiological agents responsible for CAUTI were Citrobacter species (26.3%) followed by P.aeruginosa (21.1%) and E. coli (21.1%). 2(18.2%) ESBL producing Gram negative bacteriawere obtained among Enterobacteriaciae. The most effective antibiotics were ceftazidime/clavulinic acid, colistin and meropenam for Enterobacteriaciae; piperacillin/tazobactam for P.aeruginosa; linezolid and vancomycin for Enterococcus species. Introduction Nosocomial infections, or hospital-acquired infections (HAI), are important cause of morbidity and mortality in healthcare settings especially among patients admitted in intensive care units(ICUs). Urinary tract infections (UTIs) account for 20-50% of all hospital-acquired infections occurring in the intensive care unit (ICU). Urinary catheterization in itself is a risk factor for Catheter associated urinary tract infection (CAUTI). CAUTI as defined by CDC is an UTI where an indwelling urinary catheter was in place for more than 2 calendar days on the date of event, with day of device placement being Day 1, and an indwelling urinary catheter was in place on the date of event or the day before. If an indwelling urinary catheter was in place for more than 2 calendar days and then removed, the date of event for the UTI must be the day of discontinuation or the next day for the UTI to be catheter-associated. Culture positivity is the said event. Several bacterial species are known to form biofilm on urinary catheters as a survival benefit. The most common pathogens of CAUTI include Escherichia coli, Pseudomonas aeruginosa, Enterococcus species and Candida albicans. Both the microbiological profile and antimicrobial sensitivity pattern vary considerably from time to time and region to region. CAUTI is coupled with prolonged hospital stay among patients and considerable financial burden to both patients and hospitals. Pooled mean CAUTI rate was 0 to 4 per 1000 catheter days as given by National Healthcare Safety Network (NHSN) report of U.S.A. Inappropriate and recurrent use of antibiotics to treat CAUTI, can promote antimicrobial resistance. Therefore evidence based diagnosis of CAUTI and initiation of appropriate antimicrobial therapy based on microbiological test results is necessary in ICU settings. Materials and Methods The present study was carried out in a tertiary care hospital at Visakhapatnam, Andhra Pradesh for a period of 6 months (January 2016 to June 2016). It is a prospective study approved by institutional ethical committee. A total of 640 patients admitted in ICUs were catheterized with indwelling urinary catheter (Foley’s catheter) during the study period. Urinary catheter care bundle was implemented among all catheterized patients as per Healthcare Infection Control Practices Advisory Committee (HICPAC) guidelines. Follow up of catheterized patients was done meticulously on daily basis and observed for local and systemic signs of UTI. On clinical suspicion of UTI in catheterized patients, urine sample was sent to microbiology laboratory along with prompt documentation. Culture positivity obtained in less than 2 calendar days of urinary catheterization was not considered as CAUTI. Sample collection: Fresh urine samples were collected in a sterile, leak-proof universal container from patients under aseptic technique from sampling port of sterile closed urinary drainage system which was transported to the microbiology laboratory for immediate processing. Sreedevi Hanumantha et al. Catheter associated urinary tract infection (CAUTI) Indian J Microbiol Res 2016;3(4):454-457 455 Processing of specimens in laboratory: The urine samples were subjected to direct wet mount and culture using semi-quantitative standard loop technique. Inoculation was done on Cystine Lactose Electrolyte Deficient medium (CLED) and blood agar. Significant count was considered. Discrete bacterial isolates thus obtained were subjected to Gram staining, hanging drop preparation, other necessary tests including biochemical tests for further identification. The species identification of bacterial and fungal isolates was done based on standard laboratory procedures. Kirby-Bauer disc diffusion method was adopted for antimicrobial susceptibility testing using appropriate antimicrobial discs as per CLSI guidelines. Results Indwelling urinary catheter was used in 640 patients admitted in ICUs with catheter days ranging from 5-10 catheter days on an average for each patient. A sum total of 5199 catheter days were obtained in the study period. 45(7.03%) patients developed clinical signs or symptoms of UTI after 2 calendar days from the time of insertion of indwelling urinary catheter. Of 45 urine samples cultured, 19(42.2%) were culture positive and 26(57.8%) showed no evidence of growth. Incidence of CAUTI was 3.65 per 1000 catheter days over a 6 month period. Single significant pathogen with colony count of more than 100000 colony forming units was obtained from each culture positive sample. Table 1: Spectrum of isolates obtained in CAUTI Sl no. Organism No. of isolates 1 Citrobacter species 5 2 Pseudomonas aeroginosa 4