Incidence, risk factors, microbiology of venous catheter associated bloodstream infections--a prospective study from a tertiary care hospital.

PURPOSE: Central venous catheters (CVCs) though indispensable in current medical and intensive care treatment, also puts patients at risk of catheter related infection (CRI) resulting in increased morbidity and mortality. We analysed the incidence, risk factors, bacteriological profile and antimicrobial susceptibility pattern of the isolates in central venous catheter associated bloodstream infection (CVC-BSI) in the intensive care unit (ICU) patients and studied the formation of biofilm in CVCs.

MATERIALS AND

METHODS

The following case control study included 115 patients with CVC in situ. Quantitative blood cultures (QBC) and catheter tip cultures were performed for the diagnoses. Direct catheter staining was done for an early diagnosis by acridine orange (AO) and Gram staining methods. Biofilm production in catheters was detected by 'tissue culture plate' (TCP) method. The results were analysed using the computer-based program statistical package for the social sciences (SPSS).

RESULTS

In 25/115 patients, definite diagnosis of CVC-BSI was made. The mean age was 48.44 ± 17.34 years (cases) vs 40.10 ± 18.24 years (controls) and the mean duration of catheterisation was 25.72 ± 8.73 days (cases) vs 11.89 ± 6.38 days (controls). Local signs of infection (erythema, tenderness and oozing) were found more significantly in CVC-BSI cases. The AO staining was more sensitive and Gram staining of catheters showed higher specificity. Staphylococcus aureus followed by Pseudomonas aeruginosa and non-albicans Candida were common CVC-BSI pathogens. Multidrug-resistant (MDR) strains were isolated in bacterial agents of CVC-BSI. Non-albicans Candida and Enterococcus faecalis showed strong biofilm production.

CONCLUSION

The incidence of CVC-BSI was 21.73% and the rate was 14.59 per 1000 catheter days. Prolonged ICU stay and longer catheterisation were major risk factors. S. aureus was isolated most commonly in CVC-BSI cases. The menace of multidrug resistance and biofilm formation in CVCs is associated with CVC-BSI.