Infections and colonisation of central venous catheters in patients admitted to intensive care units at two tertiary care hospitals

Introduction: Central venous catheters (CVC) are frequently used in modern health care systems. However, CVCs are likely to get colonised with microorganisms, resulting in catheter-related blood stream infections (CRBSI). This study investigated microorganisms causing CRBSI and CVC colonisation, their antibiotic resistance, and factors associated with CRBSI in patients in the intensive care units (ICU) at the Colombo North Teaching Hospital (CNTH) and  Apeksha hospital, Sri Lanka.

Methods: The study included 300 adult patients in ICUs with a CVC in-situ for >48 hours. Blood taken through the CVC, peripheral blood and CVC tips were cultured. Microorganisms were identified and tested for antibiotic susceptibility. Demographic factors were recorded.

Results: Seventeen patients (13.1%) developed CRBSI.  The CRBSI rate was 13.3 per 1,000 catheter days in CNTH while it was 10 (5.9%) cases and 5.2 per 1,000 catheter days in Apeksha hospital. In CNTH, CVC colonisation was detected in 35 (26.9%). Coagulase negative staphylococci (CoNS) were the leading cause of both CRBSI (41%) and colonisation (58%). In Apeksha hospital, Klebsiella sp. (5/10)  were  the predominant pathogens that  caused  CRBSI. Eighty-nine CVCs (52.3%) were colonised by CoNS (58%). In CNTH, CRBSI was detected more in males (14/17) (p<0.05). The majority of microorganisms that caused  CRBSI and CVC colonisation in both hospitals showed resistance to commonly used antibiotics.

Conclusion: The CRBSI rates and the incidences were higher in CNTH. CoNS was the most common  cause of CRBSI in CNTH and Gram negative bacteria in Apeksha hospital. CVC colonisation with CoNS was common in both hospitals. Antibiotic resistance was high among bacteria causing CRBSI and colonisation.