CT colonography and transient bacteraemia: implications for antibiotic prophylaxis.

ABSTRACT

OBJECTIVES: To determine the prevalence of transient bacteraemia after CT colonography (CTC). METHODS: Blood cultures were obtained at 5, 10 and 15 min after CTC from 100 consecutive consenting patients. Blood samples were cultured in both aerobic and anaerobic media and positive blood culture samples were analysed by a microbiologist. RESULTS: Blood culture samples were positive for growth in sixteen patients. All positive blood culture samples were confirmed skin contaminants. There were no cases of significant bacteraemia. The estimated significant bacteraemia rate as a result of CTC is 0-3.7%, based on 95% confidence intervals around extreme results using Wilson's score method. CONCLUSIONS: American Heart Association and National Institute for Clinical Excellence guidelines advise that antibiotic prophylaxis before lower gastrointestinal endoscopy is not indicated in patients with at risk cardiac lesions (ARCL) as the risk of a transient bacteraemia leading to infective endocarditis is low. These data show that the prevalence of transient bacteraemia after CTC is also low. It follows that patients with ARCL do not require antibiotic prophylaxis before CTC.