Impact of different carbapenemase-producing Enterobacterales screening strategies in a hospital setting.

ABSTRACT

BACKGROUND: The spread of carbapenemase-producing Enterobacterales (CPE) is a global health problem. Gastrointestinal tract carriage makes faeces or rectal swabs the recommended screening methods. AIM: To assess the impact of three laboratory screening strategies for CPE on positivity rates and infection prevention and control in a hospital setting in North West England from 2015 to 2017. METHODS: In a retrospective study, time to CPE-positive and -negative results, number of new CPE-positive patients identified, and number of hospital bed-days lost/wards affected were measured for each of three CPE screening strategies; culture plus phenotypic tests, culture plus polymerase chain reaction (PCR), and PCR only (phases 1, 2 and 3, respectively). FINDINGS: The fastest time to CPE results was PCR only (median 4.0 h), then culture plus PCR (median 47.6 h), then culture plus phenotypic tests (median 49.8 h) (P < 0.001). The mean numbers of hospital bed-days lost per month decreased between phases 2 and 3 (P = 0.01). The mean number of wards/units affected by CPE increased from phase 1 (2.57) to phase 2 (7.71), then decreased in phase 3 (3.86). The percentage positivity rate for phases 1, 2, and 3 were 2.01, 1.38, and 1.55 respectively. From May to October, the number of new CPE-positive patients was lower for phases 1 and 3 than for phase 2. During all three phases there was a peak in the number of newly identified CPE carriers in August. CONCLUSION: This study provides evidence that using a rapid PCR to screen rectal or faeces swabs enables more timely infection prevention and control measures when compared with culture-based methods. A reduction in bed-days lost due to CPE was observed when rapid molecular screening was introduced.