Model-based Assessment of the Effect of Contact Precautions Applied to Surveillance-detected Carriers of Carbapenemase-producing Enterobacteriaceae in Long-term Acute Care Hospitals. (13th September 2019) - Toth, Damon J A
Abstract: Background: An intervention that successfully reduced colonization and infection with carbapenemase-producing Enterobacteriaceae (CPE) in Chicago-area long-term acute-care hospitals included active surveillance and contact precautions. However, the specific effects of contact precautions applied to surveillance-detected carriers on patient-to-patient transmission are unknown, as other, concurrent intervention components or changes in facility patient dynamics also could have affected the observed outcomes. Methods: Using previously published data from before and after the CPE intervention, we designed a mathematical model with an explicit representation of postintervention surveillance. We estimated preintervention to postintervention changes of 3 parameters: β, the baseline transmission rate excluding contact precaution effects; δ b, the rate of a CPE carrier progressing to bacteremia; and δ c, the progression rate to nonbacteremia clinical detection. Results: Assuming that CPE carriers under contact precautions transmit carriage to other patients at half the rate of undetected carriers, the model produced no convincing evidence for a postintervention change in the baseline transmission rate β (+2.1% [95% confidence interval {CI}, −18% to +28%]). The model did find evidence of a postintervention decrease for δ b (−41% [95% CI, −60% to −18%]), but not for δ c (−7% [95% CI, −28% to +19%]). Conclusions: Our results suggest that contact precautions for surveillance-detected CPE carriers could potentially explain the observed decrease in colonization by itself, even under conservative assumptions for the effectiveness of those precautions for reducing cross-transmission. Other intervention components such as daily chlorhexidine gluconate bathing of all patients and hand-hygiene education and adherence monitoring may have contributed primarily to reducing rates of colonized patients progressing to bacteremia. Abstract : We mathematically modeled a bundled intervention that successfully reduced carbapenemase-producing Enterobacteriaceae in long-term acute care hospitals. Results show that contact precautions for surveillance-detected carriers plausibly can explain the observed reduction in carriage prevalence without substantial contribution from other intervention components.