RESUMEN
OBJECTIVE: To compare the frequency of health-care worker (HCW) hand contamination by Escherichia coli versus Klebsiella species after patient care and to determine activities associated with contamination. METHODS: We conducted a prospective observational study at two tertiary-care centres. We observed HCWs caring for patients colonized/infected with E. coli or Klebsiella. HCW hands were cultured before room entry and after patient care. Contamination was defined as detecting E. coli or Klebsiella on HCW hands. Risk factors for contamination were analysed using logistic regression. Patient-to-HCW transmission was confirmed by pulsed-field gel electrophoresis (PFGE). RESULTS: We performed 466 HCW observations: 290 from patients with E. coli, 149 with Klebsiella, and 27 with both species. Eighty-seven per cent of observations (404/464) occurred in patients who had received chlorhexidine bathing within 2 days. HCW hand contamination rates were similar between E. coli (6.2%; 18/290) and Klebsiella (7.4%; 11/149) (p 0.6). High-risk activities independently associated with contamination were toilet assistance (OR 9.34; 95% CI 3.10-28.16), contact with moist secretions (OR 6.93; 95% CI 2.82-17.00), and hygiene/bed-bathing (OR 3.80; 95% CI 1.48-9.80). PFGE identified identical/closely related isolates in the patient and HCW hands in 100% (18/18) of E. coli and 54.5% (6/11) of Klebsiella observations. CONCLUSIONS: We did not find a difference in HCW hand contamination rates between E. coli and Klebsiella after patient care. Hand hygiene should be reinforced after high-risk activities. Discrepancies in matching patient and HCW hand isolates occurred more frequently for Klebsiella than for E. coli; differences in species-level transmission dynamics might exist.