Microbial burden on environmental surfaces in long-term care facilities: a quantitative analysis.

Background: We conducted a quantitative analysis of the microbial burden and prevalence of epidemiologically important pathogens (EIP) found on long-term care facilities (LTCF) environmental surfaces.

Methods: Microbiological samples were collected using Rodac plates (25cm2/plate) from resident rooms and common areas in five LTCFs. EIP were defined as MRSA, VRE, C. difficile and multidrug-resistant (MDR) Gram-negative rods (GNRs).

Results: Rooms of residents with reported colonization had much greater EIP counts per Rodac (8.32 CFU, 95% CI 8.05, 8.60) than rooms of non-colonized residents (0.78 CFU, 95% CI 0.70, 0.86). Sixty-five percent of the resident rooms and 50% of the common areas were positive for at least one EIP. If a resident was labeled by the facility as colonized with an EIP, we only found that EIP in 30% of the rooms. MRSA was the most common EIP recovered, followed by C. difficile and MDR-GNR.

Discussion: We found frequent environmental contamination with EIP in LTCFs. Colonization status of a resident was a strong predictor of higher levels of EIP being recovered from his/her room.