Environmental reservoirs of methicillin-resistant Staphylococcus aureus in isolation rooms: correlation with patient isolates and implications for hospital hygiene

Strategies to control and prevent the spread of methicillin-resistant Staphylococcus aureus (MRSA) include early identification of positive patients through screening, patient isolation, hand hygiene, nasal and skin decontamination, and the adequate cleaning and decontamination of clinical areas. However, many national and other guidelines provide few details on environmental decontamination regimens, partly because the role of the environment in the spread of MRSA is not well documented. We prospectively studied the environment of the isolation rooms of 25 MRSA patients for up to four weeks, sampling horizontal surfaces and the air using settle plates as well as an air sampler, while continuing regular daily cleaning according to the hospital protocol. We then typed 20 patient isolates and the corresponding environmental isolates (N=35) to assess the similarity of strains. A high proportion of samples were positive for MRSA; 269/502 (53.6%) surface samples, 70/250 (28%) air samples and 102/251 (40.6%) settle plates. Over half of the surface samples taken from the beds and the mattresses were positive for MRSA. Identical or closely related isolates were recovered from the patient and their environment in 14 (70%) patients, suggesting possible environmental contamination of the isolation rooms, possibly contributing to endemic MRSA. More effective and rigorous use of current approaches to cleaning and decontamination is required as well as consideration of newer technologies to eradicate MRSA and other hospital-acquired pathogens.

Implications of colonization of vancomycin-resistant enterococci (VRE) in renal dialysis patients. Learning to live with it?

Vancomycin-resistant enterococci (VRE) commonly colonize, but less frequently infect, debilitated patients, such as those on chronic renal dialysis. The emergence of VRE amongst our cohort of renal replacement therapy patients posed considerable challenges in our attempts to prevent spread. Although 60 of 451 (13%) patients became colonized, only two patients required systemic antibiotics for confirmed or suspected invasive infection. Mortality and inpatient stay was greater in VRE-positive compared with VRE-negative patients (50% versus 10%) and patients who were screened on three or more occasions were likely to remain positive (e.g. 56% of patients screened on six occasions were positive). The application of recommended guidelines for the control of VRE, however, severely disrupted our renal dialysis programme and therefore had to be abandoned. As patients on renal dialysis are more likely to acquire VRE, remain colonized, require antibiotics and require regular inpatient or outpatient care more frequently than other patients, control measures should be adapted to minimize spread but not disrupt important and essential medical services.