Prevalence and risk factors for meticillin-resistant Staphylococcus aureus in an acute care hospital and long-term care facilities located in the same geographic area.

UNLABELLED: To determine the prevalence and risk factors (RF) for methicillin-resistant Staphylococcus aureus (MRSA) during stay in 1 acute care hospital (ACH) and 4 long-term care facilities (LTCF). After obtaining the informed consent, nasal and skin ulcer swabs were taken and a survey was conducted to determine RF for MRSA. Six hundred and ninety nine patients were included, 413 LTCF and 286 ACH patients and MRSA prevalence were 22.5% and 7.3% respectively. MRSA was located in the nares, skin ulcers, and in both in 61.4%, 21.1%, and 17.5%. Among MRSA carriers, 81% of the ACH and 66.7% of the LTCF patients were only colonized. The multivariate analysis for the ACH revealed the following factors to be associated with MRSA: referral from an LTCF (OR 4.84), pressure ulcers (OR 4.32), a Barthel score < 60 (OR 2.60), and being male (OR 5.21). For the LTCF: urinary catheterisation (OR 3.53), pressure ulcers (OR 2.44), other skin lesions (OR 2.64), antibiotic treatment in ≤ 6 months, (OR 2.23), previous MRSA colonization (OR 2.15), and a Barthel score <20 (OR 1.28). Molecular typing identified 2 predominant clones Q, P, present in all centres. No relationship was found between clones and antibiotic susceptibility. IN CONCLUSION: MRSA prevalence is high in all centres but is 3 times greater in LTCF. The risk factors most strongly associated with MRSA were pressure ulcers and a stay in an LTCF. We propose preventive isolation in these cases.

A community outbreak of Legionnaires' disease: evidence of a cooling tower as the source.

A community outbreak of Legionella pneumonia in the district of Cerdanyola, Mataró (Catalonia, Spain) was investigated in an epidemiological, environmental and molecular study. Each patient was interviewed to ascertain personal risk-factors and the clinical and epidemiological data. Isolates of Legionella from patients and water samples were subtyped by pulsed-field gel electrophoresis. Between 7 August and 25 August 2002, 113 cases of Legionella pneumonia fulfilling the outbreak case definition criteria were reported, with 84 (74%) cases being located within a 500-m radius of the suspected cooling tower source. In this area, the relative risk of being infected was 54.6 (95% CI 25.3-118.1) compared with individuals living far from the cooling tower. Considering the population residing in the Cerdanyola district (28,256 inhabitants) as a reference population, the attack rate for the outbreak was 399.9 cases/100,000 inhabitants, and the case fatality rate was 1.8%. A single DNA subtype was observed among the ten clinical isolates, and one of the subtypes from the cooling tower matched exactly with the clinical subtype. Nine days after closing the cooling tower, new cases of pneumonia caused by Legionella ceased to appear. The epidemiological features of the outbreak, and the microbiological and molecular investigations, implicated the cooling tower as the source of infection.