Epidemiology of methicillin-susceptible Staphylococcus aureus in a university medical center day care facility.

BACKGROUND: Few data are available on methicillin-susceptible Staphylococcus aureus (MSSA) colonization in day care. We performed a study in a child care center on a medical university campus to study the epidemiology of MSSA in this population. METHODS: A cross-sectional study was done on 104 day care attendees and 32 adult employees of the child care center. Swab samples were taken from the nose, oropharynx, axilla, groin, and perirectal area of children, from the nose and oropharynx of employees, and from the environment. Parents and employees completed questionnaires. Swabs were placed in broth, then plated on agar and identified as MSSA by routine methods. Molecular typing was performed. RESULTS: The prevalence of MSSA was 21.15% in children and 28.13% in employees. MSSA was found in 8.72% of environmental samples. Univariate analysis identified 3 risk factors and 5 protective factors for MSSA colonization. In multivariable analysis, only 2 variables remained significantly related to MSSA colonization, with older age remaining as a risk factor and receipt of beta-lactams approaching significance as being protective. Many of the isolates were indistinguishable by molecular typing. CONCLUSIONS: The prevalence of MSSA colonization in children and care providers in a university medical center child care center is similar to that of the general population. Children colonized with MSSA tended to be older and to have received fewer courses of antibiotics than children who did not have MSSA. The relatedness of many of the isolates indicates that transmission of MSSA occurred at this child care center.

Epidemiology of methicillin-resistant Staphylococcus aureus in a university medical center day care facility.

OBJECTIVE: Few data are available on methicillin-resistant Staphylococcus aureus (MRSA) colonization in day care. We performed a study in a medical university child care center to study the epidemiology of MRSA in this population. DESIGN: Survey. SETTING: A child care center on the campus of a university medical center. METHODS: One hundred four children who attended the child care center and 32 employees gave samples that were cultured for MRSA. Seventeen household members of the children and employee found to be colonized with MRSA also gave samples that were cultured. Parents and employees completed questionnaires about demographic characteristics, medical conditions and treatments, and possible exposure risks outside the child care center. In addition, 195 environmental samples were taken from sites at the childcare center. Isolates were analyzed for relatedness by use of molecular typing, and statistical analysis was performed. RESULTS: The prevalence of MRSA in the children was 6.7%. One employee (3.1%) was colonized with MRSA. Cultures of samples given by 6 of 17 (35.3%) family members of these children and the employee yielded MRSA. MRSA was recovered from 4 of 195 environmental samples. Molecular typing revealed that many of the MRSA isolates were indistinguishable, and 18 of the 21 isolates were community-associated MRSA. Multivariable analysis revealed that receipt of macrolide antibiotics (P = .002; odds ratio, 39.6 [95% confidence interval, 3.4-651.4]) and receipt of asthma medications (P = .024; odds ratio, 26.9 [95% confidence interval, 1.5-500.7]) were related to MRSA colonization. CONCLUSIONS: There was a low prevalence of MRSA colonization in children and employees in the child care center but a higher prevalence of colonization in their families. Molecular typing showed that transmission of MRSA likely occurred in the child care center. The use of macrolide antibiotics and asthma medications may increase the risk of MRSA colonization in this population.

A changing pattern of infection after major vascular reconstructions.

Wound and graft infection can occur in more than 40% of patients undergoing vascular reconstructions for peripheral arterial disease (PAD). A recent increase in the frequency and severity of infections, as well as a change in the microorganisms recovered, led us to undertake a retrospective case-controlled study of wound/graft infections at this institution. The medical records of all patients undergoing vascular reconstruction for PAD during the previous 36 months were reviewed. Patient demographics, graft location and conduit, infection location, causative microorganisms, and factors potentially associated with development of infection were recorded. Infections were classified according to a modification of the CDC criteria into superficial incisional, deep incisional, or involving the graft (body only, anastomosis without disruption, or anastomosis with disruption). Univariate and multivariate regression analyses were used to identify factors associated with the development of infection. Four hundred ten (84 aortic, 41 extraanatomic, and 285 infrainguinal) revascularization procedures were performed in 217 men and 193 women with a mean age of 62 years (range 43-88). The infection rate for the entire group was 11.0% (45/410). Eighty percent (36/45) occurred after infrainguinal reconstructions and 64% (29/45) of the infections involved the groin incision. Direct involvement of the graft occurred in 67% (30/45), and 27% (12/45) presented with anastomotic disruption. Of the infrainguinal infections, in situ and prosthetic reconstructions were associated with a significantly higher rate of infection than reversed vein grafts tunneled anatomically (p <0.001, chi-square analysis). Patients with nonautogenous grafts (24 expanded polytetrafluoroethylene and 2 bovine) presented with more advanced infections involving the graft (20/26 procedures) and were more likely to present with anastomotic disruption (11/26). Staphylococcus aureus was isolated in the majority of infections (64%) and in all cases involving graft disruption. Multivariate regression analysis identified the following factors associated with development of infection: previous hospitalization (p = 0.03), a younger age (p = 0.047), and the presence of a groin incision (p = 0.04). Twenty-five percent of graft infections resulted in major amputation, and 11% of patients with graft infection died as a result. The incidence, morbidity, and mortality of infections in vascular reconstructions for PAD are increasing dramatically, particularly in infrainguinal reconstructions involving groin incisions. Perioperative antibiotic selection should be modified to include coverage for all Staphylococcal subspecies and hospitalization before surgical procedures should be avoided.

Effect of gastrointestinal bleeding and oral medications on acquisition of vancomycin-resistant Enterococcus faecium in hospitalized patients.

There has been minimal investigation of medications that affect gastrointestinal function as potential risk factors for the acquisition of vancomycin-resistant enterococci (VRE). We performed a retrospective case-control study, with control subjects matched to case patients by time and location of hospitalization. Strict exclusion criteria were applied to ensure that only case patients with a known time of acquisition of VRE were included. Control patients were patients with > or =1 culture negative for VRE. The risk factors identified were use of vancomycin (odds ratio [OR], 3.2; 95% confidence interval [CI], 1.7-6.0; P=.0003), presence of central venous lines (OR, 2.2; 95% CI, 1.04-4.6; P=.04), and use of antacids (OR, 2.9; 95% CI, 1.5-5.6; P=.002). Two protective factors included gastrointestinal bleeding (OR, 0.26; 95% CI, 0.08-0.79; P=.02) and use of Vicodin (Knoll Labs; hydrocodone and acetaminophen; OR, 0.93; 95% CI, 0.90-0.97; P=.0003). Changes in gastrointestinal function, whether due to bleeding or to the effects of oral medications, may affect whether patients become colonized with VRE.