Prevalence Of MRSA Colonization Research Articles

P18 Prevalence and risk factors for nasal colonization with MRSA among children attending immunization in Port Harcourt, Nigeria

Background Staphylococcus aureus is a bacterial agent commonly found on the skin and anterior nares of healthy individuals. There has been an increase in the carriage of MRSA globally. Nasal MRSA colonization is a public health problem because it is a significant risk factor for staphylococcal infection. This study explores the prevalence, antibiotic susceptibility profile and risk factors for nasal colonization of healthy children under 5 years old attending immunization.MethodsNasal swabs were collected from 176 healthy children 0–60 months old, attending routine immunization in Port Harcourt. Questionnaires covering demographic information and potential risk factors were administered to caregivers of the children. Collected samples were tested for the presence of MSSA and MRSA. Antibiotic susceptibility testing was carried out on all MSSA and MRSA samples.ResultsThe prevalence of MSSA and MRSA were 10/176 (5.68%) and 48/176 (27.3%), respectively. The MDR rate among the 58 S. aureus samples was 53/58 (91.38%). Children who had an ear infection in the preceding 1 month were at a higher risk of being colonized with MRSA at P = 0.048 (95% CI). There was also a significant association P = 0.036 (95% CI) between the educational status of mother and nasal colonization, with higher educational status reducing the chances of association.ConclusionsThere is a rising prevalence of MRSA colonization and MDR strains. A history of ear infections and a poor level of education of the mother were identified as significant risk factors for MRSA colonization.Table 1.Association between potential risk factors and MRSA carriageFactorsMRSAχ2 P valuepositivenegativeHospitalization0.3770.539f Yes01 No48127Hospital visit0.1400.708 Yes511 No43117RTI0.8630.353 Yes2474 No2454Ear infection4.8600.048* f Yes42 No44126Antibiotic use1.3750.241 Yes935 No3993Family health worker0.3040.582 Yes510 No43118Smoker1.6380.243f Yes213 No46114*Significant at 95%; fFisher's exact test.

79. Clinical Utility of Methicillin-Resistant Staphylococcus aureus (MRSA) Nasal PCR Assays Beyond Respiratory Infections

BackgroundEmpiric use of vancomycin is common in clinical practice. Currently there is strong evidence to support the use of MRSA nasal screening to predict the absence of MRSA in respiratory infections; however, minimal data exists regarding its utility as a de-escalation tool beyond pulmonary indications. Furthermore, MRSA nasal PCR has been shown to be a more efficient way to detect the presence of MRSA colonization than traditional culture methods. The purpose of this study was to evaluate the correlation between results of MRSA nasal PCR assays and blood or bone/soft tissue cultures.MethodsThis was a retrospective study of patients who presented to any of three hospitals part of an integrated health system in Des Moines, Iowa, from March 1, 2019 to February 29, 2020. Included patients were those who underwent MRSA nasal PCR screening and had a clinical culture (blood, bone, tissue, deep podiatric wound, joint aspirate, or synovial fluid) obtained within 3 days of the MRSA nasal PCR. Data on age, sex, diabetes mellitus and dialysis were collected. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for all cultures, and blood and bone/soft tissue cultures separately were estimated. ResultsA total of 1989 patients were included in the study. Of these patients, 1953 patients had a blood culture obtained and 171 patients had a bone/soft tissue culture obtained. The median age was 66 years, and 1086 (54.6%) patients were male. At baseline, 33.1% and 3.8% of patients had diabetes or were on dialysis, respectively. The overall prevalence of MRSA colonization was 12.3%. The sensitivities of the MRSA nasal PCR screening were 67.5% for all clinical cultures, 81.8% for blood cultures, and 55% for bone/soft tissue cultures. Specificities were 88.8%, 88.5%, and 92.7% for all cultures, blood cultures, and bone/soft tissue cultures, respectively. The PPVs were 11%, 7.5%, and 50% for all cultures, blood cultures, and bone/soft tissue cultures, respectively, and the NPVs were 99.3%, 99.8%, and 92.7%, respectively.ConclusionMRSA nasal PCR screening showed high NPV across blood and bone/soft tissue cultures. These results indicate the clinical utility of MRSA nasal PCR assays beyond respiratory infections and can further support antimicrobial stewardship activities.Disclosures All Authors: No reported disclosures

Prevalence of methicillin-sensitive, methicillin-resistant Staphylococcus aureus, and extended-spectrum beta-lactamase-producing Escherichia coli in newborns: a cross-sectional study

Background The prevalence of antimicrobial-resistant bacteria and methicillin-sensitive Staphylococcus aureus (MSSA) in healthy newborns and the role of maternal transmission are scarcely discussed. Objectives The objective of this study was to evaluate the prevalence of MSSA, MRSA, and ESBL among healthy newborns. Additionally, mother-to-newborn transmission rates were investigated as well as antibiotic susceptibility of MSSA, MRSA, and ESBL isolates. Methods Swabs of 658 newborns and their mothers were collected to investigate the presence of MSSA, MRSA, and ESBL. Swabs were taken from the nose and umbilicus immediately after birth. Additional swabs were taken from the nose, perianal area, and umbilicus 3 days after birth. Samples were screened and further characterized using culture and molecular methods. Results Prevalence of MSSA, MRSA, and ESBL colonization was 10.9, 0.5, and 2.6%, respectively. There was no association between the colonization status of the newborn and infections at any time point. Mother-to-newborn transmission rates (confirmed by PFGE) were 53.6% for MSSA/MRSA and 100% for ESBL. Maternal carriage of MSSA, MRSA, or ESBL was a risk factor for colonization of the newborn. Some isolates were resistant to the antibiotics recommended for therapy, including clindamycin and daptomycin for MSSA/MRSA isolates and ertapenem, fosfomycin, and tigecyclin for ESBL isolates. Conclusion No association between infections and the newborns’ colonization status could be detected. Maternal colonization played an important role in newborn colonization, but not every case of colonization could be explained by mother-to-newborn transmission. General screening of pregnant women and healthy newborns in the absence of other risk factors is not necessary. To prevent the possibility of transmission in the healthcare setting, professionals, pregnant women, parents, hospital visitors, and obstetricians should receive regular training on appropriate hygiene measures. With regard to the emergence of resistance to recommended antibiotics, an antibiogram should be conducted before treating MSSA/MRSA/ESBL infections to ensure the efficacy of the antibiotics.

MRSA colonization and acquisition in the burn unit: A systematic review and meta-analysis

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is one of the most commonly encountered bacteria in the burn unit. In order to investigate the magnitude of this challenge, we assessed the prevalence of MRSA colonization on admission and the incidence of MRSA acquisition within burn units. MethodsWe searched PubMed and EMBASE for studies reporting MRSA colonization among patients admitted in burn units. ResultsWe identified 16 articles that fulfilled our inclusion criteria and found an overall pooled prevalence of MRSA colonization upon the first 72 h of admission (colonization on admission) to the burn unit of 4.1% (95% CI: 2.7%–5.7%). MRSA acquisition in studies without a decolonization protocol was 21.2% (95% CI: 13.2%–30.5%) with a statistically significant downward trend over the years. Studies that implemented a decolonization protocol yielded a MRSA acquisition incidence rate of 4.5% (95% CI: 0.9%–10.6%). MRSA acquisition was higher among patients that have had inhalation injury (OR 3.96, 95% CI: 2.51–6.23), flame burns (OR 1.85, 95% CI: 1.25–2.73), or ICU admission (OR 3.12, 95% CI: 2.18–4.47). ConclusionOur study yielded that among burn victims, MRSA colonization prevalence on admission is not negligible and the risk of becoming MRSA colonized during hospitalization is higher when no decolonization protocols are implemented. Flame burns, admission to ICU, and inhalation injury were found to be associated with MRSA acquisition.

159. Genomic Epidemiology of MRSA at Intake to a Large Inner-City Jail: Evidence for Community Transmission Networks?

BackgroundUSA300 is endemic in the community, with congregate settings potentially facilitating spread. The impact of community MRSA transmission networks on importation of MRSA into urban jails is unknown. We examined MRSA colonization isolates entering the jail and determined whether there are community transmission networks for MRSA that precede incarceration.MethodsHIV-infected and HIV-negative males incarcerated at the Cook County Jail were enrolled within 72 hours of intake. Surveillance cultures (nares, throat, and groin) were collected to determine prevalence of MRSA colonization. A survey was administered to identify predictors of colonization. Whole-genome sequencing (WGS) and phylogenetic analysis were integrated with epidemiologic data to identify community transmission networks.ResultsA total of 800 males were enrolled (83% AA and 9% Hispanic); 58% were HIV-infected. The prevalence of MRSA colonization at intake was 19%. In multivariate analysis, methamphetamine use (METH), unstable housing, and prior jail incarceration were significant predictors of MRSA. Among HIV patients, injection drug use and HIV care at outpatient Clinic A that emphasize comprehensive care to the LGBTQ community were significant predictors of MRSA. Of the 31 (45%) patients with care at Clinic A, 14 had MRSA colonization. We sequenced 145 isolates from unique individuals, with 102 and 13 closely related to USA300 and USA500 reference genomes, respectively. USA300 strains from intake were diverse (median pairwise SNV distance = 109), with several small clusters noted. WGS revealed the high prevalence of MRSA in Clinic A was not due to clonal spread but rather an intermingling of distinct community transmission networks (strains were highly diverse; median pairwise SNV distance = 410). We did identify a 13-member community transmission network underlying spread of USA500 (figure). Members of this network were more likely to be HIV-infected (P < 0.004), MSM (P < 0.001), and METH (P < 0.001).ConclusionA high proportion of individuals enter jail already colonized with MRSA and colonization risk factors provide clues to community reservoirs for MRSA. WGS extended epidemiologic analysis and revealed community transmission networks that could be a potential focus for an intervention. Disclosures All authors: No reported disclosures.

1229. Prevalence and Acquisition of MRSA in Females During Incarceration at a Large Inner-City Jail

BackgroundUSA300 MRSA is endemic in the community, with congregate settings such as urban jails potentially facilitating spread. It has been reported previously that males have a higher risk for MRSA carriage and bacteremia than females. However, it is unclear if there is differential risk for MRSA based on gender in high-risk populations. We determined the prevalence of MRSA colonization at jail entrance in females and defined an acquisition rate during incarceration.MethodsFemales incarcerated at the Cook County Jail, one of the largest US single-site jails, were enrolled within 72 hours of intake. Surveillance cultures (nares, throat, groin) were collected to determine prevalence of MRSA colonization. A survey was administered to identify predictors of colonization. Detainees in jail at Day30 had cultures repeated to determine MRSA acquisition. Univariate and multivariate analyses were performed to identify predictors of MRSA colonization.Results250 women were enrolled (70% AA, 15% Hispanic) with 70% previously in jail (21% in the past 6 months). The prevalence of MRSA colonization at intake was 20% (50/250), with 42% of those colonized solely in the throat or groin. This intake prevalence is comparable to the 19% for male detainees in a parallel study. 9% (2/23) of initially negative women who remained in jail for 30 days acquired MRSA; five remained colonized and no one lost colonization. Univariate predictors (table) of MRSA at entrance to the jail were: illicit drug use (including using needles), unstable housing, engaging in anal sex, and recent exchange of sex for drugs/money. Women who exchange sex for drugs/money (vs. not) reported higher rates of needle use (35% vs. 4%, P < 0.001) and unstable housing (80% vs. 20%, P < 0.001). With multivariate adjustment for race/ethnicity, needles for illicit drugs was a significant predictor of MRSA (OR 5.89, 95% CI, 1.66, 20.94, P = 0.006).ConclusionWe found that a high proportion (20%) of females entered jail colonized with MRSA, comparable to rates in males, suggesting that previously reported gender disparities in MRSA may not exist in high-risk populations. Entrance colonization risk factors suggest high-risk activities or venues in the community, with potential for directing gender-specific interventions. Disclosures All authors: No reported disclosures.

Prevalence of methicillin-resistant Staphylococcus aureus colonization in individuals from the community in the city of Sao Paulo, Brazil.

ABSTRACT Staphylococcus aureus (SA) is a commensal habitant of nasal cavities and skin. Colonization by community-acquired methicillin-resistant SA (CA-MRSA) is associated with infections in patients who have not been recently hospitalized. The aim of this study is to determine the prevalence of MRSA colonization in an outpatient population, currently unknown in Brazil. Three-hundred patients or caregivers from two teaching hospitals were included. A questionnaire was applied and nasal swabs were obtained from patients. Swabs were inoculated in brain heart infusion (BHI) with 2.5% NaCl and seeded in mannitol. Suspicious colonies were subjected to MALDI-TOF MS Microflex™ identification. Antimicrobial susceptibility test for oxacillin was performed for SA-positive samples by microdilution. Polymerase chain-reactions for detection of mecA and coA genes were performed for resistant samples. Data about MRSA carriers were compared with non-carriers. There were 127 S. aureus isolates, confirmed by MALDI-TOF. Only seven (2.3%) were MRSA and positive for mecA and coA genes. Factors associated with MRSA carriage were African ethnicity, skin diseases or antibiotic use. The majority of them were from Dermatology clinics. Prevalence of MRSA colonization in individuals from the community was low in our study (2.3%). This finding raises the hypothesis of inter-household transmission of SA, although we did not find any association between MRSA-colonization and the shared use of personal objects. Given the low prevalence of MRSA carriers observed, empirical antimicrobial coverage for MRSA in community-acquired infections should be not necessary.

Prevalence and Acquisition of MRSA During Incarceration at a Large Inner-city Jail

BackgroundUSA300 MRSA is endemic in certain communities, with congregate settings such as urban jails potentially facilitating spread. The extent of MRSA transmission in jail is unclear, a controversy that impacts prevention strategies. We determined the prevalence of MRSA colonization at jail entrance and defined the acquisition rate during incarceration.MethodsMen incarcerated at the Cook County Jail, one of the largest US single-site jails, were enrolled within 72 hours of intake. Surveillance cultures (nares, throat, groin) were collected to determine prevalence of MRSA colonization. A survey was administered to identify predictors of colonization. Detainees still in jail at Day30 had cultures repeated to determine MRSA acquisition rate. Univariate and multivariate analysis was performed to identify predictors of MRSA colonization.Results A total o 402 men (447 unique incarcerations) have so far been enrolled (77% AA, 11% Hispanic) with 92% previously in jail (20% in past 6 months). The prevalence of MRSA colonization at intake was 18.6% (83/447), with 39% of those colonized solely in the throat or groin. At 30 days: 10% (9/92) of initially negative men acquired MRSA; 14 admission positives remained colonized while 11 lost colonization. On univariate (Table), predictors of MRSA colonization at entrance to the jail were: methamphetamine use (METH), unstable housing, current skin infection, and care at an outpatient Clinic A that emphasizes comprehensive care to the LGBTQ community. In this cohort, METH use was associated with reporting being a man who has sex with men vs. not (35% vs. 9%, P < 0.001) and was common among men with care at Clinic A (18% vs. 3%, P < 0.001). On multivariate with adjustment for race/ethnicity and HIV status, current skin infection and care at clinic A were associated with MRSA. Preliminarily, sharing personal items was associated with MRSA acquisition at Day30 (OR = 5.6, 95% CI,1.3, 23.3, P = 0.02).ConclusionWe found that a relatively high proportion of individuals enter the jail colonized with MRSA and the jail may amplify rates. Entrance colonization risk factors point to possible community reservoirs. Enrollment is ongoing but results suggest an intervention in jail could impact MRSA rates in the jail and in the surrounding community.Disclosures M. K. Hayden, Sage, Inc: Sage is contributing product to healthcare facilities participating in a regional collaborative on which I am a co-investigator. Neither I nor my hospital receive product., Sage is contributing product to healthcare facilities participating in a regional collaborative on which I am a co-investigator. Neither I nor my hospital receive product.; Clorox, Inc.: I have received funding from Clorox for an investigator-initiated clinical trial., Research support; CDC: Grant Investigator, Research grant

A Snapshot on MRSA Epidemiology in a Neonatal Intensive Care Unit Network, Palermo, Italy.

Objectives: We performed a 1-year prospective surveillance study on MRSA colonization within the five NICUs of the metropolitan area of Palermo, Italy. The purpose of the study was to assess epidemiology of MRSA in NICU from a network perspective.Methods: Transfer of patients between NICUs during 2014 was traced based on the annual hospital discharge records. In the period February 2014–January 2015, in the NICU B, at the University teaching hospital, nasal swabs from all infants were collected weekly, whereas in the other four NICUs (A, C, D, E) at 4 week-intervals of time. MRSA isolates were submitted to antibiotic susceptibility testing, SCCmec typing, PCR to detect lukS-PV and lukF-PV (lukS/F-PV) genes and the gene encoding the toxic shock syndrome toxin (TSST-1), multilocus variable number tandem repeat fingerprinting (MLVF), and multilocus sequence typing (MLST).Results: In the period under study, 587 nasal swabs were obtained from NICU B, whereas 218, 180, 157, and 95 from NICUs A, C, D, and E, respectively. Two groups of NICUs at high prevalence and low prevalence of MRSA colonization were recognized. Overall, 113 isolates of MRSA were identified from 102 infants. Six MLVF types (A–F) were detected, with type C being subdivided into five subtypes. Five sequence types (STs) were found with ST22-IVa being the most frequent type in all NICUs. All the MRSA molecular subtypes, except for ST1-IVa, were identified in NICU B.Conclusions: Our findings support the need to approach surveillance and infection control in NICU in a network perspective, prioritizing referral healthcare facilities.

Methicillin Resistant Staphylococcus aureus among HIV Infected Pediatric Patients in Northwest Ethiopia: Carriage Rates and Antibiotic Co-Resistance Profiles.

BackgroundMRSA infections are becoming more prevalent throughout the HIV community. MRSA infections are a challenge to both physicians and patients due to limited choice of therapeutic options and increased cost of care.ObjectivesThis study was aimed to determine the prevalence of colonization and co-resistance patterns of MRSA species among HIV positive pediatric patients in the Amhara National Regional State, Northwest Ethiopia.MethodsCulture swabs were collected from the anterior nares, the skin and the perineum of 400 participants. In vitro antimicrobial susceptibility testing was done on Muller Hinton Agar by the Kirby-Bauer disk diffusion method, using 30 μg cefoxitin (OXOID, ENGLAND) according to the recommendations of the Clinical and Laboratory Standards Institute. Methicillin sensitivity/resistance was tested using cefoxitin. Data was analyzed by descriptive statistics and logistic regression model using Epi Info 7.Results S. aureus was detected in 206 participants (51.5%). The prevalence of MRSA colonization in this study was 16.8%. Colonization by S. aureus was associated with male gender (OR = 0.5869; 95% CI: 0.3812–0.9036; p-value = 0.0155), history of antibiotic use over the previous 3 months (OR = 2.3126; 95% CI: 1.0707–4.9948; p-value = 0.0329) and having CD4 T-cell counts of more than 350 x 106 cells / L (OR = 0.5739; 95% CI = 0.3343–0.9851; p-value = 0.0440). Colonization by MRSA was not associated with any one of the variables. Concomitant resistance of the MRSA to clindamycin, chloramphenicol, co-trimoxazole, ceftriaxone, erythromycin and tetracycline was 7.6%, 6%, 5.25%, 20.9%, 23.9% and 72.1%, respectively.ConclusionHigh rates of colonization by pathogenic MRSA strains is observed among HIV positive pediatric patients in the Amhara National Regional state.

Prevalence of methicillin-resistant Staphylococcus aureus colonization in HIV-infected patients in Barcelona, Spain: a cross-sectional study

BackgroundColonization by community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) has been found to be markedly more common in HIV-infected individuals in the USA. Studies evaluating the prevalence MRSA colonization in HIV-infected populations in Europe are scarce. The aim of this study was to investigate the prevalence of MRSA colonization in a cohort of HIV-infected patients in Barcelona, Spain.MethodsNasal and pharyngeal S. aureus carriage was assessed in a random sample of 190 patients from an outpatient HIV clinic. Nasal and pharyngeal swab specimens were obtained for staphylococcal culture from 190 and 110 patients respectively. All MRSA isolates were screened for Panton-Valentine leukocidin (PVL) genes by PCR. Molecular characterization of MRSA isolates was performed by multilocus sequence typing. Data related to HIV infection, healthcare exposure, and previously described risk factors for MRSA were collected from medical records and a questionnaire administered to each patient.ResultsThe patients’ characteristics were as follows: male, 83 %; median (IQR) age, 45 (39–49) years; intravenous drug users, 39 %; men who have sex with men, 32 %; heterosexual, 26 %; CD4 count, 528/μL (IQR 351–740); on antiretroviral therapy, 96 %; and undetectable plasma viral load, 80 %. Sixty-five patients (34 %) were colonized by S. aureus. MRSA colonization was found in 1 % and 2 % of nasal and pharyngeal samples respectively. No PVL positive MRSA strains were detected and all the MRSA isolates belonged to typical hospital-acquired clones.ConclusionsOur data suggest that CA-MRSA colonization is not currently a problem in HIV-infected individuals in our area.

Methicillin-resistant staphylococcus aureus (MRSA) colonization among Intensive Care Unit (ICU) patients and health care workers at Muhimbili national hospital, Dar Es Salaam, Tanzania, 2012.

IntroductionMethicillin-resistant Staphylococcus aureus (MRSA) has been recognized as important nosocomial pathogens worldwide. S aureus may induce clinically manifested diseases, or the host may remain completely asymptomatic.MethodsA cross-sectional hospital-based study was conducted from October 2012 to March 2013 in two ICUs at MNH. Admitted patients and health care workers were enrolled in the study. Interviewer administered questionnaires; patient history forms, observation charts and case report forms were used to collect data. Swabs (nostrils, axillary or wounds) were collected. MRSA were screened and confirmed using cefoxitin, oxacillin discs and oxacillin screen agar. Antibiotic susceptibility was performed using Kirby-Bauer disk diffusion method. The risk factors for MRSA were determined using the logistic regression analysis and a p - value of <0.05 was considered as statistically significant.ResultsOf the 169 patients and 47 health workers who were recruited, the mean age was 43.4 years ± SD 15.3 and 37.7 years ± (SD) 11.44 respectively. Among the patients male contributed 108 (63.9%) while in health worker majority 39(83%) were females. The prevalence of MRSA colonization among patients and health care workers was 11.83% and 2.1% respectively. All (21) MRSA isolates were highly resistant to penicillin and erythromycin, and 17 (85.7%) were highly sensitive to vancomycin. Being male (AOR 6.74, 95% CI 1.31-34.76), history of sickness in past year (AOR 4.89, 95% CI 1.82- 13.12), being sick for more 3 times (AOR 8.91, 95% CI 2.32-34.20), being diabetic (AOR 4.87, 95% CI 1.55-15.36) and illicit drug use (AOR 10.18, 95%CI 1.36-76.52) were found to be independently associated with MRSA colonization.ConclusionA study identified a high prevalence of MRSA colonization among patients admitted in the ICU. MRSA isolates were highly resistant to penicillin and erythromycin. History of illegal drug use was highly associated with MRSA colonization.

The Prevalence of Methicillin-Resistant Staphylococcus aureus Colonization in Patients with Complicated Skin and Skin Structure Infections after Treatment with Linezolid or Vancomycin

Background: Complicated skin and skin structure infections (cSSSIs) due to Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), are associated with significant morbidity. Re-ducing MRSA carriage has been a focus of infection control interventions. The prevalence of MRSA colonization after successful treatment of a MRSA cSSSI is unknown. Methods: Secondary analysis of a randomized controlled trial comparing linezolid and vancomycin for the treatment of MRSA cSSSI. Adult patients that had a colonization culture, confirmed MRSA cSSSI, received at least one dose of study treatment, and had an outcome recorded at end of study. Patient, clinical characteristics and prevalence of colonization were compared by treatment regimens. A multivariate regression model identified predictors of MRSA colonization at EOS. Results: There were 456 patients evaluated. The prevalence of MRSA colonization was higher for vancomycin treated patients compared to linezolid treated patients at end of treatment (EOT) (28% vs. 5%, p < 0.001) and EOS (34% vs. 22%, p < 0.01). Independent predictors of colonization at EOS after treatment for a MRSA cSSSI included diagnosis, primarily driven by abscess, black race, treatment with vancomycin, MRSA mixed infection and male gender. Conclusion: Patients treated with linezolid for a cSSSI had less MRSA colonization at EOT and EOS compared to those treated with vancomycin. Multiple independent predictors of MRSA colonization were identified. Additional studies evaluating the relationship of MRSA colonization after treatment of cSSSI are needed.

Prevalence and risk factors forStaphylococcus aureuscolonization in individuals entering maximum-security prisons

To assess the prevalence and risk factors for colonization with Staphylococcus aureus in inmates entering two maximum-security prisons in New York State, USA, inmates (N=830) were interviewed and anterior nares and oropharyngeal samples collected. Isolates were characterized using spa typing. Overall, 50·5% of women and 58·3% of men were colonized with S. aureus and 10·6% of women and 5·9% of men were colonized with MRSA at either or both body sites. Of MSSA isolates, the major subtypes were spa type 008 and 002. Overall, risk factors for S. aureus colonization varied by gender and were only found in women and included younger age, fair/poor self-reported general health, and longer length of prior incarceration. Prevalence of MRSA colonization was 8·2%, nearly 10 times greater than in the general population. Control of epidemic S. aureus in prisons should consider the constant introduction of strains by new inmates.

Low prevalence of meticillin-resistant Staphylococcus aureus carriage at hospital admission: implications for risk-factor-based vs universal screening

There is debate over the optimal policy for detecting meticillin-resistant Staphylococcus aureus (MRSA) colonization at hospital admission. The emergence of community-associated (CA)-MRSA may compromise targeted screening strategies based on risk factors for healthcare-associated (HA)-MRSA. To determine the prevalence of MRSA colonization at admission, and the genotype and molecular epidemiology of the strains involved. A 12-month observational study was performed at a 1200-bed London tertiary referral hospital from 1 April 2008 to 1 March 2009. All available MRSA isolates were genotyped by spa and staphylococcal cassette chromosome mec (SCCmec) typing. The overall MRSA colonization rate was 2.0% of 28,892 admissions (range 6.6% in critical care to 0.8% in obstetrics/gynaecology/neonatology). The overall frequency of previously unknown carriage of MRSA on admission was 1.4%. Most colonizing strains were epidemic HA-MRSA-15 and -16. However, heterogeneous CA strains accounted for 18% of recovered isolates, including 37.5% of MRSA from accident and emergency and 23.1% of MRSA from surgery. The CA-MRSA strain types had significantly different epidemiological associations from the HA-MRSA strains, so risk factors used for the identification of HA-MRSA may not detect CA-MRSA reliably. The low rate of HA-MRSA in the UK increases the relative proportion due to CA-MRSA, for which conventional risk-factor-based screening strategies may be less effective. Cost-benefit analyses of universal MRSA admission screening will need to take account of this new epidemiology.

Prevention of methicillin-resistant Staphylococcus aureus infections in spinal cord injury units

Methicillin-resistant Staphylococcus aureus (MRSA) health care-associated infections (HAIs) are a concern in the 22 acute care Veterans Affairs (VA) spinal cord injury units where patients with unique rehabilitation and medical needs and a high risk of infection are treated. A bundle was implemented in VA spinal cord injury units consisting of nasal surveillance for MRSA on admission/in-hospital transfer/discharge, contact precautions for patients colonized or infected with MRSA, an emphasis on hand hygiene, and an institutional culture change where infection control became everyone's responsibility. From October 2007, through June 2011, there were 51,627 admissions/transfers/discharges and 816,254 patient-days of care in VA spinal cord injury units. The percentage of patients screened increased to >95.0%. The mean admission MRSA prevalence was 38.6% ± 19.1%. Monthly HAI rates declined 81% from 1.217 per 1,000 patient-days to 0.237 per 1,000 patient-days (P < .001). Bloodstream infections declined by 100% (P = .002), skin and soft-tissue infections by 60% (P = .007), and urinary tract infections by 33% (P = .07). Universal surveillance, contact precautions, hand hygiene, and an institutional culture change was associated with significant declines in MRSA HAIs in a setting with a high prevalence of MRSA colonization and a high risk for infection.

Distribution of Equine Encephalosis Virus in Israel

typing. During the study period there were 2235 admissions (1705 different horses), with 2783 MRSA surveillance samples obtained. Samples were collected from 1239/1277 (97%) of horses that were hospitalized for a duration of at least one day; 728 horses (59%) were screened according to protocol and 511 (41%) were screened, but less frequently than protocol. MRSA was isolated from 80 samples during 50 visits by 40 horses (first positive visits: CA–19; CO-HA– 3; HA–17; IN–1; range 0-7 per month). Overall, 3.0% of horses were positive (monthly range 0-8.6%). The prevalence at admission (CA and CO-HA combined) was 1.7% (monthly range 0-7.1%). Three horses had MRSA infections at admission and all were also colonized. No HA clinical MRSA infections were identified. Sixteen (89%) isolates were spa type t064, an ST8 strain commonly found in horses. spa types t002 and t1779 were also identified. Results for first-time positive animals were available for only 7 (18%) prior to discharge. However 11 (28%) colonized horses were later re-admitted, and 7 were still colonized. Within 6 months of the first positive result, 5 owners of MRSA-positive horses brought 14 additional horses to the OVC (range 1-4). Three horses from one of these owners were also colonized. Compliance with MRSA surveillance was good. The prevalence of MRSA colonization varied throughout the study period; however, the 1.7% admission prevalence is similar to previous reports from this facility. The time required for culture hampers the effectiveness of screening as most horses were discharged by the time results were known. However, screening can identify subsequent high risk cases (e.g. previously positive horse, horse from a farm with a colonized horse) and enable the use of enhanced infection control practices while awaiting test results. Screening also allows for detection of changes in MRSA risk posed by the referral population and early identification of within hospital transmission. Ultimately, rapid testing is required to optimize MRSA screening in horses. At defined periods, MRSA colonization was relatively common among equine patients. Screening can be an effective tool to identify high risk cases and reduce transmission, especially if risk analysis incorporates positive results from previous visits and other horses on the farm.

Prevalence, risk factors, and molecular epidemiology of methicillin-resistant Staphylococcus aureus nasal and axillary colonization among psychiatric patients on admission to an academic medical center

Infection control data from psychiatric units and clinics are limited. This time series study was designed to determine the prevalence and risk factors for methicillin-resistant Staphylococcus aureus (MRSA) colonization and/or infection among 500 men and women on admission to psychiatric units at The Johns Hopkins Hospital. Discharge surveillance was conducted to measure incidence. Molecular characterization was performed. Five hundred subjects (52% male) were enrolled. The prevalence of MRSA colonization was 5.2% (26 of 498). Seven of 29 patients (24.1%) admitted with a skin and soft tissue infection (SSTI) was MRSA-positive; 4 of these patients had no other positive site, raising the total admission prevalence to 6.0%. A history of abscess (current or within the past 6 months) on admission (odds ratio [OR], 6.06; 95% confidence interval [CI], 2.40-15.31; P < .001), HIV infection (OR, 4.03; 95% CI, 1.52-10.71; P = .005), previous isolation (OR, 5.03; 95% CI, 1.76-14.35; P = .003), and unknown history of isolation (OR, 4.10; 95% CI, 1.41-11.98; P = .01) were associated with increased odds of MRSA colonization. Seven (2.6%) new MRSA colonizations were identified at discharge. Molecular analysis identified USA300 clonal MRSA isolates. The prevalence of MRSA colonization in this study population was greater than reported in the general population. Further studies are needed to identify transmission dynamics in this environment.

Prevalence of and risk factors for MRSA colonization in HIV-positive outpatients in Singapore

BackgroundWhilst there have been studies on the risks and outcomes of MRSA colonization and infections in HIV-positive patients, local data is limited on the risk factors for MRSA colonization among these patients. We undertook this study in a tertiary HIV care centre to document the risk factors for colonization and to determine the prevalence of MRSA colonization among HIV-positive outpatients in Singapore.MethodsThis was a cross-sectional study in which factors associated with MRSA positivity among patients with HIV infection were evaluated. A set of standardized questionnaire and data collection forms were available to interview all recruited patients. Following the interview, trained nurses collected swabs from the anterior nares/axilla/groin (NAG), throat and peri-anal regions. Information on demographics, clinical history, laboratory results and hospitalization history were retrieved from medical records.ResultsMRSA was detected in swab cultures from at least 1 site in 15 patients (5.1%). Inclusion of throat and/or peri-anal swabs increased the sensitivity of NAG screening by 20%. Predictors for MRSA colonization among HIV-positive patients were age, history of pneumonia, lymphoma, presence of a percutaneous device within the past 12 months, history of household members hospitalized more than two times within the past 12 months, and a most recent CD4 count less than 200.ConclusionsThis study highlights that a proportion of MRSA carriers would have been undetected without multiple-site screening cultures. This study could shed insight into identifying patients at risk of MRSA colonization upon hospital visit and this may suggest that a risk factor-based approach for MRSA surveillance focusing on high risk populations could be considered.

Prevalence and risk factors for methicillin-resistant Staphylococcus aureus colonization in a diabetic outpatient population: A prospective cohort study

Diabetes mellitus is a risk factor for methicillin-resistant Staphylococcus aureus (MRSA) colonization and infection. We attempted to determine the prevalence and risk factors for MRSA colonization in a population of outpatients with diabetes. This prospective cohort study enrolled patients with diabetes. Anterior nares cultures were obtained from patients with diabetes admitted to outpatient endocrinology and metabolism clinics, and risk factors for MRSA colonization were analyzed. Out of the 304 patients evaluated, 127 (41.9%) were colonized with S aureus and 30 (9.9%) were colonized with MRSA. Overall, 23.6% of all S aureus isolates were MRSA. In multivariate analysis, factors independently associated with an increased risk of MRSA colonization included the presence of connective tissue disease (odds ratio, 7.075; 95% confidence interval, 2.157-23.209; P = .001) and insulin therapy (odds ratio, 3.910; 95% confidence interval, 1.652-9.251; P = .002). The prevalence of MRSA colonization in our sample of diabetic outpatients was 9.9%. Independent risk factors for MRSA colonization were the presence of connective tissue disease and insulin use. A better understanding of the epidemiology and risk factors for nasal MRSA colonization in the persons with diabetes may have significant implications for the treatment and prevention of MRSA infections.