The epidemiology of methicillin-susceptible and methicillin-resistant Staphylococcus aureus in a neonatal intensive care unit, 2000-2007.

OBJECTIVE: To assess the epidemiology of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) infections in a neonatal intensive care unit (NICU). STUDY DESIGN: A retrospective chart review was conducted from 2000-2007; demographic and clinical characteristics of infected infants and crude mortality were assessed. RESULTS: During the study period, there were 123 infections caused by MSSA and 49 infections caused by MRSA. Although the types of infections caused by MSSA and MRSA were similar, infants with MRSA infections were younger at clinical presentation than infants with MSSA infections (P=0.03). The overall rate of S. aureus infections was approximately 15-30 per 1000 patient-admissions. The rate of bacteremia and skin and soft tissue infections remained stable over time. Among extremely low birth weight infants (birth weight <1000 g), 4.8 and 1.8% developed an infection caused by MSSA or MRSA, respectively. Infections occurred in a bimodal distribution of birth weight; 53% of infections occurred in extremely low birth weight infants and 27% occurred among term infants birth weight >or=2500 g, many of whom underwent surgical procedures. CONCLUSIONS: MSSA and MRSA remain significant pathogens in the NICU, particularly for extremely premature infants and term infants undergoing surgery. Further work should investigate infection control strategies that effectively target the highest risk groups and determine if vertical transmission of MRSA is responsible for the younger age at presentation of infection.

Rapid detection of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in wound specimens and blood cultures: multicenter preclinical evaluation of the Cepheid Xpert MRSA/SA skin and soft tissue and blood culture assays.

A multicenter preclinical evaluation was conducted to evaluate the performance of two Cepheid Xpert assays for detection of methicillin-resistant Staphylococcus aureus (MRSA) and S. aureus. Sensitivity was 97.1% and 98.3% for MRSA in wound and blood culture specimens, respectively. Sensitivity was 100% for S. aureus from both specimen types.

Análisis de factores de riesgo de gravedad de la coqueluche en un hospital pediátrico / Analysis of risk factors for severe pertussis in a pediatric hospital

A pesar de la implementación de la vacuna antipertussis en el Calendario Nacional continúan ocurriendo casos graves de coqueluche en Argentina. Objetivo: Identificar factores de riesgo de gravedad al ingreso hospitalario (definida como requerimientos de internación en Unidad de Cuidados Intensivos o fallecimiento). Métodos: Estudio de casos y controles: 32 casos de coqueluche vs. 89 casos no graves (enero el diciembre de 2004 y 2007). Todos los casos y controles fueron confirmados por PCR en SNF. Análisis estadístico (STATA 8.0). Resultados: 121 pacientes fueron incluidos (edad mediana 2 meses). Se observó contacto con adulto tosedor 35 por ciento vacunación en el 54 por ciento (1 dosis en 71 por ciento, 2 dosis en 21 por ciento, 3 dosis en 6 por ciento, 4 dosis en el 2 por ciento). Quince niños de los 32 que requirieron UCI fallecieron. Los motivos de admisión a UCI fueron falla respiratoria severa en 15 pacientes (47 por ciento) y asociada a falla hemodinámica in 17 p. (53 por ciento). Análisis multivariado la leucocitosis mayor a 50 por 10 3 (OR 4.46 IC 95 por ciento 1.66- 11.99) y la apnea (OR 4IC95 por ciento 1.53 - 10.91), al ingreso hospitalario fueron predictores de mal pronóstico. Conclusiones: Los niños pequeños sin edad suficiente para recibir la vacuna tienen riesgo de presentar formas graves. La leucocitosis y la apnea fueron predictores de mal pronóstico. Los pacientes con riesgo de enfermedad severa grave deben tener acceso a centros de alta complejidad. Se debe mantener alta sospecha disgnóstica y cobertura de vacunación adecuada.

Drug-resistant tuberculosis in Castilla-León, Spain, 1996-2000.

SETTING: During 1996-2000, a regional anti-tuberculosis drug resistance survey was conducted in Castilla-León, Spain. OBJECTIVE: To determine the incidence of drug-resistant tuberculosis (TB) in newly treated human immunodeficiency virus (HIV) negative and HIV-positive TB patients. DESIGN: Nine hundred and eighty-five Mycobacterium tuberculosis strains isolated from HIV-negative (926) and HIV-positive (59) patients were studied (one strain per patient). Univariate and multivariate analyses were used to determine the prevalence of drug resistance in high-risk groups. RESULTS: Thirty-eight isolates (3.8%) showed resistance to one of the following drugs: streptomycin (S), isoniazid (H), rifampicin (R) or ethambutol (E). Of these, 36 (3.9%) were from HIV-negative and 2 (3.4%) from HIV-positive patients. The rate of drug resistance among HIV-negative patients was 1.2%, 2.0%, 0.3% and 0.8%, respectively, for S, H, R and E, and for HIV-positive patients it was 3.4%, 0%, 0% and 1.7%. Among the HIV-negative patients, monoresistance was observed in 32 (3.4%) strains and resistance to both H and R (multi-drug resistance) was detected in one. CONCLUSION: The incidence of primary drug resistance in the surveyed area was low and increased resistance was not observed in the HIV-positive group (P = 0.99). Routine surveillance of drug resistance is recommended by the TB control programme in representative patient populations to optimise treatment regimens.

A comparison of the bacteria found on the hands of 'homemakers' and neonatal intensive care unit nurses.

This prevalence study was conducted to compare the counts, types and antimicrobial resistance profiles of bacterial flora on the hands of individuals in the community to that of nurses at a nearby university teaching hospital, with an intense hand hygiene regimen. Hand cultures were obtained from 204 individuals during a home visit and 119 nurses in two neonatal intensive care units (NICUs). The mean total log counts of organisms were 5.73 and 5.24 for the homemakers [defined as the person (usually the mother) who is the primary person responsible for arranging childcare, cooking, cleaning etc] and nurse hands, respectively (P<0.0001). Significantly more homemakers had Acinetobacter lwoffii, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, P. fluorescens/putida, and Staphylococcus aureus on their hands compared with the nurses (all P<0.05). However, significantly more nurses had Enterococcus faecalis, S. epidermidis, and S. warneri on their hands (P<0.05). Of note, the hands of nurses harboured significantly more S. epidermidis strains resistant to amoxicillin/clavulanate, cefazolin, clindamycin, erythromycin, and oxacillin and S. warneri resistant to amoxicillin/clavulanate, cefazolin, clindamycin, and oxacillin (P<0.05). Surprisingly, significantly more trimethoprim/sulfamethoxazole-resistant S. epidermidis and ciprofloxacin-resistant S. warneri was recovered from the hands of homemakers (P<0.05). This study demonstrates differences in prevalence, bacterial composition and antimicrobial resistance of hand flora of hospital personnel compared with homemakers. Moreover, the hands of homemakers may serve as community reservoirs for antimicrobial resistant strains of clinical importance.

Bacteriological conversion in twenty urinary tuberculosis patients treated with ofloxacin, rifampin and isoniazid: a 10-year follow-up study.

Twenty patients with urinary tuberculosis were treated with ofloxacin (200 mg/day, 6 months), rifampin (600 mg/day, 3 months) and isoniazid (300 mg/day, 3 months) between 1989 and 1990. All patients were new cases, diagnosed by observation and/or isolation of Mycobacterium tuberculosis in one of the three morning urine samples. Bacteriological culture conversion (negativization) was assessed as a clinical guide of efficacy, comparing it, as the only parameter, against a control group (150 patients) with urinary tuberculosis who received conventional therapy. Bacteriological follow-up studies were performed in both groups monthly for 6 months, then again 6 months later and then every year for 10 years after completion of treatment. In the 20 patients, the initial culture was positive with over 100 colonies per culture (>50%); the smear was positive in 45% of the patients (most were 2+). All strains were susceptible to rifampin, isoniazid and ofloxacin. Two patients discontinued treatment. Beginning with the first month of treatment, the bacteriological conversion was 100%, 89.5% and 100% in the remaining controls. In the control group, which received conventional treatment, the conversion was: 90%, 87%, 93% and 100% in the remaining controls. Treatment with ofloxacin resulted in a bacteriological conversion similar to that following conventional treatment ( p>0.05, Fisher's exact test). After 10 years of patient follow-up, we conclude that ofloxacin, in combination with rifampin and isoniazid (both for 3 months only is effective against M. tuberculosis, providing satisfactory bacteriological and clinical efficacy.

Plesiomonas shigelloides sepsis and splenic abscess in an adolescent with sickle-cell disease.

Plesiomonas shigelloides is a rare cause of self-limiting gastroenteritis. We report a case of extraintestinal P. shigelloides infection in an adolescent with sickle-cell disease who presented with bacteremia complicated by a splenic abscess. Despite the high mortality rate reported in extraintestinal P. shigelloides infection, the patient survived after drainage of the abscess and treatment with antibiotics.

Relationship between skin microbial counts and surgical site infection after neurosurgery.

A prospective study was performed to describe the density of bacterial counts on the skin of neurosurgical patients and examine the association between total colony-forming unit (cfu) counts of skin flora at the operative site and surgical site infection (SSI). Two skin cultures were obtained, immediately before and after skin preparation, from the operative sites of 609 neurosurgical patients. SSI surveillance that used Centers for Disease Control/National Nosocomial Infection Surveillance definitions was performed. Predictors for high bacterial counts and SSI among craniotomies were analyzed by means of logistic regression. Neither pre- nor postpreparation counts were associated with SSI. Other SSI risk factors were obesity (relative risk [RR], 2.5), duration of surgery (RR, 1.3 for every additional 30 minutes) and age (RR, 0.7 for each additional 10 years). Duration of skin preparation was not correlated with postpreparation cfu counts. We were unable to detect an association between preoperative bacterial skin counts and SSI.

Vancomycin-resistant Enterococcus faecium meningitis successfully managed with linezolid: case report and review of the literature.

Enterococci cause serious illness in immunocompromised patients and severely ill, hospitalized patients. Resistance to vancomycin has increased in frequency during the past few years. Limited therapeutic options are available for vancomycin-resistant enterococcal infections and the optimum therapy has not been established. We report a case of nosocomial vancomycin-resistant Enterococcus faecium meningitis in the setting of hyperinfection with Strongyloides stercoralis that was successfully treated with linezolid. We also review the previously reported cases of vancomycin-resistant E. faecium meningitis.

Persistence of immunity to varicella-zoster virus after vaccination of healthcare workers.

OBJECTIVE: Varicella-zoster virus (VZV) vaccine is recommended to protect susceptible healthcare workers (HCWs) from serious disease and to prevent nosocomial spread of VZV. We evaluated clinical outcomes and serological responses in HCWs after immunization with live attenuated VZV vaccine. DESIGN: Vaccinees were immunized from 1979 to 1998 during VZV vaccine trials, as well as after licensure, and followed prospectively for 1 month to 20.6 (mean 4.6) years after vaccination. Sera were tested by fluorescent antibody to membrane antigen (FAMA), latex agglutination (LA), and enzyme-linked immunoassay (EIA) to detect VZV-specific antibodies. STUDY PARTICIPANTS: The median age of the 120 HCWs was 26 years; 51 (42%) were males. INTERVENTIONS: Ninety eight (82%) of these study subjects received vaccine prepared by Merck and 22 (18%) by SmithKline Beecham; 25, 81, and 14 vaccinees received one dose, two doses, and three doses, respectively. RESULTS: The crude attack rate was 10%; 12 of 120 HCWs developed chickenpox 6 months to 8.4 years after vaccination. The attack rates following household and hospital exposures were 18% (4/22) and 8% (6/72), respectively. All resulting illness was mild to moderate (mean 40 vesicles). Seroconversion after vaccination was documented by FAMA in 96% of HCWs, although 31% lost detectable antibodies. Compared with FAMA, LA and EIA were 82% and 74% sensitive and 94% and 89% specific, respectively. CONCLUSIONS: The VZV vaccine effectively protected HCWs from varicella, particularly from serious disease. Currently available serological tests are not optimal, and improved assays are needed.

Nosocomial rotavirus in a pediatric hospital.

We describe a nosocomial rotavirus outbreak among pediatric cardiology patients and the impact of a prospective, laboratory-based surveillance program for rotavirus in our university-affiliated, quartenary-care pediatric hospital in New York City. Improved compliance with infection control and case-finding among patients and healthcare workers halted the outbreak.

Assessment of two hand hygiene regimens for intensive care unit personnel.

OBJECTIVE: To compare skin condition and skin microbiology among intensive care unit personnel using one of two randomly assigned hand hygiene regimens: a 2% chlorhexidine gluconate (CHG)-containing traditional antiseptic wash and a waterless handrub containing 61% ethanol with emollients (ALC). DESIGN: Prospective, randomized clinical trial. SETTING: Two critical care units (medical and surgical) in a large, metropolitan academic health center in Manhattan. SUBJECTS: Fifty staff members (physicians, nurses, housekeepers, respiratory therapists) working full time in the intensive care unit. INTERVENTIONS: One of two hand hygiene regimens randomly assigned for four consecutive weeks. MEASUREMENTS AND MAIN RESULTS: The two outcomes were skin condition (measured by two tools: Hand Skin Assessment form and Visual Skin Scaling form) and skin microbiology. Samples were obtained at baseline, on day 1, and at the end of wks 2 and 4. Participants in the ALC group had significant improvements in the Hand Skin Assessment scores at wk 4 (p = 0.04) and in Visual Skin Scaling scores at wks 3 (p = 0.01) and 4 (p = 0.0005). There were no significant differences in numbers of colony-forming units between participants in the CHG or ALC group at any time period. The ALC regimen required significantly less time than the CHG regimen (mean: 12.7 secs and 21.1 secs, respectively; p = 0.000) and resulted in a 50% reduction in material costs. CONCLUSIONS: Changes in hand hygiene practices in acute care settings from the traditional antiseptic wash to use of plain, mild soap and an alcohol-based product should be considered. Further research is needed to examine the association between use of antiseptic products for hand hygiene of staff and reductions in nosocomial infection rates among patients.

Comparison of different regimens for surgical hand preparation.

Twenty surgical staff members participated in a clinical trial to compare the microbiology and skin condition of hands when using a traditional surgical scrub (TSS) with a detergent-based antiseptic containing 4% chlorhexidine gluconate (CHG) and a short application without scrub of a waterless hand preparation (HP) containing 61% ethyl alcohol, 1% CHG, and emollients. The HP was associated with less skin damage (P = .002) and lower microbial counts postscrub at days five (P = .002) and 19 (P = .02). The HP protocol had shorter contact time (HP mean [M] = 80.7 seconds; TSS M = 144.9 seconds; P < .0001), and more subjects preferred the HP regimen (P = .001). The HP performed better than the TSS, was less costly, and should be evaluated in larger trials and considered for widespread implementation.

An outbreak of Legionella micdadei pneumonia in transplant patients: evaluation, molecular epidemiology, and control.

PURPOSE: To describe a nosocomial outbreak of Legionella micdadei pneumonia in transplant patients and to characterize the source of the outbreak and the control measures utilized. SUBJECTS AND METHODS: We performed retrospective Legionella micdadei serologic testing to enhance case finding in transplant patients with pneumonia that lacked a documented microbial etiology, as well as prospective environmental surveillance of water sites and testing for Legionella in clinical specimens. RESULTS: During a 3-month period, 12 cases of Legionella micdadei pneumonia were identified either by culture or serologic testing among 38 renal and cardiac transplant patients. Legionella micdadei isolates from hot water sources were found by pulsed-field gel electrophoresis to have a DNA banding pattern that was identical to the isolates from the first 3 culture-positive cases and from 2 cases that occurred 16 months later. CONCLUSIONS: Hospitals caring for organ transplant recipients and other immunosuppressed patients must be aware of the possibility of environmental sources of outbreaks of Legionella infection. A first-line screen with the Legionella urine antigen test will identify Legionella pneumophila serogroup 1. However, specific cultures in outbreak situations should be considered to identify other Legionella pneumophila serotypes and the nonpneumophila Legionella species.

Endemic Pseudomonas aeruginosa infection in a neonatal intensive care unit.

BACKGROUND: Nosocomial infections due to Pseudomonas aeruginosa have been well described, but the environmental reservoir of the organism varies. We conducted an epidemiologic and molecular investigation of endemic P. aeruginosa infection among infants in a neonatal intensive care unit that was associated with carriage of the organisms on the hands of health care workers. METHODS: In August 1998, colonization or infection with P. aeruginosa was identified in six infants. Surveillance cultures for P. aeruginosa were obtained from the other 27 infants in the unit, and possible environmental reservoirs were also assessed. The hands of health care workers were inspected and cultured, and risk factors for P. aeruginosa colonization were evaluated. Isolates were analyzed for clonality by pulsed-field gel electrophoresis. RESULTS: Surveillance cultures showed that three additional infants were colonized with P. aeruginosa. Cultures of environmental specimens were negative, but cultures of the hands of 10 of 165 health care workers (6 percent) were positive for P. aeruginosa. Increasing age (P=0.05) and a history of the use of artificial fingernails or nail wraps (P=0.03) were both risk factors for colonization of the hands. From January 1997 to August 1998, 49 infants were infected or colonized with P. aeruginosa. Pulsed-field gel electrophoresis demonstrated that 17 of these infants and 1 health care worker who had onychomycosis had the same clone. Infants who were exposed to this health care worker in August 1998 were at greater risk of having this clone than infants who were not exposed to this health care worker (odds ratio, 41.2; 95 percent confidence interval, 1.8 to 940.0; P=0.006). CONCLUSIONS: An increased rate of infection and colonization with P. aeruginosa among infants in neonatal intensive care units should be investigated by assessing potential reservoirs, including environmental sources as well as patients and health care workers.

Differences in skin flora between inpatients and chronically ill outpatients.

BACKGROUND: Changes in skin flora have been reported among hospitalized and critically ill patients, but little is known about whether these changes are associated with hospitalization or with chronic, serious illness. The purpose of this survey was to compare skin flora of chronically ill outpatients and inpatients. METHODS: Aerobic skin flora of forearm and midsternum of 250 patients in an intensive care unit and 251 outpatients was sampled by contact plates. RESULTS: Mean colony-forming units were 160.6, forearm; 229. 4, sternum (P <.000). In logistic regression analysis, patients in the medical intensive care unit were significantly more likely to have high counts on the arm (odds ratio, 2.48; 95% confidence interval: 1.34-4.43; P =.004), and blacks were significantly more likely to have higher counts on the sternum when compared with other ethnic groups (odds ratio, 1.92; confidence interval: 1.18-3.11; P =. 009). No differences were noted between inpatients or outpatients in prevalence of methicillin-sensitive Staphylococcus aureus, but inpatients were more likely to carry methicillin-resistant Staphylococcus aureus (arm, P =.007; sternum, P =.02). Outpatients had a higher prevalence of micrococci and gram-negative bacteria at both skin sites (all P <.01) and yeast at the sternal site (P =.007). CONCLUSIONS: This comparison provides data to differentiate between effects of hospitalization and effects of chronic illness on skin flora.

Nonsusceptible Streptococcus pneumoniae in children with chronic otitis media with effusion and recurrent otitis media undergoing ventilating tube placement.

CONTEXT: Children with chronic otitis media are at risk for nonsusceptible Streptococcus pneumoniae (NSP) infection. If these children undergo ventilating tube placement, there is an opportunity to culture middle ear fluid and the nasopharynx to determine carriage of NSP. OBJECTIVE: To determine the incidence of NSP carriage, NSP antibiotic susceptibility and risk factors for NSP carriage in children with chronic otitis media undergoing tube placement. DESIGN AND SETTING: Prospective cohort study in an academic medical center with recruitment of patients from an otolaryngology private practice and clinic. PATIENTS: Children < 18 years of age undergoing tube placement for chronic otitis media. INTERVENTIONS: Myringotomy and tube placement, with culture of middle ear fluid and nasopharynx. MAIN OUTCOME MEASURES: The incidence of NSP cultured from the middle ears and nasopharynx of recruited subjects with the use of the minimum inhibitory concentration break points for penicillin susceptibility recommended by the National Committee for Clinical Laboratory Standards. RESULTS: S. pneumoniae was identified in at least 1 site from 23 of 300 study subjects (7.6%); of these 23, 12 case subjects (52.2%) harbored NSP. Of the risk factors assessed by preoperative questionnaire, only younger age was associated with NSP colonization (P < 0.0001). Of the six oral cephalosporins studied, cefpodoxime and cefuroxime showed good in vitro activity against S. pneumoniae isolates with intermediate penicillin resistance. CONCLUSIONS: Children with chronic otitis media undergoing tube placement may carry NSP and provide a means of monitoring the incidence of NSP and antibiotic susceptibilities for children with ear infections in their communities. Younger age is a risk factor for NSP carriage in this population.

Assessment of alternative hand hygiene regimens to improve skin health among neonatal intensive care unit nurses.

OBJECTIVE: The frequent handwashing and gloving required in high-risk, high-volume patient care areas such as critical care units damages skin of the hands. The purpose of this exploratory study was to compare 2 hand care regimens (traditional antiseptic wash with chlorhexidine-containing detergent versus mild soap wash with subsequent alcohol-based rinse for degerming as necessary) in a neonatal intensive care unit (NICU). DESIGN: Prospective, quasi-experimental, random assignment. SETTING: One NICU (47 beds) in a New York City children's hospital. SUBJECTS: Sixteen full-time NICU nurses. OUTCOME MEASURES: Microbial flora and skin condition of hands. INTERVENTION: Nurses were randomly assigned to one of the 2 hand care regimens. RESULTS: No significant differences in microbial counts or types of organisms from hands of staff were found, but after 2 weeks nurses in the mild soap and alcohol group had significant improvements in their skin condition (P =.005). CONCLUSIONS: Use of a mild soap for cleaning and an alcohol-based product for degerming may offer an acceptable alternative to the traditional antiseptic handwash and may reduce skin damage to health care professionals' hands.

The role of clinical suspicion in evaluating a new diagnostic test for active tuberculosis: results of a multicenter prospective trial.

CONTEXT: In laboratory trials, nucleic acid amplification tests for the diagnosis of tuberculosis (TB) are more accurate than acid-fast bacilli (AFB) smear microscopy and are faster than culture. The impact of these tests on clinical diagnosis is not known. OBJECTIVE: To assess the performance of a nucleic acid amplification test, the enhanced Mycobacterium tuberculosis Direct (E-MTD) test, against a uniform clinical standard stratified by level of clinical suspicion. DESIGN: Prospective multicenter trial conducted between February and December 1996, documenting the clinical suspicion of TB at enrollment and using final comprehensive diagnosis as the criterion standard. SETTING: Six urban medical centers and 1 public health TB clinic. PATIENTS: A total of 338 patients with symptoms and signs consistent with active pulmonary TB and complete clinical diagnosis were stratified by the clinical investigators to be at low (< or =25%), intermediate (26%-75%), or high (>75%) relative risk of having TB. MAIN OUTCOME MEASURES: Sensitivity, specificity, and positive and negative predictive values of the E-MTD test in clinical suspicion of groups with low (n = 224); intermediate (n = 68); and high (n = 46) clinical suspicion of TB. RESULTS: Based on comprehensive clinical diagnosis, sensitivity of the E-MTD test was 83%, 75%, and 87% for low, intermediate, and high clinical suspicion of TB, respectively, and corresponding specificity was 97%, 100%, and 100% (P = .25). Positive predictive value of the E-MTD test was 59% (low), 100% (intermediate), and 100% (high) compared with 36% (low), 30% (intermediate), and 94% (high) for AFB smear. Corresponding negative predictive values were 99%, 91%, and 55% [corrected] (E-MTD test) vs 96%, 71%, and 37% (AFB smear). CONCLUSIONS: For complex diagnostic problems like TB, clinical risk assessments can provide important information regarding predictive values more likely to be experienced in clinical practice. For this series, a clinical suspicion of TB was helpful in targeting areas of the clinical spectrum in which nucleic acid amplification tests can make an important contribution.