Aerial dispersal of meticillin-resistant Staphylococcus aureus in hospital rooms by infected or colonised patients.

The aim of this study was to assess to what extent patients with meticillin-resistant Staphylococcus aureus (MRSA) at respiratory sites shed viable MRSA into the air of hospital rooms. We also evaluated whether the distance from the patient could influence the level of contamination. Air sampling was performed directly onto MRSA-selective agar in 24 hospital rooms containing patients with MRSA colonization or infection of the respiratory tract. Samplings were performed in duplicate at 0.5, 1 and 2-3 m from the patients' heads. Clinical and environmental isolates were compared using antimicrobial resistance patterns and pulsed-field gel electrophoresis. MRSA strains were isolated from 21 out of 24 rooms, in quantities varying from between 1 and 78 cfu/m3. In each of the 21 rooms, at least one of the environmental isolates was identical to a clinical isolate from the patient in that room. There was no significant difference in MRSA counts between the distance from the patient's head and the sampler. This study demonstrates that most patients with MRSA infection or colonisation of the respiratory tract shed viable MRSA into the air of their room. The results emphasise the need to study MRSA in air in more detail in order to improve infection control recommendations.

Nosocomial pertussis in healthcare workers from a pediatric emergency unit in France.

OBJECTIVE: After pertussis was diagnosed in July 1997 in a 55-year-old nurse (case) from a pediatric emergency unit who had a respiratory illness and paroxysmal cough for 5 weeks, an epidemiological investigation was initiated to determine if other healthcare workers (HCWs) from the same unit also had pertussis. DESIGN: Interviews were conducted to assess symptoms occurring in the previous months. Two sera were collected 2 to 3 months apart for 59 of 61 HCWs of the unit. The IgG response to pertussis toxin was determined using Western blot assay. SETTING: Pediatric emergency unit (61 HCWs) of a 2,500-bed university hospital. RESULTS: There was a total of 10 (5 confirmed and 5 probable) cases of pertussis identified in this outbreak. Nine HCWs (15%) had results suggesting recent or acute pertussis. To avoid transmission to patients and other HCWs, all HCWs with cough were treated for 14 days with erythromycin, and those having acute cough were given a 5-day sick leave. Despite these measures, a new acute pertussis case was identified in a 41-year-old nurse, with a positive culture from nasopharyngeal aspirates. Thus, all HCWs in the unit were prescribed spiramycin for 10 days to prevent any further spread of pertussis. CONCLUSION: Pertussis should be considered a threat to HCWs who are in contact with children. For HCWs, diagnosis of pertussis should be made on a clinical basis, giving greater importance to sensitivity of diagnosis criteria, and on early bacterial identification by culture of the organism or by polymerase chain reaction. RECOMMENDATIONS: In case of pertussis in an HCW, all staff in the unit who have had unprotected and intensive contact with that person should be provided with macrolide treatment to stop any transmission to colleagues and to young patients. Furthermore, the possibility of providing these HCWs with acellular pertussis vaccines warrants further investigation.

Usefulness of pulsed-field gel electrophoresis in assessing nosocomial transmission of pertussis.

During a 2-week period, three infants with a cough lasting at least 8 days with whoops, were admitted to the pediatric unit; Bordetella pertussis was isolated from nasopharyngeal aspirates collected from the three infants. Approximately 1 week later, a nurse working on the same unit developed influenza-like symptoms followed by whooping cough; B pertussis was isolated. Isolates from the nurse and from one of the infants were shown to be indistinguishable by pulsed-field gel electrophoresis. These data demonstrate that B pertussis transmission to healthcare workers is possible and emphasize the need to use respiratory protection devices (Droplet Precautions) for healthcare workers having close contact with infected children.

Surveillance of methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE) in Northern France: a five-year multicentre incidence study.

In order to measure the incidence of methicillin-resistant Staphylococcus aureus (MRSA) and of Enterobacteriaceae producing extended-spectrum beta-lactamase (ESBLE), and to evaluate the impact of the national guidelines for multidrug-resistant bacteria (MDRB) prevention in hospitals of Northern France, a multicentre study was conducted for three months every year starting in 1996, in volunteer hospital laboratories. All clinical specimens positive for MRSA and ESBLE were prospectively surveyed. During the five-year surveillance period, the overall proportion of MRSA was 38.4% in the 28,534 strains of S. aureus, and that of ESBLE was 11.4% in the 6121 strains of Klebsiella pneumoniae and 47.7% in the 2353 strains of Enterobacter aerogenes. The overall incidence rates of clinical specimens positive for MRSA, ESBL-K. pneumoniae and E. aerogenes were 0.84. 0.05 and 0.12/1000 hospital-days (HD), respectively. In the 23 hospitals that participated in the survey every year, the proportion and incidence of ESBLE decreased. Hence, despite recommendations as for isolation precautions, MRSA remains poorly controlled and requires more effective measures.

Efficacy of antibiotic-lock technique with teicoplanin in staphylococcus epidermidis catheter-related sepsis during long-term parenteral nutrition.

BACKGROUND: The antibiotic-lock technique has been suggested to treat catheter-related sepsis in parenteral nutrition and to avoid catheter removal. METHODS: To determine the incidence of catheter-related sepsis, the bacteria involved, and the efficacy of the antibiotic-lock technique with teicoplanin, all patients (n = 263) undergoing parenteral nutrition from January 1997 to December 1999 in one center, with patients at the hospital (n = 209) and at home (54) were retrospectively studied. The antibiotic-lock technique with teicoplanin was systematically used in all suspected infections and maintained in staphylococcus epidermidis (SE) infections. RESULTS: A total of 21 of 263 patients had 34 infections (0.11/patient per year): 12 of 209 hospitalized and 9 of 54 home patients. A total of 10 of 34 infections were due to non-SE, and the catheter was immediately removed. The other 24 of 34 infections were due to SE; in 5 of 24, the catheter was removed after 48 hours of the antibiotic-lock technique because of persistent fever or thrombosis. A total of 5 of 12 patients had 2 or more infections on the same catheter. The antibiotic-lock technique prevented short-term catheter removal in these cases, but a second infection occurred within a median of 50 days. In 4 of 5 cases, a third infection occurred in a mean delay of 90 days so that the catheter was removed. In 3 of 5 patients, bacteria was analyzed with pulsed field gel electrophoresis, which showed that recurrent infections were due to the same strain in all cases. CONCLUSIONS: In this study, the incidence of catheter-related sepsis was low and mostly related to SE. Our results do not support the use of the teicoplanin antibiotic-lock technique in SE infections.

[Efficacy of a multidisciplinary team for preventing hospital-acquired invasive aspergillosis: five years' experience]. / Efficacité des mesures environnementales dans la prévention de l'aspergillose invasive nosocomiale liée aux travaux: bilan de cinq années d'expérience.

Invasive hospital-acquired aspergillosis (IA) is responsible for lethal outbreaks. In 2002, an interdisciplinary team was created in the teaching hospital of Rouen in order to organize the surveillance of construction sites by the implementation of environmental measures of prevention. The aim of our study was to estimate the efficiency of these measures using an indirect indicator, reflecting the incidence of the cases of invasive nosocomial aspergillosis (AI): the consumption of antifungals. From the nominative prescriptions established, we studied the medical files about 210 patients to track down the number of IA cases in intensive care unit (ICUI) and in pediatric hematology-oncology units between 2002 and 2006. The incidence of the cases was put in parallel with the various periods of level 5-risk works during these five years. The relative risk of appearance of the disease was calculated. In pediatric haematology-oncology unit, 35 cases were diagnosed on 99 medical files which have been studied and in ICU 19 cases were classified on 93 studied files. The follow-up of the incidence in both units stake in parallel with the periods of level 5-risk works does not show increase of the number of cases. The calculated relative risk indicates the same result: the level 5-risk works are not a factor facilitating the appearance of invasive aspergillosis cases. This study shows the importance of the environmental measures of prevention during the periods of works within services for risk. The coordination of the actors within an interdisciplinary cell seems thus essential for the prevention of AIN.

Clonal outbreaks of extended-spectrum beta-lactamase-producing strains of Klebsiella pneumoniae demonstrated by antibiotic susceptibility testing, beta-lactamase typing, and multilocus enzyme electrophoresis.

Nineteen extended-spectrum beta-lactamase (ESBla)-producing Klebsiella pneumoniae isolates from Rouen Hospital were investigated for their implication in nosocomial outbreaks: in addition to antibiotic susceptibility testing, the ESBlas were characterized by isoelectric focusing, and the genetic relationships between the strains were analyzed by multilocus enzyme electrophoresis using a combined polyacrylamide electrophoresis-electrophoretic transfer technique. Four isoelectric focusing beta-lactamase patterns and 11 enzyme electrophoretic types (ETs) among the strains tested were described. Three strains isolated in the same neurological unit over a 7-day period exhibited an SHV 3 beta-lactamase (pI 7.0) and were assigned to a common ET. Three of five strains isolated from patients in a rehabilitation center over a 6-week period harbored an SHV 4 beta-lactamase (pI 7.8) and exhibited the same ET. These results differentiate nosocomial transmission from sporadic cases and provide evidence that multilocus enzyme electrophoresis is a potential tool for studying genetic relationships between strains harboring a common ESBla.

Evaluation of the Epsilometer test (E test) for testing the susceptibility of coagulase-negative staphylococci to teicoplanin.

The antimicrobial susceptibilities of 118 clinical isolates of coagulase-negative staphylococci to teicoplanin were determined by disc diffusion and the Epsilometer test (E test) and the results were compared with the MICs determined by the agar dilution method of the National Committee for Clinical Laboratory Standards (NCCLS). There was a poor correlation of r = 0.5 between the zone diameters of inhibition and agar dilution MICs and 10 and four of the 11 isolates for which the MICs were > or = 32 mg/L were misclassified as susceptible by the disc test after applying the interpretative criteria of the NCCLS and the Comité de l'Antibiogramme de la Société Française de Microbiologie (CASFM), respectively. The E test tended to result in MICs that were lower than those determined by agar dilution and only 66% of MIC were within +/- 1 log2 dilution of each other. Only one of 11 resistant strains was detected by the E test and, although there was no false resistance, six resistant strains were misclassified as susceptible after applying the criteria of the NCCLS as were four such isolates when the criteria of the CASFM were employed, probably as a result of using too light an inoculum. Disc diffusion is not a reliable means of determining the susceptibility of coagulase-negative staphylococci but might be replaced by the E-test provided that discrepant results can be resolved by using a denser inoculum.

[Neonatal septicemia due to Pneumococcus resistant to beta-lactam antibiotics]. / Septicémie néonatale à pneumocoque résistant aux bêtalactamines.

BACKGROUND: Neonatal sepsis due to Streptococcus pneumoniae is relatively rare. The increasing risk that this bacterium is resistant to betalactam antibiotics worsens its prognosis. CASE REPORT: A newborn was delivered by cesarean section because of an abnormal fetal heart rate pattern. Despite intubation, respiratory support and correction of acidosis, the baby remained cyanotic and displayed signs of shock. Neutropenia, increased percentage of immature neutrophils, high C-reactive protein levels and an X-ray pattern of pneumonia also indicated an infection. The child was given symptomatic therapy, and amoxicillin, cefotaxime and amikacin. Pneumococci type 9 were isolated from peripheral secretions and from the blood. Deterioration of the respiratory condition required higher doses of amoxicillin and cefotaxime on day 2 pending the results of antibiotic sensitivity testing. This test showed that the strains were resistant to beta-lactam antibiotics. On day 3, the treatment was replaced by a combination of vancomycin, rifampicin, amikacin and cefotaxime. This treatment was pursued for 2 weeks, except for rifampicin which was stopped after 2 days. The follow-up was uneventful. A search for pneumococci in the mother was negative. CONCLUSIONS: Streptococcus pneumoniae should always be considered as a cause of neonatal sepsis. Poor therapeutic control indicates resistance to beta-lactam antibiotics. This patient may be the first reported case of maternal-fetal infection with this resistant strain.

Clonal and temporal patterns of nasopharyngeal penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae stains in children attending a day care center.

The nasopharyngeal carriage of penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae (PSSp and PRSp, respectively) was analyzed in 116 children attending a day care center in Rouen, France, by three observation periods in November, January, and March of the winter of 1993 to 1994. The carriage rate of S. pneumoniae was found to be 47.7, 47.3, and 49.6% at each different observation period, and PRSp accounted for 42.2, 40.3, and 40.6% of pneumococcal isolates, respectively. The 52 isolates recovered in November were distributed in 34 electrophoretic types (ETs) by multilocus enzyme electrophoresis; 15 PRSp isolates, all of serotype 23F, belonged to a clonal complex of five ETs, representing the dominant population of PRSp in November. The temporal pattern of S. pneumoniae carriage was studied in 17 children who were colonized at the three periods by multilocus enzyme analysis of their isolates. The PSSp isolated, exhibiting distinct ETs, were transient only among these day care attendees. In contrast, most of the PRSp isolated in January and March belonged to the clonal complex. Thus, this PRSp population was resident in the day care center throughout the study period.