Seroprevalence of SARS-CoV-2 antibodies among healthcare workers in Dutch hospitals after the 2020 first wave: a multicentre cross-sectional study with prospective follow-up.

BACKGROUND: We aimed to estimate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence and describe its determinants and associated symptoms among unvaccinated healthcare workers (HCWs) after the first wave of the pandemic. METHODS: HCWs from 13 Dutch hospitals were screened for antibodies against the spike protein of SARS-CoV-2 in June-July 2020 and after three months. Participants completed a retrospective questionnaire on determinants for occupational and community exposure to SARS-CoV-2 and symptoms suggestive of COVID-19 experienced since January 2020. The seroprevalence was calculated per baseline characteristic and symptom at baseline and after follow-up. Adjusted odds ratios (aOR) for seropositivity were determined using logistic regression. RESULTS: Among 2328 HCWs, 323 (13.9%) were seropositive at enrolment, 49 of whom (15%) reported no previous symptoms suggestive of COVID-19. During follow-up, only 1% of the tested participants seroconverted. Seroprevalence was higher in younger HCWs compared to the mid-age category (aOR 1.53, 95% CI 1.07-2.18). Nurses (aOR 2.21, 95% CI 1.34-3.64) and administrative staff (aOR 1.87, 95% CI 1.02-3.43) had a higher seroprevalence than physicians. The highest seroprevalence was observed in HCWs in the emergency department (ED) (aOR 1.79, 95% CI 1.10-2.91), the lowest in HCWs in the intensive, high, or medium care units (aOR 0.47, 95% CI 0.31-0.71). Chronic respiratory disease, smoking, and having a dog were independently associated with a lower seroprevalence, while HCWs with diabetes mellitus had a higher seroprevalence. In a multivariable model containing all self-reported symptoms since January 2020, altered smell and taste, fever, general malaise/fatigue, and muscle aches were positively associated with developing antibodies, while sore throat and chills were negatively associated. CONCLUSIONS: The SARS-CoV-2 seroprevalence in unvaccinated HCWs of 13 Dutch hospitals was 14% in June-July 2020 and remained stable after three months. A higher seroprevalence was observed in the ED and among nurses, administrative and young staff, and those with diabetes mellitus, while a lower seroprevalence was found in HCWs in intensive, high, or medium care, and those with self-reported lung disease, smokers, and dog owners. A history of altered smell or taste, fever, muscle aches and fatigue were independently associated with the presence of SARS-CoV-2 antibodies in unvaccinated HCWs.

COVID-19 in health-care workers in three hospitals in the south of the Netherlands: a cross-sectional study.

BACKGROUND: 10 days after the first reported case of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in the Netherlands (on Feb 27, 2020), 55 (4%) of 1497 health-care workers in nine hospitals located in the south of the Netherlands had tested positive for SARS-CoV-2 RNA. We aimed to gain insight in possible sources of infection in health-care workers. METHODS: We did a cross-sectional study at three of the nine hospitals located in the south of the Netherlands. We screened health-care workers at the participating hospitals for SARS-CoV-2 infection, based on clinical symptoms (fever or mild respiratory symptoms) in the 10 days before screening. We obtained epidemiological data through structured interviews with health-care workers and combined this information with data from whole-genome sequencing of SARS-CoV-2 in clinical samples taken from health-care workers and patients. We did an in-depth analysis of sources and modes of transmission of SARS-CoV-2 in health-care workers and patients. FINDINGS: Between March 2 and March 12, 2020, 1796 (15%) of 12 022 health-care workers were screened, of whom 96 (5%) tested positive for SARS-CoV-2. We obtained complete and near-complete genome sequences from 50 health-care workers and ten patients. Most sequences were grouped in three clusters, with two clusters showing local circulation within the region. The noted patterns were consistent with multiple introductions into the hospitals through community-acquired infections and local amplification in the community. INTERPRETATION: Although direct transmission in the hospitals cannot be ruled out, our data do not support widespread nosocomial transmission as the source of infection in patients or health-care workers. FUNDING: EU Horizon 2020 (RECoVer, VEO, and the European Joint Programme One Health METASTAVA), and the National Institute of Allergy and Infectious Diseases, National Institutes of Health.

Prevalence and Clinical Presentation of Health Care Workers With Symptoms of Coronavirus Disease 2019 in 2 Dutch Hospitals During an Early Phase of the Pandemic.

Importance: On February 27, 2020, the first patient with coronavirus disease 2019 (COVID-19) was reported in the Netherlands. During the following weeks, at 2 Dutch teaching hospitals, 9 health care workers (HCWs) received a diagnosis of COVID-19, 8 of whom had no history of travel to China or northern Italy, raising the question of whether undetected community circulation was occurring. Objective: To determine the prevalence and clinical presentation of COVID-19 among HCWs with self-reported fever or respiratory symptoms. Design, Setting, and Participants: This cross-sectional study was performed in 2 teaching hospitals in the southern part of the Netherlands in March 2020, during the early phase of the COVID-19 pandemic. Health care workers employed in the participating hospitals who experienced fever or respiratory symptoms were asked to voluntarily participate in a screening for infection with the severe acute respiratory syndrome coronavirus 2. Data analysis was performed in March 2020. Main Outcomes and Measures: The prevalence of severe acute respiratory syndrome coronavirus 2 infection was determined by semiquantitative real-time reverse transcriptase-polymerase chain reaction on oropharyngeal samples. Structured interviews were conducted to document symptoms for all HCWs with confirmed COVID-19. Results: Of 9705 HCWs employed (1722 male [18%]), 1353 (14%) reported fever or respiratory symptoms and were tested. Of those, 86 HCWs (6%) were infected with severe acute respiratory syndrome coronavirus 2 (median age, 49 years [range, 22-66 years]; 15 [17%] male), representing 1% of all HCWs employed. Most HCWs experienced mild disease, and only 46 (53%) reported fever. Eighty HCWs (93%) met a case definition of fever and/or coughing and/or shortness of breath. Only 3 (3%) of the HCWs identified through the screening had a history of travel to China or northern Italy, and 3 (3%) reported having been exposed to an inpatient with a known diagnosis of COVID-19 before the onset of symptoms. Conclusions and Relevance: Within 2 weeks after the first Dutch case was detected, a substantial proportion of HCWs with self-reported fever or respiratory symptoms were infected with severe acute respiratory syndrome coronavirus 2, likely as a result of acquisition of the virus in the community during the early phase of local spread. The high prevalence of mild clinical presentations, frequently not including fever, suggests that the currently recommended case definition for suspected COVID-19 should be used less stringently.

Prevalence of nasal carriage of methicillin-resistant Staphylococcus aureus in patients at hospital admission in The Netherlands, 2010-2017: an observational study.

OBJECTIVES: We determined the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) nasal carriage upon hospital admission, among patients who were screened preoperatively for nasal S. aureus carriage between 2010 and 2017. We also aimed to evaluate the prevalence of MRSA carriers without the standard risk factors. METHODS: We conducted an observational study to determine the prevalence of MRSA nasal carriage among patients who were screened preoperatively for nasal S. aureus carriage between 2010 and 2017. Samples of cardiothoracic patients were tested by polymerase chain reaction (PCR), other samples were cultured using chromogenic agar plates. A Poisson regression model with robust error variance was used to assess whether there was a trend in the prevalence of MRSA over time. RESULTS: In total, 31 093 nasal swabs were obtained from 25 660 patients. Three-hundred and seventy-five swabs (1.2%) had an invalid result. Therefore, 30 718 swabs (98.8%) were included in our analysis. Overall, S. aureus was detected in 7981/30 718 patients (26.0% 95% CI 25.5-26.5%) of whom 41 were MRSA (0.13% 95% CI 0.10-0.18%). The MRSA prevalence varied from 0.03% to 0.17% over the years without evidence of a changing trend over time (p = 0.40). Results of the questionnaire revealed that 30 of the 41 patients (73.2%) had no known risk factors for MRSA carriage (0.10%; 95% CI 0.07-0.14%). CONCLUSION: Our study revealed a sustained low prevalence of MRSA carriage upon hospital admission over 7 years. This supports the effectiveness of the Dutch Search and Destroy policy, in combination with a restrictive antibiotic prescription policy.

Tonsillectomy for persistent MRSA carriage in the throat-Description of three cases.

In several countries, including the Netherlands, a search and destroy policy is part of the standard of care. Due to this policy and the restrictive use of antibiotics, the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) in the Netherlands - carrier state and infections - is among the lowest in the world. In the Netherlands, healthcare workers who are MRSA carriers are not allowed to perform work involving direct patient care. This means that treatment failure can have major implications for their working career. Despite repeated treatments according to guidelines, the eradication of MRSA fails in a minority of cases. It appears that performing a tonsillectomy can be part of the solution to this problem. As yet, tonsillectomy is not recommended as supplementary treatment for persistent MRSA carriage in the throat. There are a few expert opinions suggesting that tonsillectomy could possibly be helpful in decolonization. This article reports three recent cases in which MRSA eradication was successful only after tonsillectomy. It is believed that if eradication is necessary, tonsillectomy, if applicable, should be considered.

Proton Pump Inhibitor Use Is Associated With Extended-Spectrum ß-Lactamase-Producing Enterobacteriaceae Rectal Carriage at Hospital Admission: A Cross-Sectional Study.

In this cross-sectional study, 8.5% of patients using proton pump inhibitors (PPIs) were rectal carriers of extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E), compared with 2.9% of non-PPI users. In multivariable analysis, PPI use was independently associated with ESBL-E rectal carriage at hospital admission (adjusted odds ratio, 3.89; 95% confidence interval, 1.65 - 9.19).

New WHO recommendations on preoperative measures for surgical site infection prevention: an evidence-based global perspective.

Surgical site infections (SSIs) are among the most preventable health-care-associated infections and are a substantial burden to health-care systems and service payers worldwide in terms of patient morbidity, mortality, and additional costs. SSI prevention is complex and requires the integration of a range of measures before, during, and after surgery. No international guidelines are available and inconsistencies in the interpretation of evidence and recommendations of national guidelines have been identified. Given the burden of SSIs worldwide, the numerous gaps in evidence-based guidance, and the need for standardisation and a global approach, WHO decided to prioritise the development of evidence-based recommendations for the prevention of SSIs. The guidelines take into account the balance between benefits and harms, the evidence quality, cost and resource use implications, and patient values and preferences. On the basis of systematic literature reviews and expert consensus, we present 13 recommendations on preoperative preventive measures.

Long-term Mortality After Rapid Screening and Decolonization of Staphylococcus Aureus Carriers: Observational Follow-up Study of a Randomized, Placebo-controlled Trial.

OBJECTIVE: To identify patients who benefit most from Staphylococcus aureus screening and decolonization treatment upon admission. BACKGROUND: S. aureus carriers are at increased risk of developing surgical-site infections with S. aureus. Previously, we demonstrated in a randomized, placebo-controlled trial (RCT) that these infections can largely be prevented by detection of carriage and decolonization treatment upon admission. In this study, we analyzed 1- and 3-year mortality rates in both treatment arms of the RCT to identify patient groups that should be targeted when implementing the screen-and-treat strategy. METHODS: Three years after enrolment in the RCT, mortality dates of all surgical patients were checked. One- and 3-year mortality rates were calculated for all patients and for various subgroups. RESULTS: After 3 years, 44 of 431 (10.2%) and 43 of 362 (11.9%) patients had died in the mupirocin/chlorhexidine and placebo groups, respectively. No significant differences in mortality rates were observed between the treatment groups or the subgroups according to type of surgery. In the subgroup of patients with clean procedures (382 cardiothoracic, 167 orthopedic, 61 vascular, and 56 other), mupirocin/chlorhexidine reduced 1-year mortality: 11 of 365 (3.0%) died in the mupirocin/chlorhexidine versus 21 of 301 (7.0%) in the placebo group [hazard ratio = 0.38 (95% CI: 0.18-0.81)]. CONCLUSIONS: Detection and decolonization of S. aureus carriage not only prevents S. aureus surgical-site infections but also reduces 1-year mortality in surgical patients undergoing clean procedures. Such patients with a high risk of developing S. aureus infections should therefore be the primary target when implementing the screen-and-treat strategy in clinical practice.

Livestock-associated MRSA in household members of pig farmers: transmission and dynamics of carriage, a prospective cohort study.

This prospective cohort study describes carriage of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in household members from 49 farrowing pig farms in the Netherlands (2010-2011). Of 171 household members, 4% were persistent MRSA nasal carriers, and the MRSA prevalence on any given sampling moment was 10% (range 7-11%). Working in the stables (of which 98% was MRSA-positive, prevalence ratio (PR) = 2.11 per 10 hours), working with sows (PR=1.97), and living with an MRSA-positive pig farmer (PR=4.63) were significant determinants for MRSA carriage. Significant protective factors were carriage of methicillin-susceptible Staphylococcus aureus (MSSA) (PR=0.50), and wearing a facemask when working in the stables (37% decreased prevalence). All MRSA strains during the study period were known livestock-associated types. The bacteriophage φ3 was not found in household members. Transmission from pigs and the environment appeared to be important determinants; human-to-human transmission could not sufficiently be differentiated. Wearing a facemask when working in the stables and carriage of MSSA are potential interventional targets.

Genome-wide analysis reveals two novel mosaic regions containing an ACME with an identical DNA sequence in the MRSA ST398-t011 and MSSA ST8-t008 isolates.

OBJECTIVES: The presence of the arginine catabolic mobile element (ACME) in Staphylococcus aureus has been reported to enhance the colonization of the human host. The aim of this study was to determine the genetic organization of composite islands harbouring ACME. METHODS: Two ACME-positive S. aureus isolates obtained during two different surveys conducted in the Netherlands and Poland were characterized in this study. The isolates were analysed by spa typing, DNA microarrays and whole-genome sequencing. RESULTS: The two isolates harboured a truncated yet fully functional ACME type II with an identical nucleotide sequence, but differed in their adjacent mobile genetic elements. The first strain was a livestock-associated ST398-t011 MRSA, which had a staphylococcal cassette chromosome mec (SCCmec) composite island composed of SCCpls adjacent to orfX followed by ACME type II and SCCmec type IVa. The second ACME-positive isolate was an ST8-t008 MSSA. Its composite island showed an SCC-like element carrying the ccrC gene followed by ACME II. CONCLUSIONS: This is the first report of an ACME in a livestock-associated MRSA ST398. It is also the first presentation of an ACME composite island structure in an MSSA isolate. Our findings indicate an extensive mosaicism of composite islands in S. aureus, which has implications for the transmissibility among humans and thus for public health.

Transmission of methicillin-resistant Staphylococcus aureus CC398 from livestock veterinarians to their household members.

There are indications that livestock-associated MRSA CC398 has a reduced human-to-human transmissibility, limiting its impact on public health and justifying modified control measures. This study determined the transmissibility of MRSA CC398 from livestock veterinarians to their household members in the community as compared to MRSA non-CC398 strains. A one-year prospective cohort study was performed to determine the presence of MRSA CC398 in four-monthly nasal and oropharyngeal samples of livestock veterinarians (n  =  137) and their household members (n  =  389). In addition, a cross-sectional survey was performed to detect the presence of MRSA non-CC398 in hospital derived control patients (n  =  20) and their household members (n  =  41). Staphylococcus aureus isolates were genotyped by staphylococcal protein A (spa) typing and multiple-locus variable-number tandem repeat analysis (MLVA). Mean MRSA CC398 prevalence over the study period was 44% (range 41.6-46.0%) in veterinarians and 4.0% (range 2.8-4.7%) in their household members. The MRSA CC398 prevalence in household members of veterinarians was significantly lower than the MRSA non-CC398 prevalence in household members of control patients (PRR 6.0; 95% CI 2.4-15.5), indicating the reduced transmissibility of MRSA CC398. The impact of MRSA CC398 appears to be low at the moment. However, careful monitoring of the human-to-human transmissibility of MRSA CC398 remains important.

Livestock-associated MRSA carriage in patients without direct contact with livestock.

BACKGROUND: Livestock-associated MRSA (MC398) has emerged and is related to an extensive reservoir in pigs and veal calves. Individuals with direct contact with these animals and their family members are known to have high MC398 carriage rates. Until now it was assumed that MC398 does not spread to individuals in the community without pig or veal calf exposure. To test this, we identified the proportion of MC398 in MRSA positive individuals without contact with pigs/veal calves or other known risk factors (MRSA of unknown origin; MUO). METHODS: In 17 participating hospitals, we determined during two years the occurrence of MC398 in individuals without direct contact with livestock and no other known risk factor (n = 271) and tested in a post analysis the hypothesis whether hospitals in pig-dense areas have higher proportions of MC398 of all MUO. RESULTS: Fifty-six individuals (20.7%) without animal contact carried MC398. In hospitals with high pig-densities in the adherence area, the proportion of MC398 of all MUO was higher than this proportion in hospitals without pigs in the surroundings. CONCLUSIONS: One fifth of the individuals carrying MUO carried MC398. So, MC398 is found in individuals without contact to pigs or veal calves. The way of transmission from the animal reservoir to these individuals is unclear, probably by human-to-human transmission or by exposure to the surroundings of the stables. Further research is needed to investigate the way of transmission.

Adjustment of the MRSA Search and Destroy policy for outpatients in the Netherlands: a prospective cohort study with repeated prevalence measurements.

BACKGROUND: In the Netherlands a successful MRSA Search and Destroy policy is applied in healthcare institutes. We determined the effect of an adjustment in the MRSA Search and Destroy policy for patients in the outpatient clinic on the MRSA transmission to health care workers (HCW). METHODS: In June 2008 an adjustment in the policy for outpatients was introduced in a large teaching hospital. Following this adjustment MRSA positive patients and patients at risk could be seen and treated applying general precautions, without additional protective measures. Also, disinfection of the room after the patient had left was abandoned. To monitor the effect of this policy on the transmission of MRSA all physicians and health care workers of the outpatient clinic were screened for MRSA carriage repeatedly. RESULTS: Before the introduction of the adjusted policy all physicians and HCW of the outpatient clinic were screened (=0-measurement, n = 1,073). None of them was found to be MRSA positive. After introduction of the policy in June 2008 the screening was repeated in October 2008 (n = 1,170) and April 2009 (n = 1,128). In April 2009 one health care worker was MRSA positive resulting in a mean prevalence of 0.09%. This is lower than the known prevalence in HCW. The health care worker was colonized with the livestock-related Spa type t011. As far as we could verify, no patients with this Spa-type had been cared for by the health care worker. CONCLUSIONS: The adjusted MRSA policy did not lead to detectable transmission of MRSA to HCW and was associated with less disturbances in the work flow.

Antibiotic susceptibility and molecular epidemiology of Panton-Valentine leukocidin-positive meticillin-resistant Staphylococcus aureus: An international survey.

The antibiotic susceptibility and molecular epidemiology of Panton-Valentine leukocidin (PVL)-positive meticillin-resistant Staphylococcus aureus (MRSA) isolates reported from 17 countries in the Americas, Europe and, Australia-Asia were analysed. Among a total of 3236 non-duplicate isolates, the lowest susceptibility was observed to erythromycin in all regions. Susceptibility to ciprofloxacin showed large variation (25%, 75% and 84% in the Americas, Europe and Australia-Asia, respectively). Two vancomycin-intermediate PVL-positive MRSA isolates were reported, one from Hong Kong and the other from The Netherlands. Resistance to trimethoprim/sulfamethoxazole and linezolid was <1%. Among 1798 MRSA isolates from 13 countries that were tested for the requested 10 non-ß-lactam antibiotics, 49.4% were multisusceptible. However, multiresistant isolates (resistant to at least three classes of non-ß-lactam antibiotics) were reported from all regions. Sequence type 30 (ST30) was reported worldwide, whereas ST80 and ST93 were exclusive to Europe and Australia, respectively. USA300 and related clones (ST8) are progressively replacing the ST80 clone in several European countries. Eight major clusters were discriminated by multilocus variable-number tandem repeat assay (MLVA), showing a certain geographic specificity. PVL-positive MRSA isolates frequently remain multisusceptible to non-ß-lactam agents, but multiresistance is already prevalent in all regions. Surveillance of MRSA susceptibility patterns should be monitored to provide clinicians with the most current information regarding changes in resistance patterns.

Lifestyle-Associated Risk Factors for Community-Acquired Methicillin-Resistant Staphylococcus aureus Carriage in the Netherlands: An Exploratory Hospital-Based Case-Control Study.

BACKGROUND: Community-acquired MRSA (CA-MRSA) is rapidly increasing. Currently, it is unknown which reservoirs are involved. An exploratory hospital-based case-control study was performed in sixteen Dutch hospitals to identify risk factors for CA-MRSA carriage in patients not belonging to established risk groups. METHODS: Cases were in- or outpatients from sixteen Dutch hospitals, colonised or infected with MRSA without healthcare- or livestock-associated risk factors for MRSA carriage. Control subjects were patients not carrying MRSA, and hospitalised on the same ward or visited the same outpatients' clinic as the case. The presence of potential risk factors for CA-MRSA carriage was determined using a standardised questionnaire. RESULTS: Regular consumption of poultry (OR 2⋅40; 95% CI 1⋅08-5⋅33), cattle density per municipality (OR 1⋅30; 95% CI 1⋅00-1⋅70), and sharing of scuba diving equipment (OR 2⋅93 95% CI 1⋅19-7⋅21) were found to be independently associated with CA-MRSA carriage. CA-MRSA carriage was not related to being of foreign origin. CONCLUSIONS: The observed association between the consumption of poultry and CA-MRSA carriage suggests that MRSA in the food chain may be a source for MRSA carriage in humans. Although sharing of scuba diving equipment was found to be associated with CA-MRSA carriage, the role played by skin abrasions in divers, the lack of decontamination of diving materials, or the favourable high salt content of sea water is currently unclear. The risk for MRSA MC398 carriage in areas with a high cattle density may be due to environmental contamination with MRSA MC398 or human-to-human transmission. Further studies are warranted to confirm our findings and to determine the absolute risks of MRSA acquisition associated with the factors identified.

Dynamics and determinants of Staphylococcus aureus carriage in livestock veterinarians: a prospective cohort study.

BACKGROUND: Since 2003, a new clade of methicillin-resistant Staphylococcus aureus (MRSA) belonging to clonal complex (CC) 398 and associated with animal husbandry has emerged in the Netherlands. The purpose of this study was to determine the dynamics of carriage in persons with direct contact to livestock. METHODS: A 2-year prospective cohort study was performed in which the anterior nares and oropharynx of 137 livestock veterinarians were sampled for the presence of S. aureus every 4 months during the first year and again 1 year later. All S. aureus isolates were genotyped by staphylococcal protein A (spa) typing and with multilocus variable-number tandem repeat analysis (MLVA). RESULTS: The mean prevalence of MRSA CC398 carriage was 44% (range, 42%-46%), and for S. aureus the prevalence was 72% (range, 69%-75%). Thirty-two veterinarians (23%) were always carrying MRSA CC398 and 18 of those (56%, 13% of all veterinarians) had identical MLVA types at all sampling moments. CONCLUSIONS: A high proportion of veterinarians had persistent MRSA CC398 carriage during the 2-year study period, indicating that this variant may colonize humans for prolonged periods. Furthermore, prevalence of S. aureus carriage was extremely high, indicating that MRSA CC398 is not replacing the susceptible strains, but comes on top of it.

Self-sampling is appropriate for detection of Staphylococcus aureus: a validation study.

BACKGROUND: Studies frequently use nasal swabs to determine Staphylococcus aureus carriage. Self-sampling would be extremely useful in an outhospital research situation, but has not been studied in a healthy population. We studied the similarity of self-samples and investigator-samples in nares and pharynxes of healthy study subjects (hospital staff) in the Netherlands. METHODS: One hundred and five nursing personnel members were sampled 4 times in random order after viewing an instruction paper: 1) nasal self-sample, 2) pharyngeal self-sample, 3) nasal investigator-sample, and 4) pharyngeal investigator-sample. RESULTS: For nasal samples, agreement is 93% with a kappa coefficient of 0.85 (95% CI 0.74-0.96), indicating excellent agreement, for pharyngeal samples agreement is 83% and the kappa coefficient is 0.60 (95% CI 0.43-0.76), indicating good agreement. In both sampling sites self-samples even detected more S. aureus than investigator-samples. CONCLUSIONS: This means that self-samples are appropriate for detection of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.

Reduced costs for Staphylococcus aureus carriers treated prophylactically with mupirocin and chlorhexidine in cardiothoracic and orthopaedic surgery.

BACKGROUND: A multi centre double-blind randomised-controlled trial (M-RCT), carried out in the Netherlands in 2005-2007, showed that hospitalised patients with S. aureus nasal carriage who were treated prophylactically with mupirocin nasal ointment and chlorhexidine gluconate medicated soap (MUP-CHX), had a significantly lower risk of health-care associated S. aureus infections than patients receiving placebo (3.4% vs. 7.7%, RR 0.42, 95% CI 0.23-0.75). The objective of the present study was to determine whether treatment of patients undergoing elective cardiothoracic or orthopaedic surgery with MUP-CHX (screen-and-treat strategy) affected the costs of patient care. METHODS: We compared hospital costs of patients undergoing cardiothoracic or orthopaedic surgery (n=415) in one of the participating centres of the M-RCT. Data from the 'Planning and Control' department were used to calculate total hospital costs of the patients. Total costs were calculated including nursing days, costs of surgery, costs for laboratory and radiological tests, functional assessments and other costs. Costs for personnel, materials and overhead were also included. Mean costs in the two treatment arms were compared using the t-test for equality of means (two-tailed). Subgroup analysis was performed for cardiothoracic and orthopaedic patients. RESULTS: An investigator-blinded analysis revealed that costs of care in the treatment arm (MUP-CHX, n=210) were on average €1911 lower per patient than costs of care in the placebo arm (n=205) (€8602 vs. €10513, p=0.01). Subgroup analysis showed that MUP-CHX treated cardiothoracic patients cost €2841 less (n=280, €9628 vs €12469, p=0.006) and orthopaedic patients €955 less than non-treated patients (n=135, €6097 vs €7052, p=0.05). CONCLUSIONS: In conclusion, in patients undergoing cardiothoracic or orthopaedic surgery, screening for S. aureus nasal carriage and treating carriers with MUP-CHX results in a substantial reduction of hospital costs.

Mupirocin ointment for preventing Staphylococcus aureus infections in nasal carriers.

BACKGROUND: Staphylococcus aureus (S. aureus) is the leading nosocomial (hospital acquired) pathogen in hospitals throughout the world. Traditionally, control of S. aureus has been focused on preventing cross-infection between patients, however, it has been shown repeatedly that a large proportion of nosocomial S. aureus infections originate from the patient's own flora. Nasal carriage of S. aureus is now considered a well defined risk factor for subsequent infection in various groups of patients. Local antibiotic treatment with mupirocin ointment is often used to eradicate nasal S. aureus. OBJECTIVES: To determine whether the use of mupirocin nasal ointment in patients with identified S. aureus nasal carriage reduced S. aureus infection rates. SEARCH STRATEGY: We searched the Cochrane Wounds Group Specialised Register (May 2008), the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 2 2008), MEDLINE (1950 to May 2008), EMBASE (1980 to May 2008) and CINAHL (1982 to May 2008). To identify unpublished trials, abstract books from major scientific meetings (ICAAC, ESCMID and SHEA) were handsearched, researchers and manufacturers of mupirocin were contacted and other electronic databases were searched (SIGLE, ASLIB Index, mRCT, USA Clinical Trials). SELECTION CRITERIA: Randomised controlled trials (RCTs) comparing nasal mupirocin with no treatment or placebo or alternative nasal treatment in the prevention of S. aureus infections in nasal S. aureus carriers were included. DATA COLLECTION AND ANALYSIS: Titles, abstracts and full-text articles of studies retrieved from the search process were independently assessed by two authors for inclusion. From included studies a data extraction form was made and the quality of the trial was assessed. The primary outcome was the S. aureus infection rate (any site). Secondary outcomes were time to infection, mortality, adverse events and infection rate caused by micro-organisms other than S. aureus. MAIN RESULTS: Nine RCTs involving 3396 participants met the inclusion criteria. Patient populations varied and several types of nosocomial S. aureus infection were described including bacteraemia, exit-site infections, peritonitis, respiratory tract infections, skin infections, surgical site infections (SSI) and urinary tract infections. After pooling the eight studies that compared mupirocin with placebo or with no treatment, there was a statistically significant reduction in the rate of S. aureus infection associated with intranasal mupirocin (RR 0.55, 95% CI 0.43 to 0.70).A planned subgroup analysis of surgical trials demonstrated a significant reduction in the rate of nosocomial S. aureus infection rate associated with mupirocin use (RR 0.55, 95% CI 0.34 to 0.89) however this effect disappeared if the analysis only included surgical site infections caused by S. aureus (RR 0.63, 95% CI 0.38 to 1.04), possibly due to a lack of power. The infection rate caused by micro-organisms other than S. aureus was significantly higher in patients treated with mupirocin compared with control patients (RR 1.38 95% CI 1.118 to 1.72). AUTHORS' CONCLUSIONS: In people who are nasal carriers of S. aureus, the use of mupirocin ointment results in a statistically significant reduction in S. aureus infections.

New approaches to prevention of staphylococcal infection in surgery.

PURPOSE OF REVIEW: The present review describes the literature about the prevention of Staphylococcus aureus infections in surgery, published from August 2006 to January 2008, and puts it into perspective. RECENT FINDINGS: To prevent Staphylococcus aureus infections after surgical procedures, three methods were described, that is, isolation precautions after methicillin-resistant Staphylococcus aureus screening, vancomycin as an antibiotic prophylaxis in patients at risk for methicillin-resistant Staphylococcus aureus, and topical decolonization of carriage. Identified methicillin-resistant Staphylococcus aureus carriers can be treated with the appropriate antibiotic prophylaxis to prevent infection with methicillin-resistant Staphylococcus aureus. Topical decolonization with chlorhexidine gluconate resulted in a reduced overall nosocomial infection rate, but no effect was found on the Staphylococcus aureus infection rate. Topical decolonization with mupirocin reduced the overall Staphylococcus aureus infection rate after surgery in Staphylococcus aureus nasal carriers. SUMMARY: The treatment of proven carriers of Staphylococcus aureus with mupirocin is an effective method to prevent Staphylococcus aureus nosocomial infections after surgery. Cost-analysis studies show that this screen-and-treat approach is cost saving as long as the prevalence of mupirocin resistance in Staphylococcus aureus is low. The effect of chlorhexidine gluconate on the Staphylococcus aureus infection rate in carriers should be determined in future studies.