Methicillin-resistant Staphylococcus aureus bacteraemia in neonatal intensive care units: an analysis of 90 episodes

Successful control of a Methicillin-resistant Staphylococcus aureus outbreak in a neonatal intensive care unit: a retrospective, before-after study

Background

Aim of this study was to provide a detailed description of a Methicillin-resistant Staphylococcus aureus (MRSA) outbreak management strategy in the neonatal intensive care unit of a university hospital.

Methods

This was a retrospective, “before-after” study, over two consecutive 18-month periods. The outbreak management strategy was performed by a multidisciplinary team and included: extensive healthcare workers (HCW) involvement, education, continuous hand-hygiene training and active MRSA colonization surveillance. The actions implemented were identified based on an anonymous, voluntary, reporting system, carried out among all the HCW, and regular audit and feedback were provided to the nursing staff.

The main measured outcome was the rate of MRSA infections before and after the implementation of the outbreak management strategy. Piecewise linear Poisson regression was performed and the model adjusted for confounding variables. The secondary outcome was the rate of laboratory-confirmed bloodstream infections before and after the outbreak management strategy. The rates of MRSA colonization, implementation of proposed actions, observed compliance for hand-hygiene and insertion/care of central lines were also recorded during the second period.

Results

1015 newborns were included. The rate of MRSA infections throughout the two periods fell from 3.5 to 0.7 cases per 1000 patient-days (p=0.0005). The piecewise Poisson regression analysis adjusted for confounding variables showed a significant decrease in the MRSA infection rate after the outbreak management strategy (p=0.046). A significant decrease in positive laboratory confirmed blood cultures was observed over the two periods (160 vs 83; p<0.0001). A significant decline in the MRSA colonization rate occurred over the second period (p=0.001); 93% of the proposed actions were implemented. The compliance rate for hand-hygiene and insertion/care of central lines was respectively 95.9% and 62%.

Conclusions

The implementation of multiple, simultaneous, evidence-based management strategies is effective for controlling nosocomial infections. Outbreak management strategies may benefit from tools improving the communication between the institutional and scientific leadership and the ground-level staff. These measures can help to identify individualized solutions addressing specific unit needs.

Impact of Methicillin-Resistance on Mortality in Children and Neonates with Staphylococcus aureus Bacteremia: A Meta-analysis

Background

Staphylococcus aureus bacteremia (SAB) is the Staphylococcal infections in blood, one of the most common and fatal bacterial infectious diseases worldwide in adults as well as children or neonates. Recently, some studies have yielded inconsistent findings about the association between methicillin-resistance and mortality in patients with SAB. We performed a meta-analysis to assess the impact of methicillin-resistance on mortality in children or neonates with S. aureus bacteremia.

Materials and Methods

We searched using electronic databases such as Ovid-Medline, EMBASE-Medline, and Cochrane Library, as well as five local databases for published studies during the period of 1 January 2000 to 15 September 2011. Two reviewers independently selected articles in accordance with predetermined criteria and extracted prespecified data based on standardized forms. All cohort studies, which compared in-hospital mortality or SAB-related mortality in children and neonates with methicillin-resistant S. aureus (MRSA) infection to those with methicillin-susceptible S. aureus (MSSA), were included. We conducted meta-analysis using the fixed-effect model to obtain pooled estimates of effect.

Results

Of 2,841 screened studies, seven cohort studies were finally selected for analysis. In children or neonates, MRSA bacteremia was associated with a higher mortality compared with MSSA bacteremia (pooled odds ratio [OR] 2.33, P = 0.0008, 95% confidence interval [CI] 1.42 to 3.82, I² = 0%). Four studies reported SAB-related mortality, the pooled OR of these studies was 2.03 (P = 0.29, 95% CI 0.55 to 7.53, I² = 0%). A significant increase in mortality associated with methicillin resistance was found in the subgroup analyses of the studies with only neonates (OR: 2.66, 95% CI: 1.46 to 4.85, P = 0.001), prospectively design ones (OR: 3.20, 95% CI: 1.66 to 6.15, P = 0.0005,), the larger studies (OR: 2.89, 95% CI: 1.62 to 5.16, P = 0.0003) and the higher quality studies (OR: 2.76, 95% CI: 1.50 to 5.06, P = 0.001).

Conclusions

MRSA bacteremia is associated with increased mortality compared with MSSA bacteremia in children or neonates. Due to limited studies for mortality in children or neonates with SAB, further research is needed to evaluate the impact of methicillin resistance on mortality in those populations.

Staphylococcus aureus bloodstream infections in children: A population-based assessment

BACKGROUND

Although Staphylococcus aureus is a major cause of bloodstream infections, population-based data on these infections in children are limited.

OBJECTIVE

To describe the epidemiology of S aureus bacteremia in children.

METHODS

Population-based surveillance for all incident S aureus bacteremias was conducted among children (18 years of age or younger) living in the Calgary Health Region (Alberta) from 2000 to 2006.

RESULTS

During the seven-year study, 120 S aureus bloodstream infections occurred among 119 patients; 27% were nosocomial, 18% health care associated and 56% community acquired. The annual incidence was 6.5/100,000 population and 0.094/1000 live births. A total of 52% had a significant underlying condition, and this was higher for nosocomial cases. Bone and joint (40%), bacteremia without a focus (33%), and skin and soft tissue infections (15%) were the most common clinical syndromes. Infections due to methicillin-resistant S aureus were uncommon (occurring in one infection) and three patients (2.5%) died.

CONCLUSIONS

S aureus bacteremia is an important cause of morbidity in the paediatric age group. Underlying medical conditions and implanted devices are important risk factors. Methicillin-resistant S aureus and mortality rates are low.

Successful control of methicillin-resistant Staphylococcus aureus in endemic neonatal intensive care units--a 7-year campaign

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is among the most important nosocomial pathogens in the intensive care unit (ICU) worldwide, including Taiwan. Since 1997, our neonatal ICUs (NICUs) had become endemic for MRSA.

Methodology/Principal Findings

To control MRSA spread in our NICUs, we implemented a series of infection control measures stepwise, including reinforcement of hand hygiene since January 2000, augmentation of aseptic care over the insertion site of central venous catheter since July 2001, introduction of alcohol-based handrubs since April 2003, surveillance culture for MRSA and cohort care for the colonized patients between March 2003 and February 2004, and surveillance culture with subsequent decolonization of MRSA between August 2005 and July 2006. After implementation of these measures, MRSA healthcare-associated infection (HAI) density reduced by 92%, from 5.47 episodes per 1000 patient-days in 1999 to 0.45 episodes per 1000 patient-days in 2006; MRSA bloodstream infection reduced from 40 cases in 1999 to only one case in 2006. Compared to those obtained during the period of surveillance culture without decolonization, both rates of MRSA colonization (8.6% vs. 41%, p<0.001) and infection (1.1% vs. 12%, p<0.001) decreased significantly during the period of surveillance and decolonization. Molecular analysis of the clinical isolates during the study period showed that the endemic clone, which dominated between 1998 and 2005, almost disappeared in 2006, while the community clones increased significantly in 2006–2007.

Conclusion/Significance

Through infection control measures, MRSA HAIs can be successfully controlled, even in areas with high levels of endemic MRSA infections such as our NICUs.

Methicillin-resistant Staphylococcus aureus: prevalence and current susceptibility pattern in sikkim

Background:

Prevalence of methicillin-resistant Staphylococcus Aureus (MRSA) strains is reported to be increasing globally.

Objectives:

The study was conducted to find the magnitude and antibiotic susceptibility pattern of MRSA infection in a referral tertiary care teaching hospital of Sikkim, India.

Materials and Methods:

In this cross sectional study, 827 clinical specimens were collected from different departments of Central Referral Hospital. One hundred and ninety-six carrier screening nasal swabs were obtained from health care workers of the hospital. Subsequently, the antimicrobial susceptibility test was performed for the confirmed MRSA isolates as per Clinical and Laboratory Standards Institute (CLSI).

Results:

Methicillin resistance was seen in 152 isolates of S. aureus – 111 from clinical specimens and 41 from carrier screening samples. MRSA positivity among males was significantly higher than females. Extremely significant MRSA-positive cases were observed from ages less than 30 years, in-patient cases, particularly with a stay of more than 15 days and with a previous history of intake of broad spectrum antibiotics. Incidentally, there was no significant difference of MRSA positivity with a previous history of hospitalization. The extent of MRSA and drug resistance pattern was significantly different among various samples of S. aureus-positive isolates. The strains tested exhibited decreased susceptibility to vancomycin and imipenem. Most vulnerable of the carrier were the cleaners, that was a significant observation. Incidentally, there was no resistance in the carriers to both vancomycin and imipenem.

Conclusion:

MRSA is prevalent in our hospital and strains resistant to methicillin and vancomycin were quite high.

Catheter-related bloodstream infection with removal of catheter in pediatric oncology patients: a 10-year experience in Taiwan

BACKGROUND

Long-term central venous catheter (CVC) implantation has become more affordable in Taiwan since 1995. Surgical removal of the catheter may be the essential treatment for catheter-related bloodstream infections (CRBSI). The aim of this study was to evaluate the clinical features and microbial isolates in pediatric cancer patients with removal of CVC for CRBSI.

PROCEDURE

The records of positive blood culture from hospitalized pediatric oncology patients between 1995 and 2004 were reviewed. One hundred and forty-three patients implanted with a long-term CVC were further identified.

RESULTS

Seventeen catheters in 16 patients developed catheter-related bacteremia that needed catheter removal. The rate of catheter removal was 11.9%. The median device life was 7.7 months. Six catheters were removed within 3 months of insertion. Nine of the 17 catheters were removed from patient younger than 2 years. Eight infections occurred during severe neutropenia, and 6 patients had refractory or relapsed underlying disease. The cultural isolates were Gram-negative bacilli in 7, Gram-positive in 5, fungi in 5, and atypical mycobacterium in 1. The frequency of catheter removal for infection control was significantly higher in the first 5 years (1994-1999) compared to the last 5 years (2000-2004) (30.9 vs. 4.0%, p = 2.3 × 10(-4)).

CONCLUSIONS

Factors such as microbiological isolates, age of infection, the status of malignancy, and neutropenia are related to catheter outcome. The reduction in patients with positive cultures needing removal of the catheters can be related to improved nursing care and more aggressive antibiotic therapy.

Successful management of an MRSA outbreak in a neonatal intensive care unit

We report an MRSA outbreak in our 25-bed tertiary neonatal intensive care unit (NICU), which was successfully contained. Methods include a retrospective review of patient files, microbiology records and meeting protocols. During the seven months of outbreak, 27 patients and seven health care workers (HCWs) had positive cultures for MRSA. The outbreak was caused by the epidemic Rhine-Hessen strain; cultured isolates were monoclonal. After a sharp increase of the number of new MRSA-cases the installation of an outbreak management team (OMT) and implementation of comprehensive measures (extensive screening and decolonization strategy including orally applied vancomycin, isolation wards, intensive disinfection regimen) successfully terminated the outbreak within one month. Ten (53%) of 19 patients with completed follow-up and all of the HCWs were decolonized successfully. Gastrointestinal colonization was present in 15 of 27 (56%) neonates, and was associated with poor decolonization success (30% vs. 78% in absence of gastrointestinal colonization). A comprehensive outbreak management can terminate an outbreak in a NICU setting within a short time. Thorough screening of nares, throat and especially stool is necessary for correct cohorting. Gastrointestinal decolonization in neonates seems difficult.

The potential economic value of a Staphylococcus aureus vaccine for neonates

The continuing morbidity and mortality associated with Staphylococcus aureus (S. aureus) infections, especially methicillin-resistant S. aureus (MRSA) infections, have motivated calls to make S. aureus vaccine development a research priority. We developed a decision analytic computer simulation model to determine the potential economic impact of a S. aureus vaccine for neonates. Our results suggest that a S. aureus vaccine for the neonatal population would be strongly cost-effective (and in many situations dominant) over a wide range of vaccine efficacies (down to 10%) for vaccine costs (or=1%).

Changing trend of neonatal infection: experience at a newly established regional medical center in Korea

BACKGROUND

The purpose of the present paper was to study the natural history of neonatal sepsis in a newly established neonatal intensive care center that started in 1988 at Gyeongsang National University Hospital 9 (GNUH) in Chinju city, Korea.

METHODS

Neonates admitted to GNUH neonatal intensive care unit (NICU) between January 1988 and December 1997 were included. All organisms detected on blood and cerebrospinal fluid cultures were recorded. Neonatal sepsis was defined as 'clinical signs suggestive of sepsis with a positive blood and/or cerebrospinal fluid culture during the neonatal period'. Temporal trends and the distribution of pathogens in identified septic patients during the aforementioned period were studied descriptively.

RESULTS

Between January 1988 and 31 December 1997, 3327 neonates were admitted to the center. A total of 6.7% of neonates (224/3327) had at least one positive blood culture. The vast majority (62%) of septic cases were caused by Gram-positive organisms. Coagulase-negative staphylococci (CONS) were the most common pathogens (24% of all infections, 38% of Gram-positive infections). The pathogen associated with the highest mortality was Klebsiella pneumoniae (25%, 10/39). Sepsis as a result of Gram-negative pathogens (especially K. pneumoniae) were involved in outbreaks that occurred for a few years during the study interval.

CONCLUSIONS

The major outcome of this review was the emergence of CONS in the NICU during a relatively short period of time (10 years) as a common neonatal pathogen. This observation is similar to the experience of other centers over the last two decades.