Use of surveillance cultures and enteral vancomycin to control methicillin-resistant Staphylococcus aureus in a paediatric intensive care unit

Enteral Vancomycin to Eliminate MRSA Carriership of the Digestive Tract in Critically Ill Patients

Background: Carriership with methicillin resistant Staphylococcus aureus (MRSA) is a risk for the development of secondary infections in critically ill patients. Previous studies suggest that enteral vancomycin is able to eliminate enteral carriership with MRSA. Data on individual effects of this treatment are lacking. Methods: Retrospective analysis of a database containing 15 year data of consecutive patients from a mixed medical-(cardio)surgical 18 bedded intensive care unit was conducted. All consecutive critically ill patients with enteral MRSA carriership detected in throat and/or rectal samples were collected. We analyzed those with follow-up cultures to determine the success rate of enteral vancomycin. Topical application of 2% vancomycin in a sticky oral paste was performed combined with a vancomycin solution of 500 mg four times daily in the nasogastric tube. This treatment was added to a regimen of selective digestive tract decontamination (SDD) to prevent ICU acquired infection. Results: Thirteen patients were included. The mean age was 65 years and the median APACHE II score was 21. MRSA was present in the throat in 8 patients and in both throat and rectum in 5 patients. In all patients MRSA was successfully eliminated from both throat and rectum, which took 2–11 days with a median duration until decontamination of 4 days. Secondary infections with MRSA did not occur. Conclusions: Topical treatment with vancomycin in a 2% sticky oral paste four times daily in the nasogastric tube was effective in all patients in the elimination of MRSA and prevented secondary MRSA infections.

Staphylococcus aureus Bacteremia in Children: Antibiotic Resistance and Mortality

BACKGROUND

Staphylococcus aureus (SA) is a major cause of bacteremia in children. Methicillin-resistant SA (MRSA) is considered a public health threat; however, the differences in the prognosis of children with methicillin-susceptible SA (MSSA) versus MRSA bacteremia are not well defined.

METHODS

Data from all SA bacteremia events in children (0-16 years) from 2002 to 2016 in a single Israeli tertiary center were collected. Positive cultures within 48 hours of hospitalization were considered community associated (CA). Those obtained afterward or from children hospitalized within the previous year were considered health-care associated (HA).

RESULTS

We recorded 427 events, 284 (66%) were HA, 64 (15%) were MRSA and 9 (2%) were CA-MRSA. There was no increase in MRSA during the study period. In-hospital, 30-day and 1-year mortality were 3% (12 cases), 3.5% (16 cases), and 12% (50 cases), respectively. A multivariable analysis controlling for demographics, admitting department and prior morbidity showed an increased 1-year mortality in children with HA bacteremia (hazard ratio [HR] 4.1; 95% confidence interval [CI]: 1.3-12) and prior chronic disease (HR 3.4; 95% CI 1.2 to 9.0). MRSA was not independently associated with increased one-year mortality compared with MSSA: HR (95% CI: 1.4 [0.6-3.1]).

CONCLUSIONS

Short-term pediatric mortality after SA bacteremia is low. HA-SA bacteremia has an increased long-term risk for mortality, particularly in children with chronic diseases. Our data suggest mortality was not increased for MRSA compared with MSSA bacteremia. The very low rate of CA-MRSA bacteremia justifies the current practice not to include glycopeptides in the empiric treatment of CA bacteremia in Israel.

[Update on outbreaks reported from neonatal intensive care units (2010-203): Staphylococcus aureus]

In terms of the unique risk profile of the patients and the morbidity associated with S. aureus infections in this vulnerable patient population, the literature on outbreaks of S. aureus (including MRSA) in neonatal intensive care units (NICUs) needs to be analyzed separately from reports derived from other intensive care units. With the objective of updating important information for those involved in outbreak management and fostering preventive efforts, this article summarizes the results of a systematic literature analysis, referring to an earlier publication by Gastmeier et al. It focuses on NICU outbreaks caused by S. aureus (including MRSA) and on controlling them.

MRSA colonization and risk of infection in the neonatal and pediatric ICU: a meta-analysis

BACKGROUND AND OBJECTIVE

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of morbidity and mortality in NICUs and PICUs. Our objective was to assess the burden of MRSA colonization on admission, study the time trends, and examine the significance of MRSA colonization in this population.

METHODS

PubMed and Embase databases were consulted. Studies that reported prevalence of MRSA colonization on ICU admission were selected. Two authors independently extracted data on MRSA colonization and infection.

RESULTS

We identified 18 suitable articles and found an overall prevalence of MRSA colonization of 1.9% (95% confidence interval [CI] 1.3%-2.6%) on admission to the NICU or PICU, with a stable trend over the past 12 years. Interestingly, 5.8% (95% CI 1.9%-11.4%) of outborn neonates were colonized with MRSA on admission to NICU, compared with just 0.2% (95% CI 0.0%-0.9%) of inborn neonates (P = .01). The pooled acquisition rate of MRSA colonization was 4.1% (95% CI 1.2%-8.6%) during the NICU and PICU stay and was as high as 6.1% (95% CI 2.8%-10.6%) when the NICU population was studied alone. There was a relative risk of 24.2 (95% CI 8.9-66.0) for colonized patients to develop a MRSA infection during hospitalization.

CONCLUSIONS

In the NICU and PICU, there are carriers of MRSA on admission, and MRSA colonization in the NICU is almost exclusively associated with outborn neonates. Importantly, despite infection control measures, the acquisition rate is high, and patients colonized with MRSA on admission are more likely to suffer a MRSA infection during hospitalization.

Major characteristics of Staphylococcus aureus colonizing Jordanian infants

BACKGROUND

Colonization of infants with methicillin-resistant Staphylococcus aureus (MRSA) carries specific toxin genes. In particular, Panton-Valentine leukocidin (PVL) are a risk factor for subsequent infection during hospitalization. This prospective study investigated important epidemiological characteristics of Staphylococcus aureus colonizing the nares and intestines of Jordanian infants.

METHODS

A total of 860 nasal and stool specimens were obtained from each of the 430 infants admitted to the neonatal intensive care unit or referred to outpatient clinics of Jordan University Hospital. All specimens were cultured to recover S. aureus, all isolates were tested for antimicrobial susceptibility and the MRSA strains for presence of specific toxin genes and SCCmec using polymerase chain reaction.

RESULTS

Eighty of the 430 (18.6%) infants were colonized with S. aureus, of these, 27 (6.3%) harbored the organism in both the nose and intestine. The frequency of S. aureus nasal and intestinal carriage in outpatient infants compared to inpatients admitted to the neonatal intensive care unit was significantly higher (27.3% vs 2.8%) and (17.1% vs 2.3%), respectively. MRSA accounted for 57/107 (53.3%) of all isolates, and of these 16/57 (28%) were PVL-positive and carried SCCmec type IV, except one, which was type III. All nasal and intestinal MRSA carried at least one toxin gene (tst, eta, seb), but few carried two toxin genes.

CONCLUSION

This study demonstrates that S. aureus strains are more frequently colonizing Jordanian outpatient infants than inpatients and all MRSA strains carried 1-3 clinically important staphylococcal toxin genes. Further studies are needed to investigate the role of these toxins in hospitalized infants.

Selective decontamination of the digestive tract in critically ill children: systematic review and meta-analysis

OBJECTIVE

We examined the impact of selective decontamination of the digestive tract on morbidity and mortality in critically ill children.

DATA SOURCES

We searched MEDLINE, EMBASE, the Cochrane Register of Controlled Trials, and previous meta-analyses.

STUDY SELECTION

We included all randomized controlled trials comparing administration of enteral antimicrobials in selective decontamination of the digestive tract with or without a parenteral component with placebo or standard therapy used in the controls.

DATA EXTRACTION

The primary end point was the number of acquired pneumonias. Secondary end points were number of infections and overall mortality. Odds ratios were pooled with the random effect model.

DATA SYNTHESIS

Four randomized controlled trials including 335 patients were identified. Pneumonia was diagnosed in five of 170 patients (2.9%) for selective decontamination of the digestive tract and 16 of 165 patients (9.7%) for controls (odds ratio 0.31; 95% confidence interval 0.11-0.87; p = .027). Overall mortality for selective decontamination of the digestive tract was 13 of 170 (7.6%) vs. control, 11 of 165 (6.7%) (odds ratio 1.18; 95% confidence interval 0.50-2.76; p = .70). In three studies (n = 109), infection occurred in ten of 54 (18.5%) patients on selective decontamination of the digestive tract and 24 of 55 (43.6%) in the controls (odds ratio 0.34; 95% confidence interval 0.05-2.18; p = .25).

CONCLUSIONS

In the four available pediatric randomized controlled trials, selective decontamination of the digestive tract significantly reduced the number of children who developed pneumonia.

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.

Control of endemic methicillin-resistant Staphylococcus aureus--recent advances and future challenges

Although the exact burden of disease caused by methicillin-resistant Staphylococcus aureus (MRSA) remains largely unknown, most experts agree that MRSA infections are an important clinical and public health problem. Thousands of reports have been published during the last four decades concerning epidemiological and microbiological aspects of MRSA, but uncertainty remains about the best approach to prevent and control this worldwide plague, especially endemic MRSA. Epidemiological methods, e.g., risk scores for targeted screening upon admission, rapid molecular tests and pre-emptive isolation of high-risk patients, new decontamination regimens and restriction of certain antibiotic classes, are all promising approaches that may decrease MRSA cross-transmission; however, further evidence is needed before these strategies can be implemented on a wide scale. Control of community MRSA is an additional challenge for the future, requiring improved surveillance and contact tracing, as well as education and treatment of both infected cases and colonised contacts. This review summarises recent advances and studies that address these issues. Overall, it seems that there is no level of MRSA prevalence for which active control measures are no longer warranted.

Intestinal carriage of Staphylococcus aureus: how does its frequency compare with that of nasal carriage and what is its clinical impact?

The bacterial species Staphylococcus aureus, including its methicillin-resistant variant (MRSA), finds its primary ecological niche in the human nose, but is also able to colonize the intestines and the perineal region. Intestinal carriage has not been widely investigated despite its potential clinical impact. This review summarizes literature on the topic and sketches the current state of affairs from a microbiological and infectious diseases' perspective. Major findings are that the average reported detection rate of intestinal carriage in healthy individuals and patients is 20% for S. aureus and 9% for MRSA, which is approximately half of that for nasal carriage. Nasal carriage seems to predispose to intestinal carriage, but sole intestinal carriage occurs relatively frequently and is observed in 1 out of 3 intestinal carriers, which provides a rationale to include intestinal screening for surveillance or in outbreak settings. Colonization of the intestinal tract with S. aureus at a young age occurs at a high frequency and may affect the host's immune system. The frequency of intestinal carriage is generally underestimated and may significantly contribute to bacterial dissemination and subsequent risk of infections. Whether intestinal rather than nasal S. aureus carriage is a primary predictor for infections is still ill-defined.

Pediatric community-acquired methicillin-resistant Staphylococcus aureus infection and colonization: trends and management

PURPOSE OF REVIEW

The scourge of community-acquired methicillin-resistant Staphylococcus aureus in pediatrics continues unabated. This review provides information on changes in epidemiology, therapeutic considerations, and measures to control the epidemic.

RECENT FINDINGS

The epidemiology and clinical manifestations of methicillin-resistant S. aureus have undergone important changes that pose challenges in recognition, diagnosis, and treatment for the pediatrician. Community-acquired methicillin-resistant S. aureus used to be predominantly associated with localized disease among previously healthy children; however, there are recent reports of more invasive and severe diseases with some fatalities. The antibiotic susceptibility pattern is also changing with some community-acquired methicillin-resistant S. aureus having resistance patterns indistinguishable from that of hospital-acquired methicillin-resistant S. aureus. Thus the choice of antibiotics is becoming even more challenging in pediatrics, with an already-limited armamentarium of antibiotics. The management of common skin diseases such as furunculosis and boils now requires close collaboration between the general pediatrician and the infectious diseases specialist.

SUMMARY

As the burden of community-acquired methicillin-resistant S. aureus disease continues to increase, pediatricians must have a high index of suspicion and must institute appropriate antimicrobial therapy based on community or regional antibiotic susceptibility of community-acquired methicillin-resistant S. aureus. There is an urgent need for effective infection control programs, including active surveillance components, to help curb the epidemic.