MRSA Infection

Eradication of carriage with methicillin-resistant Staphylococcus aureus: effectiveness of a national guideline

Eradication of carriage with methicillin-resistant Staphylococcus aureus: effectiveness of a national guideline.

Background We evaluated the effectiveness of eradication of methicillin-resistant Staphylococcus aureus (MRSA) carriage in the Netherlands after the introduction of a guideline in 2006. The guideline distinguishes complicated (defined as the presence of MRSA infection, skin lesions, foreign-body material, mupirocin resistance and/or exclusive extranasal carriage) and uncomplicated carriage (not meeting criteria for complicated carriage). Mupirocin nasal ointment and chlorhexidine soap solution are recommended for uncomplicated carriers and the same treatment in combination with two oral antibiotics for complicated carriage. Methods A prospective cohort study was performed in 18 Dutch centres from 1 October 2006 until 1 October 2008. Results Six hundred and thirteen MRSA carriers underwent one or more decolonization treatments during the study period, mostly after hospital discharge. Decolonization was achieved in 367 (60%) patients with one eradication attempt and ultimately 493 (80%) patients were decolonized, with a median time until decolonization of 10 days (interquartile range 7–43 days). Three hundred and twenty-seven (62%) carriers were treated according to the guideline, which was associated with an absolute increase in treatment success of 20% [from 45% (91/203) to 65% (214/327)]. Conclusions Sixty percent of MRSA carriers were successfully decolonized after the first eradication attempt and 62% were treated according to the guideline, which was associated with an increased treatment success.

Nosing around for staphylococci

Controversies in Hospital Infection Prevention: Nosing around for staphylococci.

When we tested these MSSA isolates using the newer GeneXpert MRSA/SA Nasal Assay (the “Nasal Complete” assay), they were correctly identified as S. aureus but not MRSA (this new assay has primers for the mecA gene). Even the “Nasal Complete” assay is susceptible to false positives, though, from the simultaneous presence of an MSSA and a methicillin-resistant coagulase-negative staphylococcus (MR-CoNS) in the same nose (the prevalence of MR-CoNS + MSSA co-colonization was 3.4% in one study). Indeed, the package insert describes a PPV of about 75% for the Nasal Complete—for MRSA, the 25% “false positives” divide equally between those for which culture was negative (which might reflect increased sensitivity of PCR) and those for which the culture grew only MSSA (which may reflect MR-CoNS/MSSA co-colonization). Who knew the nares would be such a vexing place for those who design and market PCR tests?

Self infection in wounds - clinical evidence?

Determination of Staphylococcus aureus carriage in hemodialysis and peritoneal dialysis patients and evaluation of the clonal relationship between carriage and clinical isolates.

Screening cultures yielded 8 (26.6%) isolates from the hemodialysis patients, 9 (22.5%) from the peritoneal dialysis patients, 4 (30.7%) from the staff, and 8 (20%) from the controls. All of the isolates were methicillin-susceptible except one from a hemodialysis patient. There was no significant difference in carriage rate among the study groups. A history of hospital admission in the previous 6 months and a history of infection was associated with an increased carriage rate. A total of 23 genotypes were established for the 28 isolates, demonstrating high clonal heterogenecity. Six clinical isolates from 4 hemodialysis patients and 4 clinical isolates from two peritoneal dialysis patients were molecularly evaluated to compare isolates obtained from infection with carriage isolates of the same patients. All but one of these clinical isolates were “indistinguishable/closely related” to the isolates obtained from the same patients as carriage isolates. Conclusion Opur data show a clear association between S aureus carriage and S aureus infection. Determining the S aureus carriage state of patients undergoing dialysis can help guide infection prevention measures and treatment strategies.

New Nasal MRSA Drug In Development

Successful Proof of Concept for topical antimicrobial drug LytixarTM (LTX-109): Completion of two Phase I/IIa clinical studies | Gamut News.

The Norwegian pharmaceutical company Lytix Biopharma today announces the successful completion of two Phase I/IIa studies with the topical antimicrobial drug LytixarTM (LTX-109) – one for nasal decolonisation of MRSA / MSSA (methicillin-resistant and methicillin-sensitive Staphylococcus aureus) bacteria and one for treatment of Gram+ skin infections.

Staph aureus nasal carriage among hemodialysis outpatients

Prevalence, persistence, and microbiology of Staphylococcus aureus nasal carriage among hemodialysis outpatients at a major New York Hospital.

Only 23/145 (15.9%) dialysis patients were persistently colonized, and only HIV-positive status was associated with persistence (P = 0.05). Prior hospitalization was the only risk factor for methicillin-resistant S. aureus carriage (OR 2.5, P = 0.03). In isolates from patients with ≤42 days of vancomycin exposure, vancomycin minimum bactericidal concentrations (MBCs) increased with duration of exposure. Among dialysis patients, S. aureus colonization was limited and transient; only HIV status was associated with persistence. Nevertheless, duration of vancomycin exposure was associated with increasing vancomycin MBCs. Vancomycin exposure in S. aureus carriers may be involved in increasing resistance.

MRSA colonisation and subsequent risk of infection

MRSA colonisation and subsequent risk of infection... [J Bone Joint Surg Br. 2011] - PubMed result.

The objective of this study was to determine the effectiveness of screening and successful treatment of methicillin-resistant Staphylococcus aureus (MRSA) colonisation in elective orthopaedic patients on the subsequent risk of developing a surgical site infection (SSI) with MRSA. We screened 5933 elective orthopaedic in-patients for MRSA at pre-operative assessment. Of these, 108 (1.8%) were colonised with MRSA and 90 subsequently underwent surgery. Despite effective eradication therapy, six of these (6.7%) had an SSI within one year of surgery. Among these infections, deep sepsis occurred in four cases (4.4%) and superficial infection in two (2.2%). The responsible organism in four of the six cases was MRSA. Further analysis showed that patients undergoing surgery for joint replacement of the lower limb were at significantly increased risk of an SSI if previously colonised with MRSA. We conclude that previously MRSA-colonised patients undergoing elective surgery are at an increased risk of an SSI compared with other elective patients, and that this risk is significant for those undergoing joint replacement of the lower limb. Furthermore, when an infection occurs, it is likely to be due to MRSA.

Prevalence of PVL-Containing MRSA Isolates Among Hospital Staff Nasal Carriers

Prevalence of PVL-Containing MRSA Isolates Among Hospital Staff Nasal Carriers.

Methods: Collectively, 270 nasal swabs were taken from the personnel of 5 university hospitals in Tehran, Iran. Then polymerase chain reaction (PCR) was used to detect the PVL gene. Results: Among the samples taken, 72 (27%) S. aureus isolates were approved. Among the total isolates, there were 23 MRSA (32%) and 14 (19%) PVL gene-containing cases. Conclusion: This study determined that a prevalence of strains exists among hospital staff members who are continuously in direct contact with patients. This may propose the significance of detecting the carriers and decolonizing them to reduce transmission of S. aureus in the hospital.

MRSA Often Hides in Places Other Than the Nose

MRSA Often Hides in Places Other Than the Nose.

f you think stuffing some mupirocin ointment up the nose of a methicillin-resistant Staphylococcus aureus carrier constitutes an adequate attempt at decolonization, think again. MRSA likes to hide in other moist places besides the anterior nares, especially the throat, perineum, armpits, and under pendulous breasts. To determine if a patient with recurrent MRSA abscesses or other skin infections is truly a carrier and thus a candidate for decolonization, it's best to obtain cultures from all these sites, Dr. Theodore Rosen asserted at SDEF Hawaii Dermatology Seminar.

Decolonization a second infection strategy for MRSA infection suggest new guidelines

MRSA infections not limited to hospitals - The Clinical Advisor.

From the new CDC guidlines

# Incision and drainage are recommended as primary treatment for most cutaneous abscesses and boils. # Oral antibiotic options are rated as equivalent. The chice may depend on such factors as patient allergies and cost. # Decolonization is a second-line treatment to be considered when infection has recurred. # Invasive MRSA infection almost always requires hospitalization and treatment with IV antibiotics.

The key above is the suggestion that decolonization be a second infection strategy

Does Multiple MRSA Carriage Sites Increase the Risk of Infection

Dr. Frank Bures: MRSA: The noses have it.

A new study from Rhode Island Hospital, in the Journal of Clinical Microbiology, cultured nose, armpits, between legs, called the perineum (pair-ih-neeyum) and groins. They quantified the number of bacteria from each area. Noses won by much more than a nose. The numbers also showed in this patient group that people with high levels of nasal MRSA were more liable to have positive cultures in other areas. The concept is that, if a person turns up with a MRSA infection, especially in skin and soft tissues, did it perhaps come from a skin source from the patient? Having MRSA on you does NOT guarantee you will get infected, but we think it presents the opportunity. And maybe it is greater if you carry more bugs. Maybe, but not for sure. The question becomes far more likely if someone keeps getting infections, or if someone else in the living unit proves to be the carrier. That has shown unequivocally with the family dog or cat having Strep in their throats, and the kids recurrently getting sick with Strep. Treat the animal (with antibiotics, not necessarily elimination), and the problem clears. This study provokes the question of higher chance of infection, but doesn't answer it. The lead investigator, Dr. Leonard Mermel, said, "We hope that future studies will assess whether or not a greater number of body sites colonized with MRSA or a greater quantity at those sites impacts the likelihood of future MRSA infections." It is the predominant cause of skin infections presenting to emergency rooms, causes major illness and hospitalization, and accounts for about 18,000 deaths per year in the U.S.

80% are staph carriers at some point in their lives

When microbiologists go bad (or in praise of google alerts) | Infectious Thoughts.

About 1 in 5 people permanently carry S. aureus in their noses or on their skin while another 1 in 5 never do. The rest of us will end up carrying S. aureus at some point. S. aureus is another one of these of a ‘Jack of all trades’ and can cause a wide variety of infections, from minor skin infections to food poisoning to major life-threatening illnesses like pneumonia and toxic shock syndrome. The fact that many strains of S. aureus are resistant to most antibiotics (hence MRSA) makes them very difficult to treat and is the reason why those alcohol hand wash dispensers are ubiquitous in hospitals.

Should cardiac surgery be delayed among MRSA carriers?

Should cardiac surgery be delayed among carriers of methicillin-resistant Staphylococcus aureus to reduce methicillin-resistant Staphylococcus aureus-related morbidity by preoperative decolonisation? -- Healy et al. 39 (1): 68 -- European Journal of Cardio-Thoracic Surgery.

MRSA eradication measures prior to admission were successful in 21 of 22 in group 1 (95.4%). There were no MRSA infections in group 1. However, in group 2 there were 11 patients with an MRSA infection (10%) even though eradication measures were started on confirmation of carriage. In group 3, 19 of the 60 patients had an MRSA infection. The intensive care stay and mortality were significantly greater in groups 2 and 3 than in group 1 or compared with the overall patient population. However, groups 2 and 3 also had a significantly higher risk profile (European System for Cardiac Operative Risk Evaluation (EuroSCORE)). When matched with similar risk patients, patients in groups 2 and 3 had mortality outcomes that were consistent with matched risk patients. Conclusion: Patients who were MRSA carriers were older, more likely to have been on haemodialysis and to have been admitted from another hospital and underwent more complex surgical procedures. Carriage of MRSA was associated with a very high rate of MRSA infection, particularly among patients with diabetes. This suggests that delaying surgery may be warranted in patients expected to require implantation of prosthetic material such as valves, especially with diabetes. However, the survival outcomes for MRSA carriers are determined by their EuroSCORE rather than their MRSA status. This suggests that urgent cardiac surgery should not be delayed in patients with MRSA carriage.

Swimmers shed MRSA

Abstract | Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters.

Results Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA. Conclusions This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly demonstrate that adults and toddlers shed their colonizing organisms into marine waters and therefore can be sources of potentially pathogenic S. aureus and MRSA in recreational marine waters. Additional research is needed to evaluate recreational beaches and marine waters as potential exposure and transmission pathways for MRSA.

Nose Best Place to Screen for MRSA Infection?

Nose Best Place to Screen for MRSA Infection? - Infectious Diseases: Causes, Types, Prevention, Treatment and Facts on MedicineNet.com.

A new study finds that people with high levels of methicillin-resistant staphylococcus aureus (MRSA) bacteria in the nose are more likely to have other areas of the body colonized by MRSA, which can cause potentially fatal infections.  Researchers at Rhode Island Hospital wanted to assess the quantity of MRSA at different locations on the body and the relationship between the quantities of MRSA at different locations. The investigators found that MRSA was more likely to be found in the nose than under the arms, the groin, or the perineum (skin between the rectum and genitals). They also found that people with high levels of MRSA in the nose were more likely to have MRSA in the other three locations. "This study shows us that the quantities of MRSA at different body sites are highly correlated. Also, if screening cultures are to be done for MRSA, it is best to screen the nose and groin to get the highest yield," lead author Dr. Leonard Mermel, medical director of the epidemiology and infection control department, said in a hospital news release.

Universal Decolonization of MRSA patients could halve infections

Combination Strategy Halved Spread of MRSA.

Major Finding: Universal contact precautions plus universal decolonization would prevent an estimated 54% of MRSA colonizations and 51% of MRSA infections in a typical hospital. Data Source: A microsimulation model for a hypothetical cohort of 100,000 adult patients admitted to an ICU.

Where does MRSA hide on your body?

Study sheds light on quantity of MRSA at different body sites.

A new study from Rhode Island Hospital has provided new insights into the quantity of MRSA at different body sites as well as the relationship between the quantities at different sites. They found that culturing the nose was more likely to reveal MRSA than culturing under the arms (axilla), the groin, or perineum (skin between the rectum and genitals). Also, when there was a large quantity of MRSA in the nose of a patient, it was likely that there was also a large quantity of MRSA in their axilla, perineum, or groin as well. "This study shows us that the quantities of MRSA at different body sites are highly correlated. Also, if screening cultures are to be done for MRSA, it is best to screen the nose and groin to get the highest yield," said Leonard Mermel.

Nasal Carriage of MRSA linked to school factors

Abstract | Nasal Carriage and Antimicrobial Susceptibility of Staphylococcus aureus in healthy preschool children in Ujjain, India.

Results Of the 1,562 children from 1-month up-to five years of age included in the study 98 children tested positive for nasal carriage of S. aureus. The prevalence of nasal carriage of S. aureus was 6.3% (95% CI 5.1- 7.5) out of which 16.3% (95% CI 8.9-23.8) were methicillin-resistant S. aureus (MRSA). The factors associated with nasal carriage were "child attending preschool" (OR 4.26, 95% CI 2.25-8.03; P=0.007) or "school" (OR 3.02, 95% CI 1.27-7.18; P<0.001) and "family size more than 10 members" (OR 2.76 95% CI 1.06-7.15; P=0.03). The sensitivity pattern of isolated S. aureus showed resistance to commonly used oral antibiotics while resistance to glycopeptides was not noted. Conclusions We found a relatively low rate of nasal carriage of S. aureus in children below five years when compared to children of older age groups in India. Yet, prevalence of MRSA was relatively high.

MRSA Prone? It might be your blood chemistry?

Vampire Microbe Loves Human Blood | Gizmodo Australia.

Friends, this is Staphylococcus aureus. Staphylococcus aureus, here are some victims. You probably already knew each other. After all, the bacteria – origin of the MRSA superbug – lives in the nasal cavity of one third of all humans. Now scientists know why. They like human blood above all other kinds of animal blood. Scientists have found that the bacteria prefer human haemoglobin, which is responsible of carrying oxygen through vertebrates. These microbes attach to this protein to suck its iron and other nutrients, and it just happens that they bind perfectly and easily with our version of haemoglobin. In fact, they seem to prefer different variants of hemoglobin among humans, which may explain why some people suffer repeated infections and others don’t, according to lead researcher Dr Eric Skaar, from Vanderbilt University Medical Center in Nashville, Tennessee: A big question in staph biology is: why do some people continuously get infected or suffer very serious staph infections, while other people do not? Variations in hemoglobin could contribute.

Being MRSA Positive - Helping Patients Respond

MRSA – global threat and personal disaster: patients' experiences - Andersson - 2010 - International Nursing Review - Wiley Online Library.

Aim:  To ascertain and describe the patients' knowledge, perceptions and experiences of being methicillin-resistant Staphylococcus aureus (MRSA) positive. Background:  Antibiotic resistant bacteria are a serious global threat. MRSA can cause wound infection, pneumonia, septicaemia and mortality. This qualitative study has focused on patients' experiences of living with MRSA. Methods:  Fifteen patients with MRSA-infected wounds were interviewed. All data were transcribed verbatim and analysed according to content analysis. Findings:  Information about the MRSA diagnosis often caused a shock-like reaction. Patients' perception of being MRSA positive was stigmatizing as plague or leprosy; they felt dirty and felt that they were a severe threat to their environment. Fears of infecting someone else and being rejected were commonly expressed. The key findings emerged as a theme: Being exposed to others' shortcomings and being a threat to others' health. Three categories were identified: understanding and emotional reactions, treatment by the healthcare professionals and consequences and expectations. Gaps in both patient and staff knowledge of MRSA led to unnecessary misunderstandings, causing fear, social isolation and suffering. Conclusions:  Living with MRSA can be extremely stressful for the patients. Knowledge and empathy from staff involved in their care is crucial to optimize patients' experiences. Staff education to meet patients' demand for information and prevent contamination is essential.

MRSA Carriage Low in UK Children

ScienceDirect - International Journal of Pediatric Otorhinolaryngology : Prevalence of MRSA in elective day case pediatric ENT surgical patients.

Meticillin-resistant Staphylococcus aureus (MRSA) is a common pathogen implicated in hospital acquired infection. Routine preoperative screening for MRSA is current health policy in England and Wales, although children undergoing elective, routine ENT surgery are excluded from this policy. We prospectively assessed a cohort of children admitted for elective ENT surgery to assess this policy. Methods We examined 348 pre-operative children having routine ENT operations to assess MRSA carriage. Results We found bacteriological evidence of MRSA in only one child of the 348 tested. Conclusions This study confirms the current policy and has implications for other countries.