Opinion Editorial
Uncovering Reservoirs of Methicillin-Resistant Staphylococcus aureus Children Contaminating Households or Households Contaminating Children? Aaron M. Milstone, MD, MHS
Methicillin-resistant Staphylococcus aureus (MRSA) emerged in the late 1980s and is a leading cause of skin and soft-tissue infections (SSTIs) in the United States. 1 Unlike hospitalassociated MRSA strains, community-associated MRSA Related article page 1030 strains, commonly designated USA300 by use of pulsed-field gel electrophoresis, initially were found in children without health care exposure. These strains of community-associated MRSA now cause infections in community and hospital settings.2 Recent data from the Centers for Disease Control and Prevention showed that the number of cases of invasive community-associated MRSA infection increased among children between 2005 and 2010.3 Noninvasive MRSA infections far outnumber invasive MRSA infections among children and can lead to a significant economic burden. Many children and families are plagued with recurrent SSTIs. Practitioners have become facile at draining and managing MRSA abscesses, but challenges and uncertainties remain surrounding how to prevent recurrent SSTIs.4 Because most children with recurrent SSTIs are colonized with MRSA, decolonization is commonly prescribed.5 Decolonization involves treating patients with topical antibiotics (intranasal mupirocin calcium) and topical antiseptics (eg, chlorhexidine gluconate washes or bleach baths). Programs can include treating the affected individual or treating entire households.6 Different decolonization regimens have varying efficacy at eradicating MRSA from the body.7 Recurrent infections, however, are common in up to 50% of children despite decolonization protocols.6 Recently, investigators tried periodic treatments with weekly bleach baths, but infections still recurred frequently.8 A number of possibilities may explain why decolonization strategies fail to prevent recurrent infections. First, a child may harbor a mupirocin-resistant strain that will not respond to therapy. Second, tolerability and compliance with intranasal antibiotic administration for children may be limited. Third, other members of a child’s household or the child’s day care, school, or sports team may be colonized with MRSA and, therefore, may reexpose the child shortly after treatment. Finally, many studies have suggested that children become reexposed to the same virulent MRSA strain from inanimate environmental surfaces or objects, including gym towels, razors, and stuffed animals.9 In this issue of the journal, Fritz and colleagues10 present results from a well-designed cohort study that adds to the literature describing households as reservoirs of MRSA for children with recurrent SSTIs.9,11 They enrolled children with com994
munity-associated MRSA SSTIs and searched for household reservoirs of S aureus and MRSA. In 50 households, swab samples were obtained from 21 high-touch surfaces, and the bacterial isolates were tested for relatedness to strains cultured from participants, household contacts, and even pets. Methicillin-resistant S aureus was recovered from at least 1 surface in 50% of households. It was most frequently recovered from the participant’s bed sheets and pillowcase, television remote control, and bathroom hand towel. The bacteria were also recovered from 12% of dogs. In 40% of households, a strain was found on a surface that matched the isolates obtained from the participant. Of the 50 households, only 1 dog had an MRSA strain related to a child’s strain, implying that dogs might be a less likely reservoir than inanimate surfaces. This study10 is provocative and raises many questions, the most important of which are as follows: How does environmental contamination contribute to the epidemic of recurrent SSTIs? Is the environment the source of exposure or reexposure that increases a child’s risk of infection, or is the environment contaminated by the infected or colonized child? Would household cleaning enhance the effectiveness of decolonization therapy? Have decolonization strategies been limited because people are not thorough enough (eg, they do not clean their television remote controls)? This study10 demonstrates that the household is a reservoir of MRSA, but it does not establish a causal relationship between a contaminated environment and recurrent SSTIs. The role of the environment in human disease has been studied for decades, mostly in relation to noninfectious diseases such as asthma. Now, environmental reservoirs of bacteria are being recognized as important contributors to bacterial spread in hospitals.12 In fact, patients admitted to hospital rooms where the prior occupant had MRSA are more likely to acquire MRSA than are patients admitted to hospital rooms where the prior occupant did not have MRSA.13 As a result, hospitals are focusing on environmental decontamination to prevent MRSA. These measures include standard cleaning but also incorporate novel cleaning technologies, such as UV light, hydrogen peroxide gas, and copper surfaces. Novel technologies have been incorporated because routine cleaning often proves to be inadequate. Fritz and colleagues10 attempted to correlate household cleaning with environmental contamination. They identified a lot of variation in the frequency of cleaning common household surfaces, and most people reported that they did not routinely clean some commonly touched surfaces (telephone, television remote control, and bathroom doorknobs). Overall, no association was found between the frequency of cleaning se-
JAMA Pediatrics November 2014 Volume 168, Number 11
Copyright 2014 American Medical Association. All rights reserved.
Downloaded From: http://archpedi.jamanetwork.com/ by a Nanyang Technological University User on 06/05/2015
jamapediatrics.com
Editorial Opinion
lected environmental surfaces and S aureus contamination of that surface; however, self-reported cleaning may poorly reflect actual cleaning practices in the household. Their study10 did identify some important potential reservoirs of contamination, including bed sheets, television remote controls, and hand towels. To our knowledge, there are no controlled studies that have explored the independent effect of household cleaning on reducing recurrent MRSA colonization or infection. Many studies have recommended environmental cleaning in combination with decolonization, yet recurrent infection rates remain high in these studies.6,8 Anecdotally, most clinicians encourage families to clean their household environment while undergoing decolonization therapy. Considerations for decoloARTICLE INFORMATION Author Affiliations: Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Hospital Epidemiology and Infection Control, Johns Hopkins Hospital, Baltimore, Maryland; Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland. Corresponding Author: Aaron M. Milstone, MD, MHS, Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 N Wolfe St, Rubenstein 3141, Baltimore, MD 21287 ([email protected]). Published Online: September 8, 2014. doi:10.1001/jamapediatrics.2014.1260. Conflict of Interest Disclosures: None reported. REFERENCES 1. Moran GJ, Krishnadasan A, Gorwitz RJ, et al; EMERGEncy ID Net Study Group. Methicillin-resistant S. aureus infections among patients in the emergency department. N Engl J Med. 2006;355(7):666-674. 2. Milstone AM, Goldner BW, Ross T, Shepard JW, Carroll KC, Perl TM. Methicillin-resistant Staphylococcus aureus colonization and risk of subsequent infection in critically ill children: importance of preventing nosocomial
nization of pets have been described elsewhere,9 but no data support routine treatment or removal of pets from households of children with recurrent SSTIs. A prospective controlled study is needed to determine whether a contaminated environment increases the risk of recurrent infections or whether infected children simply contaminate their environment. In the meantime, health care workers should inform families with recurrent MRSA infections that the household environment might be contaminated with MRSA and that thoroughly cleaning the house should not make matters worse. Health care workers should be sure to inform families that up to 50% of children may develop a recurrent infection despite the use of best prevention measures.
methicillin-resistant Staphylococcus aureus transmission. Clin Infect Dis. 2011;53(9):853-859.
alone for prevention of recurrent infections. Clin Infect Dis. 2014;58(5):679-682.
3. Iwamoto M, Mu Y, Lynfield R, et al. Trends in invasive methicillin-resistant Staphylococcus aureus infections. Pediatrics. 2013;132(4):e817-e824.
9. Davis MF, Iverson SA, Baron P, et al. Household transmission of meticillin-resistant Staphylococcus aureus and other staphylococci. Lancet Infect Dis. 2012;12(9):703-716.
4. Singer AJ, Talan DA. Management of skin abscesses in the era of methicillin-resistant Staphylococcus aureus. N Engl J Med. 2014;370(11): 1039-1047. 5. Creech CB, Beekmann SE, Chen Y, Polgreen PM. Variability among pediatric infectious diseases specialists in the treatment and prevention of methicillin-resistant Staphylococcus aureus skin and soft tissue infections. Pediatr Infect Dis J. 2008;27 (3):270-272. 6. Fritz SA, Hogan PG, Hayek G, et al. Household versus individual approaches to eradication of community-associated Staphylococcus aureus in children: a randomized trial. Clin Infect Dis. 2012;54 (6):743-751. 7. Fritz SA, Camins BC, Eisenstein KA, et al. Effectiveness of measures to eradicate Staphylococcus aureus carriage in patients with community-associated skin and soft-tissue infections: a randomized trial. Infect Control Hosp Epidemiol. 2011;32(9):872-880.
10. Fritz SA, Hogan PG, Singh LN, et al. Contamination of environmental surfaces with Staphylococcus aureus in households with children infected with methicillin-resistant S aureus [published online September 8, 2014]. JAMA Pediatr. doi:10.1001/jamapediatrics.2014.1218. 11. Uhlemann AC, Knox J, Miller M, et al. The environment as an unrecognized reservoir for community-associated methicillin resistant Staphylococcus aureus USA300: a case-control study. PLoS One. 2011;6(7):e22407. 12. Weber DJ, Rutala WA. Understanding and preventing transmission of healthcare-associated pathogens due to the contaminated hospital environment. Infect Control Hosp Epidemiol. 2013; 34(5):449-452. 13. Huang SS, Datta R, Platt R. Risk of acquiring antibiotic-resistant bacteria from prior room occupants. Arch Intern Med. 2006;166(18):1945-1951.
8. Kaplan SL, Forbes A, Hammerman WA, et al. Randomized trial of “bleach baths” plus routine hygienic measures vs. routine hygienic measures
Vitamin A Shortage and Risk of Bronchopulmonary Dysplasia Matthew M. Laughon, MD, MPH
Bronchopulmonary dysplasia is the most common serious pulmonary morbidity in premature infants.1 Premature infants with bronchopulmonary dysplasia are at increased risk of death, and survivors have life-long morbidities.1-3 DeRelated article page 1039 spite the increased survival of extremely premature infants, bronchopulmonary dysplasia remains a major morbidity.1,2,4 Approximately 40% of infants born between 22 and 28 weeks’ gestation are diagnosed with jamapediatrics.com
bronchopulmonary dysplasia, defined as requiring oxygen supplementation at 36 weeks’ postmenstrual age, although this varies greatly depending on the site of care.1,3,5 The neonatal community has conducted many trials evaluating treatments to reduce the incidence of bronchopulmonary dysplasia, with little success. The only treatments that have reduced the incidence of bronchopulmonary dysplasia in randomized trials without serious adverse events in premature infants are caffeine and vitamin A. JAMA Pediatrics November 2014 Volume 168, Number 11
Copyright 2014 American Medical Association. All rights reserved.
Downloaded From: http://archpedi.jamanetwork.com/ by a Nanyang Technological University User on 06/05/2015
995
Uncovering Reservoirs of Methicillin-Resistant Staphylococcus aureus Children Contaminating Households or Households Contaminating Children? Aaron M. Milstone, MD, MHS
Methicillin-resistant Staphylococcus aureus (MRSA) emerged in the late 1980s and is a leading cause of skin and soft-tissue infections (SSTIs) in the United States. 1 Unlike hospitalassociated MRSA strains, community-associated MRSA Related article page 1030 strains, commonly designated USA300 by use of pulsed-field gel electrophoresis, initially were found in children without health care exposure. These strains of community-associated MRSA now cause infections in community and hospital settings.2 Recent data from the Centers for Disease Control and Prevention showed that the number of cases of invasive community-associated MRSA infection increased among children between 2005 and 2010.3 Noninvasive MRSA infections far outnumber invasive MRSA infections among children and can lead to a significant economic burden. Many children and families are plagued with recurrent SSTIs. Practitioners have become facile at draining and managing MRSA abscesses, but challenges and uncertainties remain surrounding how to prevent recurrent SSTIs.4 Because most children with recurrent SSTIs are colonized with MRSA, decolonization is commonly prescribed.5 Decolonization involves treating patients with topical antibiotics (intranasal mupirocin calcium) and topical antiseptics (eg, chlorhexidine gluconate washes or bleach baths). Programs can include treating the affected individual or treating entire households.6 Different decolonization regimens have varying efficacy at eradicating MRSA from the body.7 Recurrent infections, however, are common in up to 50% of children despite decolonization protocols.6 Recently, investigators tried periodic treatments with weekly bleach baths, but infections still recurred frequently.8 A number of possibilities may explain why decolonization strategies fail to prevent recurrent infections. First, a child may harbor a mupirocin-resistant strain that will not respond to therapy. Second, tolerability and compliance with intranasal antibiotic administration for children may be limited. Third, other members of a child’s household or the child’s day care, school, or sports team may be colonized with MRSA and, therefore, may reexpose the child shortly after treatment. Finally, many studies have suggested that children become reexposed to the same virulent MRSA strain from inanimate environmental surfaces or objects, including gym towels, razors, and stuffed animals.9 In this issue of the journal, Fritz and colleagues10 present results from a well-designed cohort study that adds to the literature describing households as reservoirs of MRSA for children with recurrent SSTIs.9,11 They enrolled children with com994
munity-associated MRSA SSTIs and searched for household reservoirs of S aureus and MRSA. In 50 households, swab samples were obtained from 21 high-touch surfaces, and the bacterial isolates were tested for relatedness to strains cultured from participants, household contacts, and even pets. Methicillin-resistant S aureus was recovered from at least 1 surface in 50% of households. It was most frequently recovered from the participant’s bed sheets and pillowcase, television remote control, and bathroom hand towel. The bacteria were also recovered from 12% of dogs. In 40% of households, a strain was found on a surface that matched the isolates obtained from the participant. Of the 50 households, only 1 dog had an MRSA strain related to a child’s strain, implying that dogs might be a less likely reservoir than inanimate surfaces. This study10 is provocative and raises many questions, the most important of which are as follows: How does environmental contamination contribute to the epidemic of recurrent SSTIs? Is the environment the source of exposure or reexposure that increases a child’s risk of infection, or is the environment contaminated by the infected or colonized child? Would household cleaning enhance the effectiveness of decolonization therapy? Have decolonization strategies been limited because people are not thorough enough (eg, they do not clean their television remote controls)? This study10 demonstrates that the household is a reservoir of MRSA, but it does not establish a causal relationship between a contaminated environment and recurrent SSTIs. The role of the environment in human disease has been studied for decades, mostly in relation to noninfectious diseases such as asthma. Now, environmental reservoirs of bacteria are being recognized as important contributors to bacterial spread in hospitals.12 In fact, patients admitted to hospital rooms where the prior occupant had MRSA are more likely to acquire MRSA than are patients admitted to hospital rooms where the prior occupant did not have MRSA.13 As a result, hospitals are focusing on environmental decontamination to prevent MRSA. These measures include standard cleaning but also incorporate novel cleaning technologies, such as UV light, hydrogen peroxide gas, and copper surfaces. Novel technologies have been incorporated because routine cleaning often proves to be inadequate. Fritz and colleagues10 attempted to correlate household cleaning with environmental contamination. They identified a lot of variation in the frequency of cleaning common household surfaces, and most people reported that they did not routinely clean some commonly touched surfaces (telephone, television remote control, and bathroom doorknobs). Overall, no association was found between the frequency of cleaning se-
JAMA Pediatrics November 2014 Volume 168, Number 11
Copyright 2014 American Medical Association. All rights reserved.
Downloaded From: http://archpedi.jamanetwork.com/ by a Nanyang Technological University User on 06/05/2015
jamapediatrics.com
Editorial Opinion
lected environmental surfaces and S aureus contamination of that surface; however, self-reported cleaning may poorly reflect actual cleaning practices in the household. Their study10 did identify some important potential reservoirs of contamination, including bed sheets, television remote controls, and hand towels. To our knowledge, there are no controlled studies that have explored the independent effect of household cleaning on reducing recurrent MRSA colonization or infection. Many studies have recommended environmental cleaning in combination with decolonization, yet recurrent infection rates remain high in these studies.6,8 Anecdotally, most clinicians encourage families to clean their household environment while undergoing decolonization therapy. Considerations for decoloARTICLE INFORMATION Author Affiliations: Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Hospital Epidemiology and Infection Control, Johns Hopkins Hospital, Baltimore, Maryland; Department of Epidemiology, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland. Corresponding Author: Aaron M. Milstone, MD, MHS, Division of Pediatric Infectious Diseases, Department of Pediatrics, Johns Hopkins University School of Medicine, 200 N Wolfe St, Rubenstein 3141, Baltimore, MD 21287 ([email protected]). Published Online: September 8, 2014. doi:10.1001/jamapediatrics.2014.1260. Conflict of Interest Disclosures: None reported. REFERENCES 1. Moran GJ, Krishnadasan A, Gorwitz RJ, et al; EMERGEncy ID Net Study Group. Methicillin-resistant S. aureus infections among patients in the emergency department. N Engl J Med. 2006;355(7):666-674. 2. Milstone AM, Goldner BW, Ross T, Shepard JW, Carroll KC, Perl TM. Methicillin-resistant Staphylococcus aureus colonization and risk of subsequent infection in critically ill children: importance of preventing nosocomial
nization of pets have been described elsewhere,9 but no data support routine treatment or removal of pets from households of children with recurrent SSTIs. A prospective controlled study is needed to determine whether a contaminated environment increases the risk of recurrent infections or whether infected children simply contaminate their environment. In the meantime, health care workers should inform families with recurrent MRSA infections that the household environment might be contaminated with MRSA and that thoroughly cleaning the house should not make matters worse. Health care workers should be sure to inform families that up to 50% of children may develop a recurrent infection despite the use of best prevention measures.
methicillin-resistant Staphylococcus aureus transmission. Clin Infect Dis. 2011;53(9):853-859.
alone for prevention of recurrent infections. Clin Infect Dis. 2014;58(5):679-682.
3. Iwamoto M, Mu Y, Lynfield R, et al. Trends in invasive methicillin-resistant Staphylococcus aureus infections. Pediatrics. 2013;132(4):e817-e824.
9. Davis MF, Iverson SA, Baron P, et al. Household transmission of meticillin-resistant Staphylococcus aureus and other staphylococci. Lancet Infect Dis. 2012;12(9):703-716.
4. Singer AJ, Talan DA. Management of skin abscesses in the era of methicillin-resistant Staphylococcus aureus. N Engl J Med. 2014;370(11): 1039-1047. 5. Creech CB, Beekmann SE, Chen Y, Polgreen PM. Variability among pediatric infectious diseases specialists in the treatment and prevention of methicillin-resistant Staphylococcus aureus skin and soft tissue infections. Pediatr Infect Dis J. 2008;27 (3):270-272. 6. Fritz SA, Hogan PG, Hayek G, et al. Household versus individual approaches to eradication of community-associated Staphylococcus aureus in children: a randomized trial. Clin Infect Dis. 2012;54 (6):743-751. 7. Fritz SA, Camins BC, Eisenstein KA, et al. Effectiveness of measures to eradicate Staphylococcus aureus carriage in patients with community-associated skin and soft-tissue infections: a randomized trial. Infect Control Hosp Epidemiol. 2011;32(9):872-880.
10. Fritz SA, Hogan PG, Singh LN, et al. Contamination of environmental surfaces with Staphylococcus aureus in households with children infected with methicillin-resistant S aureus [published online September 8, 2014]. JAMA Pediatr. doi:10.1001/jamapediatrics.2014.1218. 11. Uhlemann AC, Knox J, Miller M, et al. The environment as an unrecognized reservoir for community-associated methicillin resistant Staphylococcus aureus USA300: a case-control study. PLoS One. 2011;6(7):e22407. 12. Weber DJ, Rutala WA. Understanding and preventing transmission of healthcare-associated pathogens due to the contaminated hospital environment. Infect Control Hosp Epidemiol. 2013; 34(5):449-452. 13. Huang SS, Datta R, Platt R. Risk of acquiring antibiotic-resistant bacteria from prior room occupants. Arch Intern Med. 2006;166(18):1945-1951.
8. Kaplan SL, Forbes A, Hammerman WA, et al. Randomized trial of “bleach baths” plus routine hygienic measures vs. routine hygienic measures
Vitamin A Shortage and Risk of Bronchopulmonary Dysplasia Matthew M. Laughon, MD, MPH
Bronchopulmonary dysplasia is the most common serious pulmonary morbidity in premature infants.1 Premature infants with bronchopulmonary dysplasia are at increased risk of death, and survivors have life-long morbidities.1-3 DeRelated article page 1039 spite the increased survival of extremely premature infants, bronchopulmonary dysplasia remains a major morbidity.1,2,4 Approximately 40% of infants born between 22 and 28 weeks’ gestation are diagnosed with jamapediatrics.com
bronchopulmonary dysplasia, defined as requiring oxygen supplementation at 36 weeks’ postmenstrual age, although this varies greatly depending on the site of care.1,3,5 The neonatal community has conducted many trials evaluating treatments to reduce the incidence of bronchopulmonary dysplasia, with little success. The only treatments that have reduced the incidence of bronchopulmonary dysplasia in randomized trials without serious adverse events in premature infants are caffeine and vitamin A. JAMA Pediatrics November 2014 Volume 168, Number 11
Copyright 2014 American Medical Association. All rights reserved.
Downloaded From: http://archpedi.jamanetwork.com/ by a Nanyang Technological University User on 06/05/2015
995
