MRSA Persistence Linked With Household Members and Pets Interview with:
Valerie Cluzet, MD
Hospital of the University of Pennsylvania
Division of Infectious Diseases
Philadelphia, PA 19104

MedicalResearch: What is the background for this study? What are the main findings?

Dr. Cluzet: MRSA is a major cause of skin and soft tissue infection (SSTI) in the community and we know that colonization is an important risk factor for subsequent infection. Past studies have calculated duration of colonization based on colonization at hospital admission or focused on populations not representative of the typical community-dwelling patient. We wanted to identify the factors associated with duration of colonization in a typical patient that clinicians would see (i.e. adults and children presenting to ambulatory setting with a MRSA SSTI), so that the findings would be generalizable and relevant to their practice. In addition, there has been an increasing focus on the role of the household in transmission of MRSA, so wanted to specifically examine that in a longitudinal, systematic way.

There are a few major points that emerged from our study.

1) The first is that the duration of colonization after treatment for a methicillin-resistant Staphylococcus aureus (MRSA) skin and soft tissue infection (SSTI) is relatively short, but there is a significant subset of patients (approximately 20%) who will have persistent colonization.

2) We also found that treatment of the MRSA SSTI with clindamycin was associated with shorter duration of colonization, an association we did not see with other MRSA-active agents.

3) Finally, this study highlights the potential role of MRSA colonization among household members as a contributing factor in duration of colonization in patients.

MedicalResearch: What should clinicians and patients take away from your report?

Dr. Cluzet: These findings contribute to the growing knowledge that MRSA colonization among household members, household items and even pets are sources of MRSA transmission and may contribute to inability to clear MRSA colonization, increasing the risk for recurrent infections. A recent study showed that decolonization of the whole household led to fewer recurrent infections in children. The effect of total household decolonization needs to be studied in a broader population including adults as well as children in order to confirm these findings and recommend this strategy more broadly.

Additionally, the reasons for association between treatment with clindamycin and more rapid clearance of colonization remain unclear, but it may argue for preferential use of clindamycin in those diagnosed with MRSA SSTI to shorten the duration of colonization.

MedicalResearch: What recommendations do you have for future research as a result of this study?

Dr. Cluzet: I think the most important contribution of this study is the questions it raises for future research. We should examine the risk factors for recurrent colonization and those for recurrent infection in order to better identify those subjects and to implement strategies to decrease the burden of infection. Similarly, we would like to identify those factors that are associated with persistent colonization (i.e. the 20% of subjects that never cleared colonization), as these are potentially the patients at highest risk of recurrent infections and so we could focus efforts on this subgroup. Also, as I discussed earlier, we need to study the effect of total household decolonization on duration of colonization and recurrent infections in adults and children, as well as the reasons for clindamycin’s association with shorter duration of MRSA colonization and its role in decolonization protocols.


Duration of Colonization and Determinants of Earlier Clearance of Colonization with Methicillin-Resistant Staphylococcus aureus
 Valerie C. Cluzet,et al

Clin Infect Dis. first published online February 3, 2015 doi:10.1093/cid/civ075 Interview with: Valerie Cluzet, MD (2015). MRSA Persistence Linked With Household Members and Pets