Shedding of methicillin-resistant Staphylococcus aureus and multidrug-resistant gram-negative bacilli during outpatient appointments and procedures outside hospital rooms

Published:March 09, 2021DOI:


      • Limited information is available on shedding of pathogens outside patient rooms.
      • We examined shedding during appointments outside patient rooms.
      • 38.5% of MRSA-colonized patients shed MRSA during appointments.
      • Presence of wounds with MRSA was a significant risk for environmental shedding.
      • No shedding of multidrug-resistant gram-negative bacilli was detected.


      Limited information is available on the frequency of and risk factors for shedding of health care-associated pathogens in settings outside patient rooms.


      We conducted a cohort study of hospitalized or recently discharged patients with methicillin-resistant Staphylococcus aureus (MRSA) (N = 39) or multidrug-resistant gram-negative bacilli (MDR-GNB) (N = 11) colonization to determine the frequency of environmental shedding during appointments outside hospital rooms or during outpatient clinic visits. Chi-square tests were performed to identify patient-level factors associated with environmental shedding. Spa typing was performed for environmental and nasal MRSA isolates.


      Of 50 patients enrolled, 39 were colonized with MRSA and 11 with MDR-GNB. Shedding during 1 or more appointments occurred more often for patients colonized with MRSA versus MDR-GNB (15 of 39, 38.5% versus 0 of 11, 0%; P = .02). The presence of a wound with a positive culture for MRSA was associated with shedding of MRSA during appointments (11 of 15, 73.3% with shedding versus 4 of 24, 16.7% with no shedding; P = .008). Eighty percent of environmental MRSA isolates were genetically related to concurrent nasal isolates based on spa typing.


      Environmental shedding of MRSA occurs frequently during appointments outside hospital rooms or during outpatient clinic visits. Decontamination of surfaces and strategies that reduce shedding of MRSA could reduce the risk for transmission in these settings.

      Key Words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to American Journal of Infection Control
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Donskey CJ
        Does improving surface cleaning and disinfection reduce health care-associated infections?.
        Am J Infect Control. 2013; 41: S12-S19
        • Alhmidi H
        • Cadnum JL
        • Koganti S
        • et al.
        Shedding of methicillin-resistant Staphylococcus aureus by colonized patients during procedures and patient care activities.
        Infect Control Hosp Epidemiol. 2019; 40: 328-332
        • Alhmidi H
        • Cadnum JL
        • Koganti S
        • et al.
        Shedding of multidrug-resistant gram-negative bacilli by colonized patients during procedures and patient care activities.
        Am J Infect Control. 2020; 48: 1336-1340
        • Roghmann MC
        • Johnson JK
        • Sorkin JD
        • et al.
        Transmission of methicillin-resistant Staphylococcus aureus (MRSA) to healthcare worker gowns and gloves during care of nursing home residents.
        Infect Control Hosp Epidemiol. 2015; 36: 1050-1057
        • Pineles L
        • Morgan DJ
        • Lydecker A
        • et al.
        Transmission of methicillin-resistant Staphylococcus aureus to health care worker gowns and gloves during care of residents in Veterans Affairs nursing homes.
        Am J Infect Control. 2017; 45: 947-953
        • Blanco N
        • Pineles L
        • Lydecker AD
        • et al.
        Transmission of resistant gram-negative bacteria to health care worker gowns and gloves during care of nursing home residents in Veterans Affairs community living centers.
        Antimicrob Agents Chemother. 2017; 61 (e00790-17)
        • Mody L
        • Maheshwari S
        • Galecki A
        • Kauffman CA
        • Bradley SF
        Indwelling device use and antibiotic resistance in nursing homes: identifying a high-risk group.
        J Am Geriatr Soc. 2007; 55: 1921-1926
        • Linder KA
        • Hecker MT
        • Kundrapu S
        • et al.
        Evaluation of patients' skin, environmental surfaces, and urinary catheters as sources for transmission of urinary pathogens.
        Am J Infect Control. 2014; 42: 810-812
        • Donskey CJ
        • Chowdhry TK
        • Hecker MT
        • et al.
        Effect of antibiotic therapy on the density of vancomycin-resistant enterococci in the stool of colonized patients.
        N Engl J Med. 2000; 343: 1925-1932
        • Chang S
        • Sethi AK
        • Eckstein BC
        • Stiefel U
        • Cadnum JL
        • Donskey CJ
        Skin and environmental contamination with methicillin-resistant Staphylococcus aureus among carriers identified clinically versus through active surveillance.
        Clin Infect Dis. 2009; 48: 1423-1428
        • Livorsi DJ
        • Arif S
        • Garry P
        • et al.
        Methicillin-resistant Staphylococcus aureus (MRSA) nasal real-time PCR: a predictive tool for contamination of the hospital environment.
        Infect Control Hosp Epidemiol. 2015; 36: 34-39
        • Hefzy EM
        • Wegdan AA
        • Abdel Wahed WY
        Hospital outpatient clinics as a potential hazard for healthcare associated infections.
        J Infect Public Health. 2016; 9: 88-97
        • Reynolds KA
        • Sexton JD
        • Pivo T
        • Humphrey K
        • Leslie RA
        • Gerba CP
        Microbial transmission in an outpatient clinic and impact of an intervention with an ethanol-based disinfectant.
        Am J Infect Control. 2019; 47: 128-132
        • Smith TL
        • Iwen PC
        • Olson SB
        • Rupp ME
        Environmental contamination with vancomycin-resistant enterococci in an outpatient setting.
        Infect Control Hosp Epidemiol. 1998; 19: 515-518
        • Jury LA
        • Sitzlar B
        • Kundrapu S
        • et al.
        Outpatient healthcare settings and transmission of Clostridium difficile.
        PLoS One. 2013; 8: e70175
        • Gontjes KJ
        • Gibson KE
        • Lansing B
        • Cassone M
        • Mody L
        Contamination of common area and rehabilitation gym environment with multidrug-resistant organisms.
        J Am Geriatr Soc. 2020; 68: 478-485
        • Faria NA
        • Carrico JA
        • Oliveira DC
        • Ramirez M
        • de Lencastre H
        Analysis of typing methods for epidemiological surveillance of both methicillin-resistant and methicillin-susceptible Staphylococcus aureus strains.
        J Clin Microbiol. 2008; 46: 136-144
        • Donskey CJ
        • Deshpande A
        Effect of chlorhexidine bathing in preventing infections and reducing skin burden and environmental contamination: A review of the literature.
        Am J Infect Control. 2016; 44: e17-e21
        • Huang SS
        Chlorhexidine-based decolonization to reduce healthcare-associated infections and multidrug-resistant organisms (MDROs): who, what, where, when, and why?.
        J Hosp Infect. 2019; 103: 235-243
        • Vernon MO
        • Hayden MK
        • Trick WE
        • Hayes RA
        • Blom DW
        • Weinstein RA
        • Chicago Antimicrobial Resistance Project (CARP)
        Chlorhexidine gluconate to cleanse patients in a medical intensive care unit: the effectiveness of source control to reduce the bioburden of vancomycin-resistant enterococci.
        Arch Intern Med. 2006; 166: 306-312
        • Cadnum JL
        • Jencson AL
        • Gestrich SA
        • et al.
        A comparison of the efficacy of multiple ultraviolet light room decontamination devices in a radiology procedure room.
        Infect Control Hosp Epidemiol. 2019; 40: 158-163
        • Kanwar A
        • Cadnum JL
        • Thakur M
        • Jencson AL
        • Donskey CJ
        Contaminated clothing of methicillin-resistant Staphylococcus aureus carriers is a potential source of transmission.
        Am J Infect Control. 2018; 46: 1414-1416