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Environmental detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from medical equipment in long-term care facilities undergoing COVID-19 outbreaks

      Highlights

      • SARS-CoV-2 RNA was detected on medical equipment in long-term care facilities during COVID-19 outbreaks.
      • Blood pressure cuffs were frequently contaminated with SARS-CoV-2 viral RNA.
      • Enhanced cleaning and disinfection, or single-use disposable medical equipment is recommended in long-term care facilities experiencing a COVID-19 outbreak.
      Environmental sampling was conducted at long-term care facilities to determine the extent of surface contamination with severe acute respiratory syndrome coronavirus 2 virus. Medical equipment used throughout the facility was determined to be contaminated.

      Key Words

      Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreaks in community long-term care facilities have primarily been linked to person-to-person transmission; however, despite implementation of enhanced infection control measures limiting person-to-person transmission potential, many long-term care facilities continue to report new cases and sustained outbreaks.
      • Arons MM
      • Hatfield KM
      • Reddy SC
      • et al.
      Presymptomatic SARS-CoV-2 infections and transmission in a skilled nursing facility.
      Environmental contamination with SARS-CoV-2 virus has been hypothesized to propagate spread; however, the extent to which environmental contamination occurs in long-term care settings has yet to be fully understood.
      • Ong SW
      • Tan YK
      • Chia PY
      • et al.
      Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient.
      ,

      Chin A, Chu J, Perera M, et al. Stability of SARS-CoV-2 in different environmental conditions. Lancet Microbe. 2020;1:e10

      We conducted environmental sampling to assess the extent of surface contamination with SARS-CoV-2 virus within long-term care facilities with declared COVID-19 outbreaks

      Methods

      We assessed surface SARS-CoV-2 contamination at 3 licensed long-term care facilities with declared COVID-19 outbreaks within a Canadian metropolitan city. Each long-term care facility services over 150 residents and provides room and board, management of medical conditions, and assistance with activities of daily living.
      • Sanford AM
      • Orrell M
      • Tolson D
      • et al.
      An international definition for “nursing home”.
      Environmental samples were collected from high-touch surfaces, communal sites, and mobile medical equipment at various sites in each of the 3 facilities. Sampling sites were selected based on the distribution of COVID-19 cases within the facility, areas common to case clusters, and the advice of an infection prevention and control specialist. Patient rooms and patient bathrooms were excluded from sampling, as the presence of SARS-CoV-2 in the personal areas of patients diagnosed with COVID-19 was expected.
      Sample collection was conducted using elements of the protocol developed by the World Health Organization; however, sampling of ventilation inlets, collection of control samples, and repeat sampling were not completed.

      Organization WH. Surface Sampling of Coronavirus Disease (COVID-19): A Practical “How to” Protocol for Health Care and Public Health Professionals. Geneva: World Health Organization; 2020

      Sterile premoistened swabs (Aptima Mulittest Swab Specimen Collection Kit; Hologic Inc., San Diego, CA) were used to sample sites. A sample collection area of 25 cm2 was used for all surfaces. Sampling of larger surfaces was completed by sampling the theorized most frequently touched 25 cm2. Sample collection was completed by 2 senior environmental health officers experienced in environmental sample collection.
      Samples were analyzed at the British Columbia Centre for Disease Control Public Health Laboratory via real-time reverse transcriptase-polymerase chain reaction, targeting the RNA-dependent RNA polymerase and E gene regions of the SARS-CoV-2 virus.
      • Ong SW
      • Tan YK
      • Chia PY
      • et al.
      Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient.
      Cycle time values (CT values) were reported for all samples in which SARS-CoV-2 was detected. CT values ≤38 were reported as positives, CT values ≥38.1-40 were reported as indeterminate, while CT values ≥40.1 were reported as negatives.
      Consent for environmental sampling was obtained through the Director of Care or Facility Operator at each COVID-19 outbreak facility.

      Results

      Overall 89 sites were sampled. Table 1 details the sites sampled at each facility. Sampled sites included 20 (22.5%) sites in staff communal areas, and 60 (67.4%) sites in care provision areas; for example, nursing stations, and related medical equipment. Seven sites (7.9%) in an institutional kitchen were also sampled, as well as 2 sites (2.2%) at a main entrance of a facility.
      Table 1Sites sampled and results
      Facility numberLocationCycle threshold value
      Staff area
      1Female staff washroom stall inner stall door handleNegative
      1Female staff washroom soap dispenser push handleNegative
      1Female staff washroom main door inner door handleNegative
      1Male staff washroom stall inner stall door handleNegative
      1Male staff washroom soap dispenser push handleNegative
      1Male staff washroom main door inner door handleNegative
      1Numeric keypad of door entry from kitchen to staff washroom corridorNegative
      1Numeric keypad of door entry from staff washroom corridor to kitchenNegative
      1Cold water tap handle on water coolerNegative
      1Refrigerator door handle in staff loungeNegative
      1Microwave keypad of microwave in staff loungeNegative
      1Microwave keypad of silver microwave in staff loungeNegative
      1Cold water tap handle of staff water cooler in staff loungeNegative
      1Phone receiver of phone in staff loungeNegative
      21st floor water cooler – cold water tap handleNegative
      21st floor staff microwave keypad on top of fridgeNegative
      21st floor staff microwave keypad on top of tableNegative
      21st floor men's staff washroom/changing room door handleNegative
      21st floor beauty salon outer door handleNegative
      3Staff room microwave keypadNegative
      Care provision areas
      11st floor mobile nutrition cartNegative
      11st floor medication cart handle (right side)Negative
      12nd drawer handle of 1st floor medication cartNegative
      11st floor nursing station photocopier touch screenNegative
      11st floor medication administration record (MAR) binder cover at 1st nursing stationNegative
      1Numeric keypad on 1st floor nursing station portable phoneNegative
      1Pen shaft on 1st floor nursing station staff sign-in tableNegative
      11st floor blue (normal adult size – color: blue) blood pressure cuff bladder on mobile patient vitals cart39.18
      11st floor red (large adult size – color: red) blood pressure cuff bladder on mobile patient vitals cart38.6
      11st floor thermometer probe handle on mobile patient vitals cartNegative
      12nd floor thermometer probe handle on mobile patient vitals cart (cart serves facility COVID-19 case cluster)Negative
      12nd floor glucometer on nursing station medication cart (cart serves facility COVID-19 case cluster)Negative
      12nd floor refrigerator door handle on nursing station insulin bar refrigeratorNegative
      12nd floor nursing station black chair arm rest (right side)Negative
      12nd floor nursing station mouse on 2nd floor nursing station computerNegative
      1Numeric keypad on 2nd floor nursing station portable phoneNegative
      23rd floor medication cart side handleNegative
      23rd floor medication cart pill crusher buttonNegative
      23rd floor medication cart blood pressure machine artery marker/second section of bladderNegative
      23rd floor medication cart blood pressure machine touch fastening strap38.65
      23rd floor nursing station blood pressure machine artery bladderNegative
      23rd floor COVID-19 resident section linen cart handle38.54
      23rd floor COVID-19 resident section interior door handleNegative
      23rd floor nursing station portable telephone keypadNegative
      23rd floor nursing station thermometer trigger and handleNegative
      23rd floor nursing station communication binderNegative
      23rd floor nursing station medication administration record binder (blue binder)Negative
      24th floor medication cart O2 saturation finger probeNegative
      24th floor blood pressure artery /second section of bladderNegative
      24th floor medication cart blood pressure machine “start” buttonNegative
      24th floor nursing station thermometer handle and blue buttonNegative
      24th floor nursing station cordless portable phone numeric keypadNegative
      24th floor nursing station communication binder (black)Negative
      24th floor housekeeping cart handleNegative
      24th floor nursing station medication administration record binderNegative
      24th floor thermometer next to staff washroom (buttons only)Negative
      24th floor laundry cart handleNegative
      24th floor laundry chute handle (beside staff only washroom)Negative
      33rd floor nursing station mobile blood pressure machine cart handleNegative
      33rd floor nursing station thermometer buttonNegative
      33rd floor nursing station blood pressure cuff (artery marker section)37.38
      33rd floor nursing station blood pressure cuff touch fastening strapNegative
      33rd floor nursing station MAR e-tablet (Crystal 1)Negative
      33rd floor nursing station MAR e-tablet (Crystal 2)38.48
      33rd floor laundry cart handles (west side) in COVID-19 resident sectionNegative
      33rd floor sling liftNegative
      33rd floor lift operation buttons in hallwayNegative
      33rd floor north side garbage chute handleNegative
      32nd floor nursing station black phone receiver handleNegative
      32nd floor enhanced cleaning cart handleNegative
      31st floor nursing station cold water cooler leverNegative
      31st floor nursing station reusable goggle legsNegative
      31st floor nursing station digital blood pressure cuff touch screenNegative
      31st floor nursing station wrap sleeveNegative
      38th floor ventilation outflow fanNegative
      38th floor elevator call buttonsNegative
      38th floor hand sanitizer button/handleNegative
      38th floor balcony door interior handleNegative
      38th floor room exterior door handleNegative
      3Main floor cleaning cartNegative
      Main areas
      21st floor main entrance phone numeric keypadNegative
      21st floor main entrance phone receiverNegative
      Institutional kitchen area
      3Grey hot food cart rear handleNegative
      3Grey hot food cart silver door handleNegative
      3Grey rolling food cart front handleNegative
      3Grey rolling food cart for secure COVID-19 area front handleNegative
      3Silver coffee urn operation buttonNegative
      3Kitchen elevator call buttonsNegative
      3Kitchen phone numeric padNegative
      Eighty-four (94.3%) of the 89 sites were negative for both SARS-CoV-2 virus targets. Six (6.7%) sites tested positive or indeterminate for the SARS-CoV-2 virus: 2 sites from each of the 3 facilities. The 6 sites with detected SARS-CoV-2 viral RNA included the bladder of a normal adult size reusable blood pressure cuff (E gene cycle threshold: 39.18) (Image 1) and the bladder of a large adult size reusable blood pressure cuff (38.6) (Image 2) in facility 1 (Table 1); the touch fastening strap of a reusable blood pressure cuff (38.65) (Image 3) and the handle of a mobile linen cart (38.54) (Image 4) in facility 2 (Table 1); the bladder of a reusable blood pressure cuff (37.38) (Image 5) and the touch display of an electronic medication administration record (MAR) tablet (38.48) (Image 6) in facility 3 (Table 1).
      The lowest CT value for a sample with SARS-CoV-2 viral RNA detected was the bladder of a blood pressure cuff in facility 3 (37.38).
      Four (44%) of 9 environmental samples taken from blood pressure cuffs contained detectable levels of SARS-CoV-2 viral RNA.

      Discussion

      Environmental contamination with SARS-CoV-2 virus was detected at each of the 3 COVID-19 outbreak facilities sampled in this study, including surfaces of 5 frequently used medical devices transferred between patient rooms, and 1 high-touch surface used by care staff in the course of providing patient care. The detection of SARS-CoV-2 virus on medical devices, such as blood pressure cuffs, used between residents supports the possibility that environmental contamination may be a route for the spread of COVID-19 disease within health care facilities.
      The consistent detection of viral RNA on blood pressure cuffs was an unexpected finding. However, as respiratory etiquette recommends individuals cough or sneeze into their antecubital fossa, it is possible that symptomatic COVID-19 patients may expel SARS-CoV-2 virus on their upper arm with subsequent transmission to a blood pressure cuff. This finding may also relate to the frequency of use of these devices in the facilities, as well as insufficient infection control practices related to their cleaning, disinfection, use, and storage.
      Standard environmental infection control practices recommend cleaning and disinfection of noncritical medical equipment with a low-to-intermediate level disinfectant
      Centers for Disease Control and Prevention
      Guidelines for environmental infection control in health-care facilities: recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC).
      ; however, standard practice may not suffice, especially if equipment is frequently used within a facility allowing for virus accumulation on equipment. Frequently used devices should be cleaned and disinfected on a per-use basis. Single-use, disposable options for equipment, such as blood pressure cuffs, may also be considered.
      This study contains limitations. The swabs used were not validated for environmental sampling, and the sensitivity of their use for the novel virus SARS-CoV-2 is not known. Additionally, all samples with viral RNA detected recorded a CT value greater than 24, a level at which the detected virus may not be infectious in the context of a human nasopharyngeal sample infecting Vero cell lines.

      Bullard J, Dust K, Funk D, et al. Predicting infectious SARS-CoV-2 from diagnostic samples [e-pub ahead of print]. Clin Infect Dis. https://doi.org/10.1093/cid/ciaa638. Accessed August 3, 2020

      However, although the cycle threshold values for these 6 samples were above an observed threshold for SARS-CoV-2 Vero cell infectivity, infectious levels of the virus may have been present before an environmental sample was taken.
      Future studies focusing on environmental contamination with SARS-CoV-2 are required to confirm these results and explore other mechanisms of environmental transmission in the long-term care environment. Given the ubiquity of blood pressure cuffs throughout acute and community health care settings, further research should also explore their role as fomites for SARS-CoV-2 transmission.

      Conclusions

      The findings suggest medical equipment is a potential environmental route for transmission of SARS-CoV-2 virus in long-term care facilities. As such, enhanced environmental cleaning for all medical equipment or prohibiting communal use is recommended.

      Appendix. SUPPLEMENTARY MATERIALS

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        Presymptomatic SARS-CoV-2 infections and transmission in a skilled nursing facility.
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        • Ong SW
        • Tan YK
        • Chia PY
        • et al.
        Air, surface environmental, and personal protective equipment contamination by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from a symptomatic patient.
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