October 15th Outside Nina Pham’s Apartment
One of the more striking images that emerged out of America’s first couple of brushes with the Ebola virus involved Hazmat-suited responders sealing off and then entering – and attempting to decontaminate – spaces where an Ebola infected individual had stayed.
Out of an abundance of caution – and no doubt to reassure a nervous public - common areas at apartment buildings were sprayed down with disinfectants, hand rails in hospital parking lots sanitized, and air carriers took planes out of service for repeated cleanings - which in some cases included removing sections of their carpet and seat covers.
According to the Dallas Morning News (see Cleanup crews try to salvage most of Ebola nurses’ belongings), some of the `extreme cleaning’ measures were taken in the apartments of the nurses who were infected while treating America’s index case included:
Cushions were removed from furniture, linens stripped, carpets and padding ripped out, all surfaces were `triple-wiped’ with industrial strength cleaners, and multiple barrels of `potentially contaminated’ personal effects were removed and incinerated.
While some of this may seem excessive, there isn’t a great deal of data on the environmental persistence of the Ebola virus. The CDC’s Interim Guidance for Environmental Infection Control in Hospitals for Ebola Virus has this to say:
How long does the Ebola virus persist in indoor environments?
Only one laboratory study, which was done under environmental conditions that favor virus persistence, has been reported. This study found that under these ideal conditions Ebola virus could remain active for up to six days.1 In a follow up study, Ebolavirus was found, relative to other enveloped viruses, to be quite sensitive to inactivation by ultraviolet light and drying; yet sub-populations did persist in organic debris.2
In the only study to assess contamination of the patient care environment during an outbreak, conducted in an African hospital under "real world conditions", virus was not detected by either nucleic acid amplification or culture in any of 33 samples collected from sites that were not visibly bloody. Virus was detected on a blood-stained glove and bloody intravenous insertion site by nucleic acid amplification, which may detect non-viable virus, but not by culture for live, infectious virus.3 Based upon these data and what is known regarding the environmental infection control of other enveloped RNA viruses, the expectation is with consistent daily cleaning and disinfection practices in U.S. hospitals that the persistence of Ebola virus in the patient care environment would be short – with 24 hours3 considered a cautious upper limit.
With the likelihood that we will see more Ebola cases in the United States in the coming weeks and months, there is great need for guidance on residential decontamination that provides for the safety of the public, but that doesn’t unnecessarily involve an all out `scorched-earth’ strategy.
Although those with Ebola are very infectious in the latter stages of their illness – early on – before vomiting and diarrhea set in, we’ve seen very little evidence of significant viral shedding.
Using this as a line of demarcation between the types of cleanup and decontamination, yesterday the CDC released interim guidance called:
Effective disinfectant product(s): Use an Environmental Protection Agency (EPA)-registered hospital disinfectant according to manufacturer’s instructions with a label claim against a non-enveloped virus, such as norovirus, rotavirus, adenovirus, or poliovirus. Currently, no EPA-registered disinfectant products will have a statement on the label that specifically says it can kill Ebola virus. However, any EPA-registered disinfectant that is effective against a non-enveloped virus will also be effective against Ebola virus.
One simple way to identify an appropriate product effective against Ebola virus is to use a product included in EPA’s List L: Disinfectants for Use Against the Ebola Virus.
- Level of cleaning and decontamination: Once a person has been confirmed to have Ebola, the way to decontaminate the residence depends on the person’s symptoms at the time they were in the residence:
- Cleaning by residents - If the person with Ebola only had a fever with no gastrointestinal (e.g., diarrhea, vomiting) or hemorrhagic (bleeding) symptoms while he or she was in the residence, the person should not be contaminating their environment. Therefore, remaining members of the residence can clean and launder as normal.
- Cleaning by contract company - If the person with Ebola had a fever AND diarrhea, vomiting, and/or unexplained bleeding, public health and/or assigned authorities may need to contact a contract company who will assess the residence to determine the proper decontamination and disposal procedures. Remaining members of the residence should avoid contaminated rooms and areas until after the completion of the assessment and decontamination.
- Which contract companies can conduct the cleaning?: Companies with experience in cleaning biohazard and crimes scenes. OSHA provides guidance for cleaning and decontaminating in non-healthcare settings. Any contract company conducting such work must comply with the its state’s Ebola policies and with OSHA standards for, among others that may apply, bloodborne pathogens (29 CFR 1910.1030), personal protective equipment (PPE) (29 CFR 1910.132), respiratory protection (29 CFR 1910.134), and hazard communication (29 CFR 1910.1200) (e.g., for chemical hazards). In states that operate their own occupational safety and health
- Transport of waste: Transportation of Ebola-contaminated waste (i.e., materials that cannot be decontaminated and were in contact with the person with Ebola having fever AND diarrhea, vomiting, and/or unexplained bleeding) must be packaged and transported in accordance with regulations on the transportation of Ebola contaminated items provided by the U.S. Department of Transportation (DOT): U.S. DOT Hazardous Materials Regulation for Category A Infectious Substance. If a contract company is handling the waste, requirements in OSHA standards, including Bloodborne Pathogens (29 CFR 1910.1030) may also apply.
Interim guidance is exactly what it says on the tin. Guidance that is constantly subject to review and revision.
As we gain more experience with dealing with the Ebola virus in the developed world, we’ll get a much better idea of the risks – and the most effective countermeasures – involved.