WHAT DO PROTOCOLS SAY?
CDC (Interim Guidance for Environmental Infection Control in Hospitals for Ebola Virus)
FAQ nº 5. “Is it safe for Ebola patients to use the bathroom?”
“Yes. Sanitary sewers may be used for the safe disposal of patient waste. Additionally, sewage handling processes (e.g., anaerobic digestion, composting, and disinfection) in the United States are designed to inactivate infectious agents.”
WHAT ARE PROTOCOLS BASED ON?
CDC recommendations area based on “Guidelines for Environmental Infection Control in Healthcare Facilities”
On chapter I. Regulated Medical Waste: guidelines say:
“5. Discharging Blood, Fluids to Sanitary Sewers or Septic Tanks”
“No evidence indicates that bloodborne diseases have been transmitted from contact with raw or treated sewage. Many bloodborne pathogens, particularly bloodborne viruses, are not stable in the environment for long periods of time; therefore, the discharge of small quantities of blood and other body fluids to the sanitary sewer is considered a safe method of disposing of these waste materials.The following factors increase the likelihood that bloodborne pathogens will be inactivated in the disposal process: a) dilution of the discharged materials with water; b) inactivation of pathogens resulting from exposure to cleaning chemicals, disinfectants, and other chemicals in raw sewage; and c) effectiveness of sewage treatment in inactivating any residual bloodborne pathogens that reach the treatment facility. Small amounts of blood and other body fluids should not affect the functioning of a municipal sewer system.”
“Although concerns have been raised about the discharge of blood and other body fluids to a septic tank system, no evidence suggests that septic tanks have transmitted bloodborne infections. A properly functioning septic system is adequate for inactivating bloodborne pathogens. System manufacturers’ instructions specify what materials may be discharged to the septic tank without jeopardizing its proper operation”
But note that these recommendations refers to medical waste from normal hospital diseases, it means “endemic diseases” in the same document there is the following chapter:
Part II. Recommendations for Environmental Infection Control in Health-Care Facilities : V. Special Precautions for Wastes Generated During Care of Patients with Rare Diseases
- When discarding items contaminated with blood and body fluids from VHF patients, contain these regulated medical wastes with minimal agitation during handling.
- Manage properly contained wastes from areas providing care to VHF patients in accordance with recommendations for other isolation areas (Regulated Medical Waste: III B).
- Decontaminate bulk blood and body fluids from VHF patients using approved inactivation methods (e.g., autoclaving or chemical treatment) before disposal.
Note that VHF (Virus Hemorragic Fever, i.e. Ébola virus)
So it seems that regulations allow, in general, contaminated body fluids disposal through hospital drainage system but they recommend special procedures when managing “rare diseases”
¿BUT IS THERE ANY ALTERNATIVE SYSTEM TO THE HOSPITAL SEWER NETWORK?
It seems like it, and maybe this paragraph should have been placed at the beginning of this article. Autonomous portable WC with chemical treatment are well known in activities as camping and caravanning as well as street sport events and meetings…, in which WC systems are required but there is no possible connection to the public sewer system. These items are WC of closed circuit vessels with chemical additives inside; they allow enclosing and treating a certain amount of feces and urine. This kind of device, placed inside of an Ebola patient room, provides a total containment, decontamination and control of all body fluids in an economic, safety and effective way. This array doesn’t need any refurbishing works neither special utilities, if anything the definition of a decontamination protocol
In Europe a total cost of 2 million euro has been reported as effective cost for each Ebola patient. Against this big figure the small amount of a few hundred of Euros for an autonomous WC is insignificant compared with the containment level achieved. .
WHAT IS INVOLVED USING THE HOSPITAL SEWER NETWORK?
Recommendation of using hospital sewer network is based on two premises:
-Contaminated waste is diluted into a larger amount of other waste and wáter.
-There are waste treatment plants either inside of the hospital or in the municipality.
However, from the available information about Ebola virus (provided mainly also by CDC) it could be reached the following statements:
-Ebola virus can be found inside on feces, urine, blood and body fluids of a declared Ebola patient.
– Ebola virus is classified as Group 4 (highest risk)
-The worse the patient’s condition the larger the viral load on body fluids.
-Ebola virus could remain active for at least six days inside organic waste.
-The virus is transmitted by direct contact with infected body fluids, direct contact with infected materials or direct contact with contaminated animals (alive or dead)
Hospital sewer network (before connection to the treatment system) is composed by hundreds or thousands meter of concealed pipes, with not easy checking access and uncertain preservation status.
These pipes are concealed on false ceilings, chambers, vertical conduits, basements… in general they are hidden from view but covered just by civil work, plasterboard or gypsum, which provide no resistance or containment against break or leakage.
In case of flooding the waste contained in the sewer network can reach the occupied areas.
Sewer network needs maintenance and repair work, technical personnel working on these tasks could be exposed to the direct contact with contaminated materials.
Septic tanks and waste water treatment plants also need maintenance and reparations works, mainly on elements and devices placed before decontamination stages, therefore potentially contaminated (i.e. transfer and grinding pumps)
And finally there is a high likelihood of rats and rodents inside of the sewer network, which could be in contact with contaminated waste before treatment; these are one of the major vectors spreading infectious diseases in urban environments.
Using a risk assessment methodology to evaluate the potential hazards of disposing human fluids contaminated with Ebola virus through the hospital sewer network, it seems that the use of autonomous WC system inside of the containment patient room provides a safer, reliable and validatable way to manage these kind of waste, in addition these systems don’t require special utilities, personnel or investments
It is noted that Ebola virus is considered Risk Group 4 (highest risk) that means:
“A pathogen that usually causes serious human or animal disease and can be readily transmitted from one individual to another, directly or indirectly. Effective treatment and preventive measures are not usually available.”
Biosafety in Microbiological and Biomedical Laboratories (5th Edition) U.S. Department of Health and Human Services. Public Health Service Centers for Disease Control and Prevention National Institutes of Health