On August 17, a coalition of researchers from Drexel University, the University of Pittsburgh and the National Institute of Health published a research article suggesting that the Ebola virus can survive for at least a week or longer in sterilized waste water. Charles Haas, the department head and director of the environmental engineering program at Drexel was one of the main researchers involved in the discovery.
“My long term research interest is in the assessment and control of human risk from environmental exposure to pathogens, so this fit in well with many other things we’ve done in the past,” he wrote in an email interview. “I started to look at two principal issues — how do we know what the incubation time is, and what happens to patient waste, particularly for the patients coming back to developed countries for treatment.”
Haas, whose specialty includes water treatment, risk assessment, bioterrorism, environmental modeling and statistics, microbiology, and environmental health began by looking into this research by studying the guidelines on viral decontamination set by the World Health Organization and the Center for Disease Control and Prevention. He did this along with colleagues at the University of Pittsburgh. These guidelines state that patient toilet waste could be directly released into the sewage which contradicted what Haas and his colleagues knew about viral infection prevention.
Ebola, a virus currently seen in prevalence in areas of West Africa, dominated the headlines earlier this year when an outbreak reached emergency levels in the region, taking the lives of thousands of people. With some infections reaching all the way to Europe and the United States, infection prevention continues to be a serious issue for medical personnel in West Africa and the States. The virus is known to be passed on from contact of bodily fluids such as blood, saliva, waste, semen and vomit.
After this, the team read into literature about Ebola and its related viruses about its survivability in the environment. They saw no reason in which the guidelines would be effective in eliminating Ebola from the wastewater in the method they said, which would not have worked on many viruses in general. “We were then able to obtain funding from the National Science Foundation and the Water Environment Research Foundation,” Haas wrote. “The NSF work, which Pitt is leading without collaboration, focuses on experimental studies of viruses that could be indicators for Ebola survival in wastewater; we have also been able to collaborate with a group at the National Institutes of Health where they are able to do disinfection studies on Ebola virus.”
He continued, “Our current work is in fact confirming that Ebola can persist in wastewater for as long as a week.”
Haas affirmed that he planned to further conduct experiments on the sensitivity of Ebola to various disinfectants which might be used, such as bleach or detergents. He went on to describe the risks of ebola infected wastewater.
“For the WERF work, which we are leading, we have developed a risk assessment for sewer system workers who are working in the vicinity of the discharge of a hospital wastewater into a sewage collector,” he wrote. “We are finding that the [non-disinfected] patient wastewater may in fact pose a small risk to these workers and further study and data collection are needed to more fully characterize this.”
This study comes some months after another research article Haas published in October 2014 suggesting the quarantine period of 21 days for Ebola was not enough to guarantee that individuals did not contract the disease.
Haas and his team hope this current research will improve the guidelines for disinfection of waste of Ebola-infected patients in the future. His work could influence changes in guidelines for Ebola, and also the guidelines of other dangerous infectious diseases. Haas is currently guiding a master’s student who is writing a thesis in this field and wishes to see the study expand in other directions.