Assessment of Environmental Contamination and Environmental Decontamination Practices within an Ebola Holding Unit, Freetown, Sierra Leone

Abstract

Evidence to inform decontamination practices at Ebola holding units (EHUs) and treatment centres is lacking. We conducted an audit of decontamination procedures inside Connaught Hospital EHU in Freetown, Sierra Leone, by assessing environmental swab specimens for evidence of contamination with Ebola virus by RT-PCR. Swabs were collected following discharge of Ebola Virus Disease (EVD) patients before and after routine decontamination. Prior to decontamination, Ebola virus RNA was detected within a limited area at all bedside sites tested, but not at any sites distant to the bedside. Following decontamination, few areas contained detectable Ebola virus RNA. In areas beneath the bed there was evidence of transfer of Ebola virus material during cleaning. Retraining of cleaning staff reduced evidence of environmental contamination after decontamination. Current decontamination procedures appear to be effective in eradicating persistence of viral RNA. This study supports the use of viral swabs to assess Ebola viral contamination within the clinical setting. We recommend that regular refresher training of cleaning staff and audit of environmental contamination become standard practice at all Ebola care facilities during EVD outbreaks.

The Disinfection Characteristics of Ebola Virus Outbreak Variants

“…These authors describe the detection of Ebola vRNA from swabbing performed at 30 and 60 min after cleansing with 0.5% NaOCl, thereby suggesting a nosocomial risk. Although interesting, it is noteworthy that attempts to culture Ebola virus from these swabs was not possible due to lack of suitable facility and containment resources at the treatment units, and nearly one-third of the swab sample-replicates were actually positive for vRNA with Ct values ranging from 32–39 (40 Ct was considered negative)24. Another study which performed vRNA and culturing from swabs showed that despite routine daily cleaning with 0.5% NaOCl, only vRNA, and not culturable virus, was obtained from swabbing blood-contaminated floor areas, six days after an Ebola-infected patient was discharged from an Italian hospital25.…”

New and emerging infectious diseases (Ebola, Middle Eastern respiratory syndrome coronavirus, carbapenem-resistant Enterobacteriaceae, Candida auris): Focus on environmental survival and germicide susceptibility

“…36 Given the high volume of diarrhea and vomiting and the potential for fomite transmission, the frequency of environmental contamination and survival of Ebola virus is of high concern. Several studies have assessed the frequency of contamination within the health care 37,39 or RT-PCR. [37][38][39][40][41][42] Although the frequency of environmental contamination was variable, all studies reported some environmental samples were positive by RT-PCR.…”

Ebola virus RNA detection on fomites in close proximity to confirmed Ebola patients; N’Zerekore, Guinea, 2015

“…However: 1) failing to detect RNA EBOV probably reflects the absence of virus, and 2) detecting RNA EBOV should allow to reinforce preventive measures in identified areas. This statement is supported by Youkee, et al, who showed that sodium hypochlorite disinfection drastically reduces the detection of EBOV RNA in the patients’ environment [12]. Besides, several contaminations occurred in HCWs despite preventions measures.…”