One in 204 samples tested at large cancer center was positive for virus

Contamination of environmental surfaces with SARS-CoV-2 at a large, tertiary cancer center was negligible in both inpatient- and outpatient hematology and oncology settings with strict Covid-19 mitigation protocols in a prospective, real-world quality assurance investigation.

The study was conducted to assess the incidence of SARS-CoV-2 viral RNA in high-touch spaces at the cancer center over a two-week period from mid-to-late June 2020.

Among the 130 surfaces examined from two outpatient hematology/oncology clinics and 36 samples from non-Covid-19 inpatient units, all 166 surfaces were negative for SARS-CoV-2 viral RNA.

Just one of 38 samples taken from Covid-19 positive inpatient units showed viral contamination, wrote researcher Andrew M. Evens, DO, of Rutgers Cancer Institute of New Jersey, and colleagues in the journal Cancer.

The findings show that infection control efforts such as telephone screening, visitor restrictions, telehealth, and personal protective equipment are highly effective for limiting environmental surface contamination with SARS-CoV-2 and nosocomial infection, the researchers noted.

“The results of this study are reassuring and should reduce concerns for patients and health care providers about infection transmission from environmental surfaces in outpatient and inpatient oncology spaces when strict mitigation strategies against SARS-CoV-2 transmission are instituted,” they wrote.

They noted that cancer patients are especially vulnerable to developing severe disease and dying from Covid-19 — the reported Covid-19 fatality rate among cancer patients was as high as 26% in one study.

What’s more, the Covid-19 pandemic has contributed to delays in patients seeking cancer screening and medical care for cancer.

“Although Covid-19 is known to be transmitted person to person via respiratory droplets and fecal-oral transmission, contact with environmental surfaces (e.g., plastics, metals, and cardboard), on which SARS-CoV-2 may be viable for up to 72 hours under laboratory conditions, is also a potential vector of infectivity,” Evens and colleagues wrote.

Their study was designed to determine if SARS-CoV-2 contamination is common on high traffic environmental surfaces in a tertiary cancer care center.

Surfaces were tested over a two-week period after patient or staff exposure but before scheduled disinfection services according to the World Health Organization protocols for Covid-19 surface sampling. Samples were analyzed via reverse transcriptase–polymerase chain reaction for the presence of SARS-CoV-2 RNA.

A total of 204 environmental samples were obtained from inpatient and outpatient oncology clinics and infusion suites, and all samples were categorized as either public areas, staff areas, or medical equipment.

Altogether, the positive test rate for SARS-CoV-2 RNA across all surfaces was 0.5% (1 of 204).

“The one positive sample from a Covid-19 unit reinforces the importance of physical separation of patients infected with SARS-CoV-2,” the researchers wrote. “We speculate that the floor may have contained fomites composed of viral RNA. “

In a similar study exploring environmental surface contamination with SARS-CoV-2 conducted in Singapore, researchers concluded that floor spaces were the areas most likely to be contaminated with the virus.

Separate studies from China and Singapore, conducted early in the Covid-19 pandemic, showed significant environmental contamination with SARS-CoV-2 RNA in hospital wards and on commonly touched surfaces in medical facilities.

“Although multiple studies have found SARS-CoV-2 on environmental surfaces, few have attempted to culture the virus from positive samples,” Evens and colleagues wrote.

They noted that there remains uncertainty about whether these positive samples actually contained viable virus and whether respiratory droplets on surfaces represent a significant threat of Covid-19 disease transmission.

“In the context of potentially immunocompromised patients with cancer, it is important to understand the role of environmental contamination to further protect this vulnerable population,” they wrote. “Despite infection control guidelines specific to oncology care, cancer-related encounters have remained below expectant volumes, and this perhaps reflects persistent concerns about acquiring a nosocomial Covid-19 infection.”

The researchers concluded that additional studies are needed “to monitor rates of virus transmission and the environmental factors involved in the propagation of the SARS-CoV-2 infection.”

  1. Contamination of environmental surfaces with SARS-CoV-2 at a large, tertiary cancer center was negligible in both inpatient- and outpatient hematology and oncology settings with strict Covid-19 mitigation protocols.

  2. Just 1 of 204 environmental surfaces tested contained evidence of the SARS-CoV-2, for a positivity rate of 0.5%.

Salynn Boyles, Contributing Writer, BreakingMED™

The researchers disclosed no funding source. Principal researcher Andrew M. Evens reported receiving honoraria for research advisory boards from Seattle Genetics, MorphoSys, Mylteni, Epizyme, Novartis, Karyopharm, Pharmacyclics, and AbbVie.

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