[Detection and evaluation of SARS-CoV-2 nucleic acid contamination in corona virus disease 19 ward surroundings and the surface of medical staff's protective equipment].
Level 4 - case-series / case-control
Cross-sectional environmental survey and descriptive staff surveillance
PubMed 33047711 · doi:10.19723/j.issn.1671-167X.2020.05.002
What was done
Between March 11 and March 19, 2020, researchers at a COVID-19 designated hospital in Wuhan, China, evaluated environmental contamination and medical staff infection. Air samples were collected across clean areas, buffer rooms, and contaminated ward areas using a WA-15 bioaerosol concentrator. Sterile premoistened swabs were used to sample high-frequency contact surfaces in contaminated areas and personal protective equipment (PPE) surfaces (outermost gloves, tracheotomy operator positive pressure respiratory hoods, isolation gowns). Viral RNA was measured by real-time quantitative RT-PCR. Healthcare personnel working in the wards were screened during medical observation using oropharyngeal swabs (RT-PCR), serum IgM/IgG antibodies, and chest CT scans.
What was found
SARS-CoV-2 nucleic acid was not detected in any environmental or PPE sample: - 0 of 90 air samples across clean, buffer, and contaminated areas were positive. - 0 of 38 high-frequency contact surface samples were positive. - 0 of 16 PPE surface samples were positive. Among the 137 healthcare workers evaluated, 0 tested positive for viral RNA on oropharyngeal swabs, 0 had detectable serum IgM or IgG antibodies, and 0 exhibited COVID-19 lung presentations on chest CT scans.
Why it matters
The study suggests that rigorous infection control protocols—including high-level PPE, environmental disinfection, patient habit guidance, and hospital ventilation—can prevent detectable environmental contamination and occupational transmission in dedicated COVID-19 wards.
Limits
The study was conducted at a single hospital over a brief 8-day period late in the initial Wuhan outbreak. Sample sizes for specific categories were small (e.g., 16 PPE samples). The abstract does not report patient census, disease severity, ward ventilation rates, or assay detection limits.
Cited by
- supports Air sampling studies in Chinese hospital wards with COVID-19 patients found almost undetectable levels of SARS-CoV-2 in the air, but detected viral material on air conditioning grates and filters.