Environmental contamination with SARS-CoV-2 in COVID-19 hospitals in Wuhan, China, 2020.

Coronavirus disease 2019 (COVID-19) pandemic has caused high number of infections and deaths of healthcare workers globally. Distribution and possible transmission route of SARS-CoV-2 in hospital environment should be clarified. We herein collected 431 environmental (391 surface and 40 air) samples in the intensive care unit (ICU) and general wards (GWs) of three hospitals in Wuhan, China from February 21 to March 4, 2020, and detected SARS-CoV-2 RNA by real-time quantitative PCR. The viral positive rate in the contaminated areas was 17.8% (28/157), whereas there was no virus detected in the clean areas. Higher positive rate (22/59, 37.3%) was found in ICU than that in GWs (3/63, 4.8%). The surfaces of computer keyboards and mouse in the ICU were the most contaminated (8/10, 80.0%), followed by the ground (6/9, 66.7%) and outer glove (2/5, 40.0%). From 17 air samples in the contaminated areas, only one sample collected at a distance of around 30 cm from the patient was positive. Enhanced surface disinfection and hand hygiene effectively decontaminated the virus from the environment. This finding might help understand the transmission route and contamination risk of SARS-CoV-2 and evaluate the effectiveness of infection prevention and control measures in healthcare facilities.

Status of contamination with SARS-CoV-2 in isolation wards of Huoshenshan hospital

OBJECTIVE: To evaluate the status of contamination with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) in isolation wards of Huoshenshan Hospital so as to provide scientific basis for developing reasonable strategies of management of environmental health in isolation wards of COVID-19. METHODS: From Mar 9, 2020 to Mar 29, 2020, the samples were systematically collected from 2 common isolation wards that were randomly selected from Huoshenshan Hospital. The sampling objects included environmental samples, samples from personal protective equipment(PPE) of medical staff and samples from hands of medical staff. The samples were collected by cotton swab wiping method, SARS-CoV-2 nucleic acid testing was performed by real time fluorescence quantitative polymerase chain reaction, and the testing results were colleted and analyzed. RESULTS: A total of 244 samples were collected. SARS-CoV-2 nucleic acid testing showed that 1 sample that was collected from bedrail of a patient was tested positive among 171 environmental samples, with the positive rate 0.58%;all of the samples that were collected from PPE of 49 medical staff were tested negative;1 sample that was collected from the hands of a patient was tested positive among 24 samples that were collected from hands of patients and medical staff, with the positive rate 4.17%. CONCLUSION: It is an effective way to reasonably plan for layout of isolation ward and isolation procedure and rigidly implement the systems of environmental disinfection and hand hygiene so as to reduce the degree of contamination with SARS-CoV-2 in isolation wards, cut off the transmission routes of the virus and reduce the risk of exposure to nosocomial infection, meanwhile, it is necessary to strengthen the personal hygiene management during prevention and control of COVID-19.

Development of spike protein-based fluorescence lateral flow assay for the simultaneous detection of SARS-CoV-2 specific IgM and IgG.

The pandemic outbreak of the 2019 coronavirus disease (COVID-19), which is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is still spreading rapidly and poses a great threat to human health. As such, developing rapid and accurate immunodiagnostic methods for the identification of infected persons is needed. Here, we proposed a simple but sensitive on-site testing method based on spike protein-conjugated quantum dot (QD) nanotag-integrated lateral flow immunoassay (LFA) to simultaneously detect SARS-CoV-2-specific IgM and IgG in human serum. Advanced silica-core@dual QD-shell nanocomposites (SiO2@DQD) with superior luminescence and stability were prepared to serve as fluorescent nanotags in the LFA strip and guarantee high sensitivity and reliability of the assay. The performance of the SiO2@DQD-strip was fully optimized and confirmed by using 10 positive serum samples from COVID-19 patients and 10 negative samples from patients with other respiratory diseases. The practical clinical value of the assay was further evaluated by testing 316 serum samples (114 positive and 202 negative samples). The overall detection sensitivity and specificity reached 97.37% (111/114) and 95.54% (193/202), respectively, indicating the huge potential of our proposed method for the rapid and accurate detection of SARS-CoV-2-infected persons and asymptomatic carriers.

Persistent SARS-COV-2 RNA positivity in a patient for 92 days after disease onset: A case report.

RATIONALE: Recently, patients with COVID-19 who showed persistently positive SARS-CoV-2 nucleic acid test results despite resolved clinical symptoms have attracted a lot of attention. We report the case of a patient with mild symptoms of coronavirus disease (COVID-19), who achieved clinical recovery but showed persistently positive SARS-CoV-2 nucleic acid test results until Day 92 after disease onset. PATIENT CONCERNS: The patient is a 50-year-old man with mild symptoms of coronavirus disease (COVID-19). DIAGNOSES: COVID-19 pneumonia. INTERVENTIONS: The patient was quarantined for 105 days. Of these, inpatient quarantine lasted for 75 days. When the nucleic acid test results were negative for 3 consecutive days, the patient was discharged at Day 75 after disease onset. During this period, multiple samples were collected from the patient's body surface, the surrounding environment, and physical surfaces, but none of these tested positive for SARS-CoV-2. These samples included those from anal swabs, hands, inner surface of mask, cell phone, bed rails, floor around the bed, and toilet bowl surface. However, nucleic acid retest results on Day 80 and Day 92 after disease onset were positive for SARS-CoV-2 nucleic acids. OUTCOMES: The patient continued with quarantine and observation at home. After the test results on Days 101 and 105 after disease onset were negative, quarantine was terminated at last. LESSONS: Per our knowledge, this is the longest known time that a patient has tested positive for SARS-CoV-2 nucleic acids. No symptoms were observed during follow-up. During hospitalization, the SARS-CoV-2 nucleic acid positivity was not observed in samples from the body surface and surrounding environment, and no verified transmission event occurred during the quarantine at home. After undergoing clinical recovery a minority of patients with COVID-19 have shown long-term positive results for the presence of the SARS-CoV-2 nucleic acid. This has provided new understanding and research directions for coronavirus infection. Long-term follow-up and quarantine measures have been employed for such patients. Further studies are required to analyze potential infectivity in such patients and determine whether more effective antiviral drugs or regimens to enable these patients to completely clear viral infection should be researched.