Detection of SARS-CoV-2 in Different Types of Clinical Specimens
Detection of SARS-CoV-2 in Different Types of Clinical Specimens. Jefferson T, Heneghan C.,
Published on July 15, 2020
Transmission Dynamics of COVID-19
||Wang W, Xu Y, Gao R, Lu R, Han K, Wu G, et al. Detection of SARS-CoV-2 in Different Types of Clinical Specimens. Detection of SARS-CoV-2 in Different Types of Clinical Specimens. JAMA. 2020 May 12; 323(18): 1843–1844.
||National Key Research and Development Program of China and National Major Project for Control and Prevention of Infectious Disease in China
||Droplets, Orofecal, contact, person to person, bloodborne
In this case series from China, two stool specimens out of 44 positives contained live virus, suggesting that orofecal transmission is possible. Transmission of the virus by respiratory and extra respiratory routes may help explain the rapid spread of disease.
SARs-CoV-2 was detected in all types of specimens except urine.
Sputum and airways specimens were the most frequent with nasal swabs having the lowest PCR cycle threshold indicating the highest copies of viral nucleic material. Of note, there were three blood detections (viraemia) and four SARS-CoV-2 positive fecal specimens with high copy numbers cultured and observed under the microscope. Two out of four had live virions but they came from patients with no diarrhoea.
Twenty patients had two to six specimens collected simultaneously. Viral RNA was detected in single specimens from six patients (respiratory specimens, feces, or blood), while seven patients excreted virus in respiratory tract specimens and in feces (n = 5) or blood (n = 2).
What did they do?
This letter to Editor reports the results of the analysis of 1,070 specimens from pharyngeal swabs (1 to 3 days after admission), blood, sputum, feces, urine, nasal samples, bronchoalveolar lavage fluid and fibre bronchoscope brush biopsy from patients on the basis of clinical indications from three hospitals in the Hubei and Shandong provinces and Beijing, China, from January 1st to February 17th 2020. The specimens came from 205 patients aged mean 44 (5-67 years).
Testing of specimens from multiple sites may improve the sensitivity and reduce false-negative test results.
|Clearly defined setting
||Demographic characteristics described
||Follow-up length was sufficient
||Transmission outcomes assessed
||Main biases are taken into consideration
What else should I consider?
This is a potentially an important study which needs replication
About the authors