Quantitative Detection and Viral Load Analysis of SARS-CoV-2 in Infected Patients.
Clin Infect Dis
; 71(15): 793-798, 2020 07 28.
Article
in English
| MEDLINE | ID: covidwho-17963
ABSTRACT
BACKGROUND:
Coronavirus disease 2019 (COVID-19) has become a public health emergency. The widely used reverse transcription-polymerase chain reaction (RT-PCR) method has limitations for clinical diagnosis and treatment.METHODS:
A total of 323 samples from 76 COVID-19-confirmed patients were analyzed by droplet digital PCR (ddPCR) and RT-PCR based 2 target genes (ORF1ab and N). Nasal swabs, throat swabs, sputum, blood, and urine were collected. Clinical and imaging data were obtained for clinical staging.RESULTS:
In 95 samples that tested positive by both methods, the cycle threshold (Ct) of RT-PCR was highly correlated with the copy number of ddPCR (ORF1ab gene, R2â =â 0.83; N gene, R2â =â 0.87). Four (4/161) negative and 41 (41/67) single-gene positive samples tested by RT-PCR were positive according to ddPCR with viral loads ranging from 11.1 to 123.2 copies/test. The viral load of respiratory samples was then compared and the average viral load in sputum (17â 429â ±â 6920 copies/test) was found to be significantly higher than in throat swabs (2552â ±â 1965 copies/test, Pâ <â .001) and nasal swabs (651â ±â 501 copies/test, Pâ <â .001). Furthermore, the viral loads in the early and progressive stages were significantly higher than that in the recovery stage (46â 800â ±â 17â 272 vs 1252â ±â 1027, Pâ <â .001) analyzed by sputum samples.CONCLUSIONS:
Quantitative monitoring of viral load in lower respiratory tract samples helps to evaluate disease progression, especially in cases of low viral load.Keywords
Full text:
Available
Collection:
International databases
Database:
MEDLINE
Main subject:
Pneumonia, Viral
/
Coronavirus Infections
/
Betacoronavirus
Type of study:
Diagnostic study
/
Experimental Studies
/
Prognostic study
Topics:
Variants
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Language:
English
Journal:
Clin Infect Dis
Journal subject:
Communicable Diseases
Year:
2020
Document Type:
Article
Affiliation country:
Cid
Similar
MEDLINE
...
LILACS
LIS