Volume 26, Number 8—August 2020
Synopsis
US CDC Real-Time Reverse Transcription PCR Panel for Detection of Severe Acute Respiratory Syndrome Coronavirus 2
Table 9
Inconclusive test results for human specimens with the US CDC real-time RT-PCR panel for detection of SARS-CoV-2*
Specimen ID | Initial test, Ct |
Retest, Ct |
Days after onset | |||||
---|---|---|---|---|---|---|---|---|
N1 | N2 | N3 | N1 | N2 | N3 | |||
Specimen from suspected cases | ||||||||
NP1 |
Neg |
39.3 |
Neg |
Neg |
Neg |
36.9 |
Unknown† |
|
Serial follow-up specimens from laboratory-confirmed COVID-19 cases | ||||||||
NP1 | 36.1 | 39.8 | Neg | Neg | Neg | 37.5 | 15 | |
NP2 | 39.6 | 39.6 | Neg | 36.9 | 38.5 | Neg | 16 | |
NP3 | 41.6 | Neg | Neg | 37.8 | Neg | 39.4 | 12 | |
NP4 | 38.1 | Neg | Neg | 37.0 | 38.5 | Neg | 14 | |
NP5 | Neg | 37.8 | 36.1 | Neg | 38.3 | 36.8 | 16 | |
NP6 | Neg | 40.1 | Neg | Neg | 37.5 | 37.0 | 22 | |
NP7 | Neg | 38.3 | 36.1 | 37.2 | Neg | Neg | 13 | |
NP8 | 38.3 | Neg | 36.0 | 36.7 | 38.1 | Neg | 22 | |
NP9 | Neg | 39.9 | Neg | Neg | 38.7 | Neg | 25 | |
NP10 | Neg | Neg | 36.4 | Neg | Neg | 37.6 | 11 | |
NP11 | 36.6 | Neg | 36.2 | Neg | 38.0 | Neg | 13 | |
NP12 | 37.5 | 39.2 | Neg | Neg | 38.9 | 36.0 | 15 | |
NP13 | 36.9 | Neg | 39.5 | Neg | 36.9 | 37.0 | 13 | |
NP14 | 36.4 | 40.2 | Neg | 36.2 | Neg | Neg | 17 | |
NP15 | 37.0 | Neg | Neg | Neg | 37.2 | Neg | 18 | |
NP16 | Neg | 39.1 | 35.8 | 38.0 | 37.3 | Neg | 11 | |
NP17 | 35.4 | 37.9 | Neg | Neg | 38.7 | 36.9 | 16 | |
NP18 | Neg | 37.8 | 36.1 | 36.7 | 37.2 | Neg | Unknown‡ | |
NP19 | 35.5 | 39.0 | Neg | 39.8 | Neg | Neg | Unknown‡ | |
OP1 | Neg | 38.0 | Neg | 35.9 | Neg | Neg | 18 | |
OP2 | 36.3 | 38.2 | Neg | 38.4 | Neg | Neg | 20 | |
OP3 | Neg | 39.1 | Neg | Neg | 38.4 | 37.8 | 11 | |
OP4 | Neg | 38.2 | 37.3 | 35.8 | Neg | 36.0 | 10 | |
OP5 | Neg | 37.2 | 36.7 | 37.7 | Neg | Neg | 7 | |
OP6 | Neg | Neg | 36.5 | 38.1 | Neg | Neg | 9 | |
OP7 | Neg | Neg | 38.4 | Neg | Neg | 36.6 | 9 | |
OP8 | 37.2 | 38.2 | Neg | 37.2 | Neg | 36.8 | 11 | |
OP9 | Neg | 37.6 | 38.1 | Neg | Neg | 39.3 | 15 | |
OP10 | 36.6 | 38.0 | Neg | Neg | 39.3 | Neg | 9 | |
OP11 | Neg | Neg | Neg | Neg | Neg | Neg | Unknown‡ | |
OP12 | Neg | 37.8 | Neg | 37.6 | Neg | 37.6 | Unknown‡ | |
Sputum 1 | Neg | 42.9 | 37.3 | Neg | Neg | 38.6 | 10 | |
Sputum 2 | 38.0 | Neg | Neg | 36.1 | 38.2 | Neg | 12 | |
Serum 1 | 39.8 | Neg | Neg | Neg | 39.6 | Neg | 6 | |
Serum 2 | 38.1 | Neg | Neg | Neg | Neg | 35.8 | 16 | |
Stool 1 | Neg | Neg | 38.3 | Neg | 40.1 | Neg | 21 | |
Stool 2 | Neg | 38.8 | Neg | 36.9 | 39.2 | Neg | 13 | |
Stool 3 | 36.0 | Neg | Neg | 37.3 | Neg | Neg | 15 | |
Stool 4 | Neg | 39.9 | Neg | 37.7 | Neg | 35.8 | 9 |
*CDC, Centers for Disease Control and Prevention; Ct, threshold cycle; COVID-19, coronavirus disease; N, nucleocapsid protein gene; neg, negative; NP, nasopharyngeal; OP, oropharyngeal; rRT-PCR, real-time reverse transcription PCR; SARS-CoV-2, severe acute respiratory coronavirus 2.
†Repatriated from Diamond Princess Cruise Ship, Japan.
‡Repatriated from Diamond Princess Cruise Ship and confirmed positive in Japan.