Table 2  Tests of known respiratory viruses and bacteria in clinical samples and cell culture preparations for cross-reactivity in 2019 novel coronavirus E and RdRp gene assays (n = 310)
Clinical samples with known viruses  Clinical samplesa  Virus isolatesb
HCoV-HKU1  14  1c
HCoV-OC43  16  2d
HCoV-NL63  14  1e
HCoV-229E  18  2f
MERS-CoV  5  1g
Influenza A(H1N1)pdm09  17  1
Influenza A(H3N2)  16  1
Influenza A (untyped)  11   NA
Influenza A(H5N1)  1  1
Influenza A(H7N9)  0  1
Influenza B (Victoria or Yamagata)  31  1
Rhinovirus/enterovirus  31  NA
Respiratory syncytial virus (A/B)  33  NA
Parainfluenza 1 virus  12  NA
Parainfluenza 2 virus  11  NA
Parainfluenza 3 virus  14  NA
Parainfluenza 4 virus  11  NA
Human metapneumovirus  16  NA
Adenovirus  13  1
Human bocavirus  6  NA
Legionella spp.  3  NA
Mycoplasma spp.  4  NA
Total clinical samples   297  NA
a For samples with multiple viruses detected, the virus with highest concentration is listed, as indicated by real-time PCR Ct value.
b Directly quantified or spiked in human negative-testing sputum.
c 1 × 105 RNA copies/mL, determined by specific real-time RT-PCR. Isolated from human airway epithelial culture.
d 1 × 1010 RNA copies/mL, determined by specific real-time RT-PCR of one isolate. The other isolate was not quantified but spiked in human negative-testing sputum.
e 4 × 109 RNA copies/mL, determined by specific real-time RT-PCR.
f 3 × 109 RNA copies/mL, determined by specific real-time RT-PCR of one isolate. The other isolate was not quantified spiked in human negative-testing sputum.
g 1 × 108 RNA copies/mL, determined by specific real-time RT-PCR.