Table 2.

Comparison of Two Nested RT-PCR Results With Corresponding Viral Loads of SARS-CoV in the NPS Among HCWs

Groups of HCWs	Subjects, No.	First Nested RT-PCR	Second Nested RT-PCR	Viral RNA, Copies per Milliliter, mean ± SD	Contact History With SARS
Negative nested RT-PCR	203	Negative	Negative	0	Yes (n = 190); no (n = 13)
Positive nested RT-PCR
Asymptomatic	19	Negative	Positive	312 ± 204	Yes
Mildly symptomatic	6	Negative	Positive	386 ± 203	Yes
SARS*	2	Positive	Positive	16,900 ± 7,920	Yes

^*p < 0.01 compared to mildly symptomatic and asymptomatic HCWs.