Table 2.

Dynamics of detection of SV40 vertical transmission^a

Strain/variant	No. litters positive/No. tested (%)	No. progeny positive/No. testedb (SV40 copies/106 cells)c				Total (%)
		1, 3 days after birth	7 days after birth	14 days after birth	21 days after birth
Baylor-1E	1/2 (50)	0/7 (<5)	1/12 (488)	NDd	ND	1/19 (5)
Baylor-2E	2/5 (40)	4/23 (303)	0/14 (<5)	0/6 (<5)	0/5 (<5)	4/48 (8)
SVCPC	3/4 (75)	ND	5/11 (4,473)	1/10 (908)	0/9 (<5)	6/30 (20)
SVPML-1	2/3 (67)	ND	0/6 (<5)	4/12 (747)	3/12 (582)	7/30 (23)
Total (%):	8/14 (57)	4/30 (303)	6/43 (2,883)	5/28 (799)	3/26 (582)	18/127 (14)
Control	0/6 (0)	0/8 (<5)	0/22 (<5)	0/24 (<5)	0/19 (<5)	0/73 (0)

^aPregnant hamsters were inoculated intraperitoneally with 10⁷ PFU of SV40. From Table 1.

^bOne tissue slice per organ (spleen, kidney, lung, brain) was analyzed for SV40 DNA for each animal.

^cMean viral loads among virus-positive samples.

^dND, not done.