FIG 2.

“Fall-and-rise” pattern of viral RNA levels and infectious titers of EV71 at earlier time points postinoculation in various tissues of EV71-infected NOD/SCID mice. One-week-old NOD/SCID mice were infected i.p. with 10⁸ PFU of EV71 strain F23. On different days postinfection, mice were sacrificed. Viral RNA levels (left) and virus titers (right) in the intestine (A), spleen (B), kidney (C), heart (D), lung (E), muscle (F), brain (G), and spinal cord (H) were determined by quantitative RT-PCR and plaque assays. Fold changes of viral RNA copy numbers were detected by VP1 primers and were normalized by GAPDH primers. The virus titer in each tissue was normalized by the weight (in grams) of dissected tissues. Dashed lines connect the average data points at the different time points (see the text for further discussion). Asterisks indicate the time points of disease onset.