FIG 3 .
The viral load in each month. The viral load in each month was determined using quantitative real-time (RT)-PCR with a sense primer (5-ACDATYTCATCATCACCATA-3) and an antisense primer (5-TGGAATTCCATCGCCCACTGG-3). The viral loads are the mean results of duplicate runs, and the error bars show standard deviations.