During the first half of 2003, CA24v was also the etiologic agent responsible for a large outbreak of AHC in several states of Brazil, including Rio de Janeiro (unpub.
Furthermore, comparisons of these sequences were useful to infer phylogenetic relationships among CA24v isolates.
To determine if this amplification product belonged to enterovirus 70 or CA24v, PCR was performed with primers specific to each virus (5), which yielded a 171-bp amplification product, consistent with CA 24v.
For the molecular epidemiologic study, the protease 3C region of CA24v was amplified by PCR with the D1/D2 primer pairs and sequenced as described previously (6).
Nine of the 39 isolates were randomly selected for PCR, performed with the S3/AS3 primer pairs, which are specific to CA24v. All nine isolates yielded the 171-bp amplification product, consistent with CA24v.
The nucleotide sequences of the protease 3C region among the 14 Korean isolates of CA24v were 98.1% to 100% homologous (data not shown).
We also sequenced capsid protein VP1 region of CA24v isolates from two of our patients.
Our study demonstrated that CA24v was the causative agent of the South Korean outbreak of AHC in the summer of 2002.
An outbreak of AHC attributable to CA24v was first recognized in Singapore in 1970; outbreaks have occurred periodically there since (12,13).