This is a interesting question and it took a while to dig up the answer but here it it. According to a U.S. Fish and Wildlife Service (FWS) Notice dated December 21, 2012 hamsters are considered wildlife and are not a domesticated species and therefore import and export are regulated by the FWS. So as a result if the CHO specimens are the actual cells, cell cultures, or cell lines, then a FWS declaration, import/export license, user fees, and clearance are required.
Interestingly, if however, the CHO specimens have been processed to the extent that animal material no longer remains in the specimen, then a FWS declaration and clearance is not required.
In order for a shipment to be exempted from FWS requirements, the trade must submit documents that specifically describe the process that the CHO specimens have gone through. If any statement on the documents indicates that the product such as antibodies or recombinant proteins was extracted from CHO “cells”, “cell cultures”, or “cell lines”, and was purified to remove all cell material, DNA, or animal material, then it is not considered wildlife and FWS clearance is not required.