It's easy to forget, but the first country to report avian cases of H5N1 avian flu during the serious winter 2003 outbreak was not Vietnam or China or Thailand, but modern South Korea. Unlike many of their regional neighbors, who hid or ignored evidence of the disease, the South Koreans were quick to report the outbreak to international health authorities and implement strict control procedures.
That's why South Korea was able to bring its initial outbreak to a relatively quick close—albeit at the cost of nearly 6 million chickens and $1.6 billion—while in much of the rest of Asia, the disease continues to spread today.

But avian flu is hard to eradicate, and this weekend the South Korean government confirmed a new outbreak of H5N1 at a chicken farm about 100 miles outside of Seoul. Just as it did in 2003, South Korea is moving quickly to snuff out the infection, culling 236,000 chickens so far within a 3 mile radius of the initial outbreak.

There have been no reported human infections, and chances are they'll stop the outbreak. H5N1 has yet to permanently establish itself in a country as rich as South Korea. But the infections are an unpleasant reminder of the panicky winter of 2003—and the sobering reality that H5N1 has made a home throughout Asia.

One last note: those who want a concise summary of the evolution of H5N1 and the pandemic threat it poses to the world should check out a commentary published last week in the New England Journal of Medicine. It's written by Robert Webster and Elena Govorkova of St. Jude Children's Research Hospital—two of the foremost names in the field.

—By Bryan Walsh/Tokyo