1.   As a precaution in working with the bird flu virus, Dr. Subbarao and others take a drug, rimantidine, to prevent attacks of influenza.

2.   But, Kawaoka asked, why were strains of that virus, unlike most bird viruses, also able to grow so well in people?

3.   Kawaoka explained that bird flu viruses sometimes acquired changes in a protein, hemagglutinin, that the virus needed to burst into cells and infect them.

4.   Meanwhile, a Chinese health official was quoted as saying that no cases of the bird flu virus have so far been found in the southern Guangdong province.

5.   Normally, a bird virus has to go through an intermediate body, or host, such as a pig, to become infectious to humans.

6.   So far, he said, the virus does not look like a bird virus.

7.   That, Dr. Kawaoka said, let the bird virus grow in mice.

8.   The bird virus that killed seven New Yorkers last year has now spread all over the Americas, say U.S. researchers.

9.   The change allows the virus to grow outside the lungs and the intestines, where bird flu viruses are usually contained, and turns the virus lethal for birds.

10.   A government statement said the latest victim died of pneumonia, and that confirmation was not yet available if she had the bird flu virus.