Health Highlights: Dec. 11, 2008

The first outbreak of H5N1 bird flu on a Hong Kong poultry farm in nearly six years was confirmed by government officials Thursday.

It was announced Tuesday that bird flu was found on a farm near the Chinese border and 90,000 chickens were scheduled for slaughter by the end of the week. Initial tests identified an H5 virus and the new test results confirmed that it's the deadly H5N1 virus, Agence France Presse reported.

The virus has not been found on any other farms in the area.

The World Health Organization is monitoring the situation, said Peter Cordingley, a spokesman for the WHO's Western Pacific regional office. He told AFP the outbreak isn't a surprise because the virus is versatile and tends to be more active in winter.

Hong Kong officials said the H5N1 virus has "changed slightly" and have told scientists to investigate whether the vaccine used since 2003 to protect chickens against bird flu is still effective.

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Men's Genes Influence Offsprings' Gender

A man's genes may play a major role in whether he has sons or daughters, according to U.K. researchers who examined 927 family trees that included information on 556,387 people from Europe and North America.

The study found that men were more likely to have sons if they had more brothers and more likely to have daughters if they had more sisters, BBC News reported. The same link between sibling gender and offspring gender wasn't seen in women.

The results provide strong evidence of a genetic component affecting the relative numbers of "X" and "Y" sperm produced by men, said study author Dr. Corry Gellatly, who added that this type of male-directed gender selection balances out the proportion of men and women in the population.

"If there are too many males in the population, for example, females will more easily find a mate, so men who have more daughters will pass on more of their genes, causing more females to be born in later generations," Gellatly said, BBC News reported.

The study was published in the journal Evolutionary Biology.