[UPDATE 5/10/13: Although human cases of H7N9 infection continue to be reported in China, the increase in case counts has decreased from the month of April. According to the CDC, there have been 131 confirmed cases of H7N9 with 32 deaths as of May 8th.]

On April 1, 2013, the World Health Organization (WHO) first reported 3 human infections with a new influenza A (H7N9) virus in China.  As of April 21, 2013, the number of bird flu cases has risen to 102, including 20 deaths.

The current avian influenza virus, H7N9, has mainly affected eastern China. Four people have additionally tested positive for the virus. This strain was not detected in humans until last month, and the WHO stated there is still no evidence of human-to-human transmission. This is the first time that this flu subtype has been found in people. Most cases have presented with severe respiratory illness.

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The H7N9 viruses have been detected in poultry in the same area where human infections have occurred. Many of the human cases of H7N9 are reported to have had contact with poultry but some reportedly have not had such contact.

Officials from the WHO, as well as experts from the U.S. and European Centers for Disease Control are continuing to monitor these cases alongside Chinese health authorities.

For more information call (800) CDC-INFO or visit the CDC website.