Dec 10, 2007 (CIDRAP News) – Chinese officials said today that analysis of a virus sample from a 24-year-old man who died of H5N1 avian influenza shows no signs of a dangerous mutation, as some news reports said the man and his father, who is hospitalized with an H5N1 infection, both had eaten undercooked chicken.
Mao Qun'an, a spokesman for China's health ministry, told reporters today that though the son's sample showed no evidence of mutation, authorities could not rule out the possibility of human-to-human transmission, Reuters reported.
"The virus is still avian and has not undergone a mutation in its nature," Qun'an said at a press conference. He said the men could have been infected from the same source or separate sources, according to Reuters.
The 24-year-old man, from Nanjing in eastern China's Jiangsu province, died on Nov 27 from an H5N1 infection, according to a previous report from the World Health Organization (WHO). Six days later his father was hospitalized, and on Dec 6 China's national laboratory confirmed the man had an H5N1 infection, according to a WHO statement yesterday. The father is listed as China's 27th H5N1 case-patient.
News of the men's H5N1 infections raised suspicions of human-to-human transmission after media reports and the WHO said the son had no known exposure to sick birds.
However, Ta Kung Pao, a Hong Kong newspaper controlled by the mainland, reported today that both men had eaten undercooked chicken in Nanjing, the capital of Jiangsu, the Reuters report said. The claims came from unnamed sources.
More details on the men's alleged consumption of undercooked chicken were reported today by ProMED-mail, the Internet-based reporting system of the International Society for Infectious Diseases. The ProMED post consists of an English translation of a news article from Singtaonet.com, a newspaper based in Hong Kong.
The ProMED post says the father and his wife took their son and his girlfriend to a restaurant at a temple, where the four ate a dish called "beggar's chicken." According to a 1990 report on beggar's chicken from the New York Times, the chicken is stuffed with herbs, wrapped in lotus leaves, packed with "6 pounds of pond mud," and baked at low heat for several hours.
Two days after eating the chicken, the son became feverish and was hospitalized, the ProMED report said, adding that his father got sick 6 days after eating the meal. Relatives also said the father's refrigerator was full of butchered chicken. The report speculates that the son got sick first because his immune system was weakened because he recently had undergone a series of rabies shots after he was bitten by one of his girlfriend's dogs.
Hans Troedsson, a WHO representative in China, said reports of the men eating undercooked chicken have not been confirmed, Reuters reported today.
The father is recovering after treatment with oseltamivir at the onset of symptoms, Troedsson told the Associated Press (AP) today.
Eighty-two people who had contact with the father and son are being monitored, but none appear to have symptoms, he told the AP.
The two recent cases serve as a reminder that "the virus is circulating in the environment, (and) there is a risk that we will see these isolated cases," Troedsson said.
So far, there is no strong evidence of human-to-human transmission of the H5N1 virus, and the WHO has not received a request to help officials in Nanjing investigate, he told the AP. "We don't see that is an imminent risk that these cases would be the start of a pandemic," he said.
Dec 9 WHO statement
Dec 4 WHO statement
Dec 10 ProMED post on Chinese H5N1 cases
Dec 7 CIDRAP News story "Father of Chinese H5N1 fatality has infection"