H5N1 death in Laos confirmed; Chinese reject research report

Mar 8, 2007 (CIDRAP News) – The World Health Organization (WHO) has confirmed the first fatal case of H5N1 avian influenza in Laos, involving a 15-year-old girl, while Chinese officials have denied new research claims that several strains of the virus originated in Guangdong province.

The Laotian girl died yesterday in a hospital in Nongkhai, Thailand, where she had been receiving treatment since Feb 17, said the WHO, which on Feb 27 confirmed the girl as Laos' first avian flu case-patient. Poultry deaths had been reported in the girl's village, a suburb of the capital, Vientiane.

The girl's body was cremated yesterday, with her family's approval, at a Buddhist temple in Thailand to prevent further spread of the disease, the state-run Thai News Agency reported today.

Health officials in Laos are still awaiting final test results on a 42-year-old woman from Vientiane province who died 4 days ago; the WHO has said she probably had the H5N1 virus. If the WHO confirms her case, she will be listed as Laos' second case-patient.

In mid-February outbreaks of H5N1 struck poultry near Vientiane, ending a 6-month period without a major outbreak.

China rejects research findings
Meanwhile, Chinese officials have rejected the findings of an American study that pointed to China's southern province of Guangdong as the source of multiple H5N1 virus strains that spread internationally, according to a report on the China Daily Web site yesterday.

The report, published in an early online edition of the Proceedings of the National Academy of Sciences (PNAS), details how University of California-Irvine (UCI) researchers used genetic and geographic data on the H5N1 virus to chart its history over the past decade, according to a UCI press release. From analyzing 192 samples obtained across Asia and Europe, researchers concluded that several strains of the virus originated in Guangdong province, and they claim to have identified bird migration routes that facilitated the regional and international spread of the virus.

Study coauthor Walter Fitch said in the press release that the findings could help officials more efficiently control the virus at its source. "With a road map of where the strain has migrated, you're more likely to isolate the strain that you should be using to make the vaccine," said Fitch, who is a professor of ecology and evolutionary biology at UCI.

However, He Xia, a spokesperson for the Guangdong Provincial Agricultural Department, told China Daily the researchers' conclusions are flawed and the study lacks credibility. "Actually, Guangong did not witness any bird flu cases in 1996. As a result, the findings are not based on facts," He said.

China's reaction to the report was reminiscent of an episode in November 2006, when another report in PNAS drew criticism from Chinese officials. In that case, US scientists said that a new H5N1 subtype, which they labeled Fujian-like, had become predominant in southern China in the previous year and had been found in human cases. The Chinese agriculture ministry denied that any new strain had emerged.

More poultry outbreaks reported
In other avian flu news, several countries recently reported fresh outbreaks in poultry and other birds:

  • Afghanistan confirmed outbreaks at six more sites in Nangarhar and Kunar provinces in the eastern part of the country and in Kabul, according to an Associated Press report. Recent outbreaks were reported in the eastern city of Jalalabad and in Kunar province.
  • South Korea today confirmed its seventh outbreak in recent months, Reuters reported. The agriculture minister said the outbreak occurred at a poultry farm in Chonan, about 55 miles south of Seoul, which was the site of a similar outbreak in January, the story said.
  • China reported an outbreak at a chicken farm in Tibet, according to a report submitted 2 days ago to the World Organization for Animal Health (OIE). The outbreak, which occurred in Lhassa district, began on Jan 1 and was confirmed on March 5. Tibet's last H5N1 outbreak in birds occurred in May 2006.
  • Vietnam yesterday reported H5N1 outbreaks at two chicken farms on the outskirts of Hanoi, Reuters reported. The disease has also recently struck ducks in the southern province of Vinh Long and chickens in the northern provinces of Hai Duong and Ha Tay, the Reuters report said.

See also:

Mar 8 WHO statement
http://www.who.int/csr/don/2007_03_08/en/index.html

UC Irvine press release
http://www.eurekalert.org/pub_releases/2007-03/uoc--usr030507.php

Wallace RG, Ho Dac HM, Lathrop RH, et al. A statistical phylogeography of influenza A H5N1. Proc Natl Acad Sci 2007 Mar 7 (early online publication) [Abstract]

OIE report on Tibet outbreak

Nov 3, 2006, CIDRAP News story "Study says new H5N1 strain pervades southern China"

Feb 10, 2006, CIDRAP News story "Report depicts China as launching pad for avian flu"

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