H5N1 strikes again in Vietnam as European countries report more H5N8
Vietnam today reported another highly pathogenic H5N1 avian flu outbreak, as two European countries—Romania and Slovenia—reported several more H5N8 outbreaks in wild birds and poultry, according to the latest updates from the World Organization for Animal Health (OIE).
In Vietnam, the new H5N1 event began on Mar 15 in backyard poultry in Can Tho province in the southern part of the country. The virus killed 396 of 794 susceptible birds, and authorities culled the remaining ones as part of the outbreak response. Since the first of the year, Vietnam has reported several H5N1 outbreaks and is also battling H5N6.
Elsewhere, Romanian veterinary officials reported 19 more H5N8 outbreaks, 17 in backyard poultry and 2 involving wild birds. Most were reported from Teleorman County in the south, with other locations including Bucharest, the country's capital, and Constanta County. The outbreaks began from Feb 23 to Mar 17, killing 167 of 501 poultry, plus 4 wild birds.
Slovenia reported 10 more outbreaks involving 253 wild birds—all but 3 were mute swans— found dead from Jan 26 to Feb 17 in four municipalities.
Mar 22 OIE report on H5N1 in Vietnam
Mar 21 OIE report on H5N8 in Romania
Mar 22 OIE report on H5N8 in Slovenia
H7N9 mutation noted that could affect ability to infect poultry, people
A research team from Hong Kong University (HKU) yesterday described a mutation in an H7N9 virus isolated in China that gives the virus the capacity to infect humans while circulating in poultry. They reported their findings in Nature Communications.
After analyzing the genome of a 2013 H7N9 virus, they identified unique NS-G540A substitution that it inherited from the H9N2 virus that provided the internal genes for H7N9. For H7N9, the mutation enhanced replication in mammalian cells and mice, while retaining the ability to replicate in avian cells.
They note that the endemic nature of H7N9 and persistent reemergence in humans is unusual, but add that their findings provide a possible mechanism to explain the pattern.
Chen Honglin, PhD, corresponding author and professor at State Key Laboratory for Emerging Infectious Diseases at HKU, said in an HKU news release that the mutation could provide an important biomarker for monitoring the emergence and transmission of avian flu viruses in humans and preventing human-to-human infection. "The mutation can also serve as a novel target of anti-influenza drug development," he said.
Mar 21 Nat Commun abstract
Mar 22 HKU news release