Source and full article The 2013 outbreak of avian-origin H7N9 influenza in eastern China has raised concerns about its ability to transmit in the human population. The hemagglutinin glycoprotein of most human H7N9 viruses carries Leu226, a residue linked to adaptation of H2N2 and H3N2 pandemic viruses to human receptors. However, glycan array analysis of the H7 hemagglutinin reveals negligible binding to humanlike α2-6–linked receptors and strong preference for a subset of avian-like α2-3–linked glycans recognized by all avian H7 viruses. Crystal structures of H7N9 hemagglutinin and six hemagglutinin-glycan complexes have elucidated the structural basis for preferential recognition of avian-like receptors. These findings suggest that the current human H7N9 viruses are poorly adapted for efficient human-to-human transmission.
Source and full article LA JOLLA, CA—December 5, 2013—Avian influenza virus H7N9, which killed several dozen people in China earlier this year, has not yet acquired the changes needed to infect humans easily, according to a new study by scientists at The Scripps Research Institute (TSRI). In contrast to some initial studies that had suggested that H7N9 poses an imminent risk of a global pandemic, the new research found, based on analyses of virus samples from the Chinese outbreak, that H7N9 is still mainly adapted for infecting birds, not humans.
"Luckily, H7N9 viruses just don’t yet seem well adapted for binding to human receptors," said Ian A. Wilson, the Hansen Professor of Structural Biology and chair of the Department of Integrative Structural and Computational Biology at TSRI.
Source and full article AuthorsLiu W, et al. Show all Journal
Euro Surveill. 2013 Nov 21;18(47). pii: 20640.
Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
Source and full article The method we describe here to produce these molecules is straight forward and can facilitate research in influenza laboratories, since it allows for production of large amounts of proteins fast and at a low cost. Although here we focus on influenza virus surface glycoproteins, this method can also be used to produce other viral and cellular surface proteins
Source and full article A total of 26 HA gene and AA and 24 NA gene and AA sequences were analyzed. HA, NA gene and AA sequence of H7N9 virus were conservative in America but not in Eurasian area. The HA and NA gene evolutions could be divided into 2 general systems: Eurasian and America. Only one basic AA R (Arg) was close to HA cleavage sites of H7N9 virus. Regional differences existed between HA protein cleavage and NA protein glycosylation sites. And the HA glycosylation sites were conservative. Several antigenicity sites of HA and NA protein changed in Eurasian area and America. In 7 cases, novel H7N9 evolved virus isolated from China were one branch of Eurasian area. Five AAs were deleted in stalk region of NA residues 69 to 73. HA protein cleavage and glycosylation sites did not carry the variant. However, several antigenicity sites of HA and NA protein changed compared with other virus strains. CONCLUSIONS: Regional differences exist in HA and NA gene evolution of H7N9 virus. The deletion of 5 AAs in stalk and the variation of several antigenicity sites of HA and NA protein may lead to an outbreak of H7N9 virus in humans.
Source and full article 1. A patient who consulted Dr Wong Chun-yan and presented with non-specific symptoms tested negative for the avian influenza A(H7N9) virus; and
2. Twelve HCWs of TMH and QMH who presented with non-specific symptoms tested negative for the avian influenza A(H7N9) virus.
Source and full article Analysis of results of two assessments in 36 countries shows statistically significant improvement in all 12 capabilities on an aggregate level and 47 of 50 indicators.
Source and full article Shenzhen poultry markets have intensified their disinfection measures and monitoring, the Southern Metropolis Daily reported yesterday, citing market administrators.
“We’re now doing three to four times the normal amount of disinfection work in the market every day, and will arrange professional cleaners to clean the trade area after daily sales peaks,” said an administrator of a wholesale market in Nanshan District.
Source and full article Influenza vaccine is moderately effective for preventing influenza illness. It is not known if vaccination reduces the risk of subsequent hospital admission among patients with vaccine failure and laboratory confirmed influenza illness.
Source and full article Health officials say the Indonesian helper who contracted the H7N9 virus remains in critical condition in hospital. They say she’s developed fever, but her vital organs are still functioning. A patient who shared a ward with the woman in Tuen Mun Hospital has developed flu symptoms.
Source and full article A/Hong Kong/5942/2013 also had same relationship with H7, N9, MP, and NS, including the presence of Q226L in H7. In addition, the H7 sequence had T131A, which was also uniquely found in A/Guangdong/1/2013. Similarly, the PB2 had E627K and was closely related to the PB2 in A/Guangdong/1/2013. However, the other three internal genes (PB1, PA, NP) were related to H9N2 sequences circulating in southern China (largely Hong Kong), but were distinct from the A/Guangdong/1/2013 sequences.
Thus, A/Hong Kong/5942/2013 represents an independent introduction into humans, which reflects a constellation circulating in southern China that is distinct from the August H7N9 from Guangdong Province. This sequence data indicates H7N9 circulating in southern China is readily distinguished from the former and recent sequences in northern China, and there is significant heterogeneity in the southern sequences signaling widespread H7N9 in poultry in southern China.
Source and full article About 40 staff members would be added to border checkpoints to run temperature tests on travellers, Leung said.
Public hospitals were urged to perform more thorough tests on suspected H7N9 cases, since Tri was diagnosed only upon more comprehensive testing, the Hospital Authority’s chief infection control officer Dr Dominic Tsang Ngai-chong said.
Across the border, attitudes towards the virus were more relaxed in the government and media. Sterilisation measures were little used at Shenzhen’s markets.
Source and full article Two private clinics in Tuen Mun remained open yesterday after they were identified as having treated an Indonesian domestic helper later diagnosed to be infected with the deadly H7N9 strain of bird flu. The two doctors who saw the ill helper late last month, along with nurses and patients who were present when she sought treatment, are among more than 200 people placed under observation by health authorities. Yesterday, a patient at the clinic of Dr Simon Wong Siu-shan said he was not worried the doctor might have been infected. "There is unlikely to be a big risk," the man said after consulting Wong, who treated H7N9 patient Tri Mawarti, 36, at his Castle Peak Road clinic on November 25. A nurse said Wong was busy seeing patients and had declined to be interviewed.
Source and full article (v) The Agriculture, Fisheries and Conservation Department (AFCD) conducted visits to 15 local chicken farms and taken specimens for testing on December 3. No irregularity was detected. It will conduct visits to the remaining 15 local chicken farms today. At the same time, AFCD will continue to inspect the poultry wholesale market, Yuen Po Street Bird Garden and pet bird shops etc. to ensure that the birds are in healthy and normal condition. It has also issued letters to the trade reminding them to stay alert and strictly follow the biosecurity and hygiene measures. AFCD will continue to take samples from dead birds and poultry for testing of avian influenza.
Source and full article A spokesman for the Housing Department (HD) said today (December 4) that following the first confirmed human case of avian influenza A(H7N9) in Hong Kong, the HD has put in place corresponding preventive measures, including stepping up cleaning work at potential hygiene black spots to ensure that its public rental housing estates and markets are maintained in hygienic conditions.