H5N1

Idle speculation on the Tennessee avian flu outbreak

Yesterday the Tennessee department of agriculture announced the outbreak of HPAI avian flu, and identified it as an H7 strain. Today the US Department of Agriculture reports that the outbreak seems to have been contained, and we should know the precise strain by sometime Tuesday.

So I dug around in Wikipedia and found no fewer than six varieties of H7 known to infect poultry. Little seems known about H7N1. H7N2 gained recent notoriety when cats in a New York animal shelter contracted it.  H7N3 has been found in both Canada and Mexico (in 2004, it nearly destroyed the poultry industry in the Fraser Valley, Vancouver's back yard—and got me interested in the subject of avian flu). H7N7 caused a serious outbreak in the Netherlands in 2003, infecting 89 people and killing one. H7N8 caused devastation in US turkey farms last year. And H7N9 came out of nowhere four years ago to become a major problem in China.

H7N8 seems the likeliest to be identified as the cause of this outbreak. But if it turns out to be H7N9, we'll be in for a "wait, what?" moment.

Chickens found with genetic resistance to bird flu

Via The Poultry Site: Chickens Found with Genetic Resistance to Bird Flu.

New research carried out at The Pirbright Institute indicates that the genes of some chickens makes them almost resistant to bird flu. 

The findings, which are published in the journal Scientific Reports, show that genetics play a key part in whether the birds are susceptible or resistant to the potentially deadly virus. 

Dr Colin Butter, Reader in Bioveterinary Science at the University of Lincoln, who carried out the research, said: “It is important for us to understand how different genetic lines of birds react to influenza viruses, so that we can begin to understand the spread of the disease. 

"Our results are valuable in emphasising the important role a ‘host’ plays in the spread of avian flu, and also in highlighting a number of factors relating to the chain of infection and control mechanisms which are affected by the route of infection.” 

They found that birds that carried the virus but were genetically resistant to the disease only shed the virus through their respiratory tract and for a limited period of time, whereas birds which were susceptible to the disease, also shed virus in faeces and over a longer time. The researchers discovered that this was the only relevant means of spreading the virus and that resistant birds were therefore unable to initiate or sustain the chain of transmission. 

Further results in the study suggest that this could be due to a genetic restriction within the animal which stops the virus spreading when inside the body. 

Work is being planned to discover and examine the precise biological mechanisms behind genetic resistance. This could have major implications for poultry breeding, as well as human flu treatments, in the future.

Germany culls 10,000 hens after confirmed H7N7 bird flu case

Via Reuters: Germany culls 10,000 hens after confirmed bird flu case. Excerpt:

German authorities have slaughtered around 10,000 hens after a case of bird flu was confirmed at a poultry farm in the northwestern state of Lower Saxony, the state's agriculture ministry said on Monday. 

Germany's animal health body, the Friedrich Loeffler Institute, confirmed the case as high pathogenic H7N7 bird flu. 

The virus has been known to infect pigs and horses as well as birds, but the ministry said it could be transmitted to humans only if they come into close contact with infected animals or their products and secretions. H7N7 infections in humans are generally mild and deaths appear to be extremely rare - the Netherlands reported one fatality in 2003. 

As a precautionary measure, authorities imposed restrictions within a 3 km radius around the farm, and ordered all hens within a 1 km radius to be culled. 

Lower Saxony, a leading poultry production region, reported outbreaks of the H5N8 strain of bird flu in December, as well as cases of the milder, "low pathogenic" form of the H7N7 strain in March and June this year.

Mike Coston at Avian Flu Diary has the story, with some useful background.

CIDRAP: Diverse avian flu strains hit UK, Taiwan, South Africa

Via CIDRAP, Robert Roos describes an increasingly complicated global picture: Diverse avian flu strains hit UK, Taiwan, South Africa. Excerpt:

Several varieties of avian influenza viruses have recently struck farms in the United Kingdom, Taiwan, and South Africa, affecting poultry species ranging from chickens to ostriches, according to reports today. 

In addition, Minnesota officials said recently that a chickadee tested positive for an avian flu virus, but they couldn't determine if it was the highly pathogenic H5N2 virus that hit 108 turkey and chicken farms in the state this past spring.

UK: H7N7 confirmed at Lancashire farm

Via BBC News: Bird flu confirmed at Lancashire farm. Excerpt:

A case of H7N7 bird flu has been confirmed at a poultry farm in Lancashire, the government has said. 

All birds at the farm in Goosnargh, Preston, are being humanely culled, the Department for Environment, Food and Rural Affairs (Defra) said. 

A temporary control zone imposed on Friday at the affected farm has now been replaced by a 10km surveillance zone and an inner 3km protection zone. 

Public Health England says the risk to the public is very low. 

The restrictions mean all poultry farms around the infected premises are not allowed to move poultry, captive birds or other livestock except under licence. 

Defra's chief vet Nigel Gibbens said the restrictions were "part of our tried and tested approach to dealing with previous outbreaks". 

He advised bird keepers to "remain alert" and report any suspected cases to the Animal and Plant Health Agency. 

The H7N7 strain is highly contagious in flocks and can cause deaths in birds, but is "very rare" in humans, the NHS says.

CIDRAP: Avian flu in South Korea, Taiwan prompts massive culling

Via CIDRAP, Robert Roos writes: Avian flu in South Korea, Taiwan prompts massive culling. Click through for the full report, which includes outbreaks in Vietnam and Germany as well. Excerpt:

South Korea and Taiwan have destroyed more than 2.7 million poultry in recent weeks and months in efforts to halt highly pathogenic avian influenza (HPAI) outbreaks of the H5N8 and H5N2 varieties, according to reports posted yesterday by the World Organization for Animal Health (OIE). 

In addition, South Vietnam has reported another H5N1 avian flu outbreak, and low-pathogenicity avian flu (LPAI) H7N7 recently struck a turkey farm in Germany, according to media and OIE reports. 

The latest outbreaks prolong a string of avian flu episodes that have surfaced this winter in Asia, Europe, North America, and Africa. Last week the World Health Organization said the diversity and geographic extent of recent avian flu outbreaks are greater than at any time since the debut of modern surveillance methods. 

South Korea cites 65 H5N8 outbreaks 

A South Korean report posted by the OIE yesterday describes 65 H5N8 outbreaks dating all the way from late last September to late January and involving about 2.6 million poultry. The report profiles 22 stand-alone outbreaks and "outbreak clusters" including from 2 to 13 individual incidents. 

The affected sites had a total of 2,589,062 birds, including ducks, chickens, geese, and doves. Only 177 cases, all fatal, were reported, but all the rest of the birds were destroyed to stop the virus. Most of the outbreaks were in the southwest and northwest of the country, with a few in the southeast, according to a map in the report. 

South Korea had widespread H5N8 outbreaks in January and February of 2014, followed by isolated outbreaks in June and July.

CIDRAP: Avian flu findings reported in 6 far-flung nations

Via CIDRAP, Robert Roos writes: Avian flu findings reported in 6 far-flung nations. Excerpt:

Reports of avian influenza detections continued over the past few days, with findings in poultry and wild birds in the United States, the United Kingdom, Israel, Japan, and Bulgaria, and even a dog got into the act in South Korea. 

In the United States, a dead mallard duck was found infected with highly pathogenic avian flu (HPAI) H5N8 in southeastern Nevada, marking the first detection of HPAI in the state, according to a Jan 30 media report quoting the Nevada Department of Agriculture. 

KTVN, a TV station in Reno, Nev., said the duck was found in Lincoln County Jan 23 and tested positive at the California Animal Health and Food Safety Laboratory. State officials said they would work with the US Department of Agriculture (USDA) to monitor the situation. 

The report follows several detections of H5N8 in wild birds, backyard poultry flocks, and at least one commercial poultry flock in western states in the past 2 months. On Jan 24 the USDA said the virus had turned up on a turkey farm in California's Central Valley. 

H7 on UK chicken farm 

In the United Kingdom, authorities today reported an outbreak of a "low severity" H7 avian flu in chickens on a Hampshire farm. A UK government statement said the strain is much less severe than the H5N8 virus that hit a Yorkshire duck farm in November. 

The statement said poultry movements will be restricted within 1 kilometer of the farm, and the chickens will be humanely culled. 

An official with the UK Food Standards Agency said indications are that the virus is an H7N7 subtype, but further confirmatory testing is needed, according to a BBC News story today. Officials said the strain poses very little risk to human health, according to the story. 

H5 in Israel, Japan, Bulgaria 

In Israel, highly pathogenic H5N1 struck another turkey farm, this one near Netanya, a coastal city about 35 miles south of Haifa, according to a short item in the Jerusalem Post today.  It said the virus hit a coop housing 37,000 turkeys, which will be killed and buried. 

H5N1 had struck a turkey farm in the Haifa area Jan 14, and about a week later it hit chickens and turkeys in Hadera, about 28 miles from Haifa, according to previous reports. 

Meanwhile, Japanese officials told the World Organization for Animal Health (OIE) on Jan 30 that they had found a dead mallard infected with H5N8. The duck was found in southwestern Japan's Kagoshima province on Jan 14 and tested positive on Jan 19, the report said.

Hong Kong: HKU team hail H7N9 flu vaccine 'breakthrough'

Via the South China Morning Post, an April 2 report: HKU team hail H7N9 flu vaccine 'breakthrough'. Excerpt:

University of Hong Kong researchers have developed a vaccine that may be the first in the world to offer a shield against many influenza viruses - including the deadly H7N9 bird flu strain - in one simple shot. 

The HKU team described it as a breakthrough for seasonal flu vaccines, which can usually only provide protection against one or a few specific viral subtypes each. 

The study found the new vaccine helped 80 to 100 per cent of mice fight different strains of flu viruses. 

"Current influenza vaccines target only specific and individual subtypes, but it is difficult for scientists to predict which types of a virus will cause the next pandemic," the lead researcher, associate professor of public health Dr Leo Poon Lit-man, told the South China Morning Post. 

"That is the reason why we should study whether there is another way to offer a broader spectrum of protection against different subtypes of viruses." 

But it might take years before the vaccine is tested in human clinical trials, Poon said. 

HKU led the study with technical help from the United States' National Cancer Institute. It published the findings in international scientific journal Proceedings of the National Academy of Sciences of the United States of America yesterday. 

The researchers used the vaccinia virus - the key ingredient in the smallpox vaccine - as a vaccine carrier. The vaccinia virus is known to be able to induce robust protection in mice against the H5 type of influenza A viruses. 

They tested hundreds of mice infected with various viral strains, including H3N2, H1N1, H7N7 and the most recent to surface among humans, H7N9. 

Of the mice that were injected with the vaccine, 80 to 100 per cent were protected from subsequent viral attacks. 

Among those that did not receive a jab, none survived.

Expect more bird flu viruses to jump to humans, warns health official in China

Via The Globe and Mail, a report by Nathan VanderKlippe: Expect more bird flu viruses to jump to humans, warns health official in China.

The lead World Health Organization official in China expects more bird flu viruses to jump to humans in the country after two new strains, H7N9 and H10N8, emerged fewer than 12 months apart. 

“We do expect to see more such strains pop up,” said Bernhard Schwartlander, the Beijing-based WHO China representative. Bird flu cases have tended to carry unusually high fatality rates, and the prospect of a novel strain taking root in human populations, and possibly jumping between people, is a continued source of anxiety for those monitoring global public health. 

“We are nervous, because we know that things can change, and that may cause big problems,” said Dr. Schwartlander in an interview Wednesday. “We need to be very careful and be on alert. That’s very clear.” 

The discovery of H10N8, which killed a 73-year-old Chinese woman in December and sickened another, marks the fifth strain of avian influenza to jump from birds to humans in 17 years. It comes after H7N9 was discovered last February. That virus has since killed at least 70 world-wide. 

On Tuesday, Chinese researchers reported in the Lancet that the H10N8 shares much of its genetic base with H5N1, the bird flu strain that emerged in 2009 that has killed some 386 people, including an Alberta woman who died Jan. 3, in the first North American death. A genetic mutation allows H10N8 to better adapt to mammals, making it a particular cause for concern. 

And researchers have already identified other potentially dangerous viruses lurking in the shadows. Last August, scientists working with the H7N7 virus, which already exists in the Chinese poultry population, said it too was capable of jumping to mammals in lab tests. If it continues to circulate, “I am sure that human infection cases will occur,” University of Hong Kong researcher Guan Yi said then. 

Still, health officials have found no evidence of sustained human-to-human bird flu transmissions, including over the ongoing Chinese lunar new year season, when the risk of such transmission is particularly high as hundreds of millions of people jam into trains, buses and cars to visit home. 

“That’s the good news. The bad news, of course, is that may change, and that’s in the nature of the virus,” said Dr. Schwartlander. “The influenza virus has the ability to shift, to change over time.”

Australia: Second farm shut down by H7 outbreak

Via The Daily Advertiser: Second farm shutdown by bird flu. Excerpt:

A second egg farm has been quarantined after H7 Avian Influenza was found on the property north of Young. 

The NSW Department of Primary Industries' first response team has the property under lockdown and planning is underway for eradication of the virus in line with nationally agreed protocols. 

It follows from a case last week were the same strain was found in a flock of layer hens near Young. 

NSW chief veterinary officer Ian Roth believes the two cases are linked. 

“It is believed that the second case may be linked to the initial facility. Further tracing is underway to determine whether this is the case," he said. 

“The virus is definitely not the highly pathogenic H5N1 strain that has gained worldwide attention - nor is it closely related to that strain.”