Courtesy The Pug FatherNo need to put down your pork chops, as health officials are quick to remind us: you can't get swine flu from eating products made from pigs. In fact, health officials have yet to find a pig with this particular strain of the virus. According to the CDC, the virus that's been making headlines this week contains not only pig, but also human and bird flu DNA. Viruses are complicated and mutate as they go from one host to the next, so it's difficult to tell just where novel strains originate. All of this has left many people to question whether it's appropriate to call the virus "swine flu" at all?
Pork producers say: leave pigs out of this!
They're afraid that the name "swine flu" will cause demand for their products to plummet, and have asked government officials and the news media to call the virus by it's scientific name, H1N1, which refers to the serotype of the virus - its particular chemical make-up. It's a rational fear on their part. Some countries have already banned meat and pork products from Mexico and parts of the US due to fear over the spread of the disease.
What do you think? Would a flu by any other name...smell like meat? When it comes to novel viruses like this one, what's in a name?
Phylogeographer Robert Wallace has Bird Flu on the brain. Like many scientific researchers, when birds and people in Asia started dying from the virus he became concerned about the possibility of a flu pandemic. Biologists know that if the bird flu virus mutates in such a way that it can pass easily between humans, millions of people worldwide could die from the disease. What no one knows for sure is when and where this mutation will take place.
With the help of his colleagues Wallace is studying the factors that contribute to outbreaks of virulent bird flu. They do this by using DNA from different strains of the virus to understand how it has changed and spread over time and distance, an area of research known as Phylogeography. Their hope is that by understanding how and where the virus mutates they can help predict, and maybe even prevent, some of the factors that could contribute to a pandemic strain of this disease. You can read an article about their recent study here.
So far Wallace and his colleagues have been able to piece together the road trip that Bird Flu has taken, and what they've found might make those of us who love chicken nuggets (and sandwiches, and lunch meats) a little uncomfortable. While you can't catch Bird Flu from eating chicken nuggets, it appears that industrial poultry production might be the perfect incubator for virulent strains of this disease. Wallace fears that if large poultry producers don't change their practices, they could eventually produce more than cheap chicken - they could breed a pandemic strain of bird flu.
But how does this work? Well, like lots of things, it's complicated. Generally speaking: because big poultry producers keep large numbers of genetically similar birds in one area, and because the immune systems of these birds are weakened by being crammed into cages and fed a poor diet, and also because new generations of birds are grown-up and shipped out quickly to make room for others, bird flu viruses can easily mutate and spread through the population. In some countries industrial production is happening in close proximity to wild populations of birds or to free-grazing domestic flocks - making it easy for these virulent strains to hitch a ride.
When you add all of this up, it starts to look as though there is a real connection between how we produce the food we eat and the diseases that threaten our health and well being. The question that comes next is how much are we willing to risk for a cheap chicken sandwich?
Courtesy broterham A two year old girl in northern China has tested positive for bird flu. Early this month, January 5, a 19-year-old Beijing woman died of bird flu after handling poultry. She had purchased ducks at a market in Hebei Province, which neighbors Beijing. Although she had close contact with 116 people, no one around her has fallen ill.
Human-to-human transmission of avian flu is rare, but officials worry the virus could mutate and become a deadly pandemic. H5N1 has led to 248 deaths worldwide since 2003, including 21 in China.
Click this link to read all CNN articles about bird flu
Officials from the World Health Organization are visiting Pakistan to investigate several cases of bird flu in humans. The disease, which is very similar to human influenza, has not yet been shown to be contagious -- you can catch it from birds, but not from another person. If it ever mutates into a form that can be transmitted person-to-person, that could have very dire consequences -- people have no immunity to the disease, and there is no vaccine yet.
The antibodies worked well when administered three days after the mice were infected, with all 20 mice in the treatment groups surviving, compared with none out of five in the control group. Antibody-producing white blood cells, called memory B cells, were separated from the blood of four Vietnamese who had recovered from H5N1 influenza (bird flu). In Switzerland, Dr. Lanzavecchia treated them with a process he developed so that they rapidly and continuously produced large amounts of antibody.
Next, researchers in Dr. Subbarao's lab screened 11,000 antibody-containing samples provided by the Swiss team and found a handful able to neutralize H5N1 influenza virus. Based on these results, Dr. Lanzavecchia purified the B cells and ultimately created four monoclonal antibodies (mAbs) that secrete H5N1-specific neutralizing antibodies." Science Daily
Using blood products from influenza survivors is an old idea, the researchers note. During the flu pandemic of 1918-19, for example, physicians took serum from recovered flu patients and gave it to new victims. A recent study suggests it halved the death rate, from 37% to 16%.
The new antibody treatment could be used together with antivirals:
“What we are trying to do is add another arrow to the quiver of options for treating patients with H5N1 infection," says Cameron Simmons, who led the study. New Scientist
Because the survival rate was excellent even when treatment was delayed for three days, this antibody treatment would work well in treating the few people who catch the disease directly from birds, and for localized outbreaks. For large scale prevention against bird flu, antiviral drugs such as Tamiflu are the still the best defense.
Research article in PLoS Medicine: Prophylactic and Therapeutic Efficacy of Human Monoclonal Antibodies against H5N1 Influenza.
Researchers report that bird flu mutates in cats faster than previously thought. Many human diseases originate in other animals, eventually mutating into a form that can infect us. AIDS is believed to have evolved from a similar disease in apes, and various strains of human flu reside in birds and farm animals before mutating and passing on to humans.
So far, very few people have been infected with "Bird flu" -- it seems to be hard for us to catch in its current form. But if it takes up residence in another mammal, it could mutate into a form that's much more deadly to us.
In the immortal words of Jan Hobson, it's time to throw your cat away.
Gill tested blood from 39 duck hunters for antibodies that would prove infection by any of a dozen kinds of bird-based influenza. Several hunters had antibodies to H1, H2, and H3 strains, which have adapted to humans and are now routinely seen in people. But one hunter tested positive for H11N9, which is not seen in humans.
The hunter was a healthy, 39-year-old man who'd been hunting since he was 8 and kills or handles hundreds of birds a year. He'd never shown any symptoms of illness.
Also, Gill found H11N9 antibodies in the blood of two Iowa Department of Natural Resources workers. Both had been banding ducks for years.
None of the infected men had any history of working with domesticated birds--an established source of bird flu transmission to humans. Instead, these cases appear to be the first documented of humans getting viruses from wild birds.
Current flu vaccines require live chicken eggs and six months of brewing time. This method may provide too little, too late. A new, quicker, type of vaccine production and delivery system has been approved for trial in August. A company called PowderMed has produced vaccine by cloning a gene from the current circulating bird flu strain and slotting it into an existing DNA backbone vaccine. This "plug and play" system would enable rapid adaptation of the vaccine to include relevant DNA if a new and more dangerous strain develops. It is then enclosed in tiny gold particles and delivered using an injector powered by concentrated helium gas, which pushes the particles into the skin.
“We are very excited by the potential for our flu vaccine technology to address the major healthcare challenge that influenza presents, in particular in the event of an avian flu or other pandemic outbreak. Our technology has significant advantages over current flu vaccine technology particularly in terms of the speed of response in the event of a pandemic. As soon as a new influenza strain becomes known, our “plug and play” system would enable us to rapidly insert the relevant DNA gene cassette into our standard DNA backbone. A PowderMed manufacturing facility will be capable of delivering the vaccine requirements of an entire country within 3 months. This is not possible for other technologies.”
Just 1.2kg of vaccine DNA would be sufficient to vaccinate the entire population of the US twice - an initial dose and a booster dose. PowderMed has carried out a detailed feasibility study with contract manufacturing partners, which concludes that it could establish a manufacturing capability with a surge capacity of 150 million influenza vaccine doses in a three-month period. Dr Dix points out that this is critical since, “No other vaccine technology offers this speed of response. In the event of a pandemic, most deaths and illness will occur in the first six months of an outbreak. We believe that our technology offers the best potential to save lives and minimise the economic impact of a flu pandemic.” Dr Clive Dix, CEO of PowderMed