Updated, Sunday AM, 26April2009
From www.seattlepi.com/ :The worrisome new virus - which combines genetic material from pigs, birds and humans in a way researchers have not seen before - also sickened at least eight people in Texas and California, though there have been no deaths in the U.S.
"We are very, very concerned," World Health Organization spokesman Thomas Abraham said. "We have what appears to be a novel virus and it has spread from human to human ... It's all hands on deck at the moment."
For background on Influenza, from Individ, I will reproduce part of my old post from 2006 below the "fold". Over 60 people have died and over 1000 are infected with this swine flu strain in Mexico, and it's spread to California and Texas. NOW, students from NYC are also suspected as having it. Most of the dead in Mexico were aged between 25 and 45.Sounds "viral" to me. Obama appears to be a global governance type, so with him in charge, don't expect the Southern border with Mexico to be closed, especially when we see headlines like
this:
WHO rejects closure of Mexican border despite swine flu outbreak
Good to know WHO runs the country now?
Who's on first?Here is the latest from the CDC via wikipedia: "The current vaccine against the seasonal influenza strain H1N1 is thought to be unlikely to provide protection. Anne Schuchat, director of CDC's National Center for Immunization and Respiratory Diseases, said that the United States cases were found to be made up of genetic elements from four different flu viruses—North American swine influenza, North American avian influenza, human influenza A virus subtype H1N1, and swine influenza virus typically found in Asia and Europe. For two cases a complete genome sequence had been obtained. She said that the virus was resistant to amantadine and rimantadine, but susceptible to oseltamivir (Tamiflu) and zanamivir (Relenza)."
The dunce who runs Homeland Security will probably close the Canadian Border. If we get into a swine flu SHTF situation, then a good
N95 mask is recommended. You might want to bone up on a good survival podcast, just in case.
Here is a pretty balanced one.
Weird virus, I say. It's an A/H1N1 virus, but with a strange four part genetic code, with strands from four different viruses? Hmmm. This plot is going to thicken. Mark my words.
Hey Janet and Barack: close the freakin' border.
Individ
-----------The Fold------------------------------
Individ's Textbook on The Flu, Bird Flu, Influenza, The Grippe...
I had a little bird,
Its name was Enza.
I opened the window,
And in-flu-enza
(A Children’s rhyme from 1918).
The Germ Theory and Pandemics
According to the
Germ Theory of Disease, specific microorganisms (germs) are responsible for causing specific diseases (See
“Koch’s Postulates” for a systematization of the Germ Theory).
The Spanish Flu, also known as La Grippe Espagnole, or simply, The Grippe, was an unusually severe and deadly strain of influenza, or “the Flu”, which we now know to be a viral infectious disease.
The “Spanish Flu” killed some 50 million to 100 million people worldwide, from 1918 and 1919. A disease that attacks a large fraction of the population in every region of the world is called a
pandemic.
Until the advent of AIDS, influenza was the last uncontrolled pandemic killer of humans (
Small and Bender, 2001).
What is the Flu?
Influenza is a prostrating, often severe, viral infection of the lungs characterized by fever, cough, and severe muscle aches. In the elderly and infirm, it is a major cause of disability and death, often as a result of secondary bacterial infections. Gastrointestinal disturbances may also occur. Further, there is no such thing as “stomach flu”, and a low fever with sniffles that keeps you in bed for a day may be a “cold”, but is decidedly not the flu.
OK, let's back up, and investigate a little of the history, microbiology, and biochemistry of "influenza". The term influenza is of Italian origin, and dates from a 1743 outbreak of the disease in Europe that began in Italy. In Italian, influenza, means "epidemic," and originally referred to a "visitation or influence of the stars",(with an etymology from the Middle Latin influentia).
Research during the time of the Spanish Flu first identified viruses as disease causing agents, and it was at that time that both Virology and the study of the flu began in earnest.
The Virus
Virus particles are smaller than bacteria (bacteria are singled celled, living organisms) , and can be considered as small groups of large molecules. The influenza-causing viruses constitute the Orthomyxoviridae family of RNA viruses designated as types A, B, and C. Most scientists consider viruses to be non-living, because they require a host cell (as in our bodies, or in the body of a bird) to reproduce. Types B and C generally cause only minor illness, but Small and Bender, Ibid, point out that influenza A, (or Avian Flu viruses), are the causative agent for pandemics. Cold preserves the viruses, whereas heat destroys them.
Recurring influenza outbreaks occur because the viruses undergo periodic "reassortment". The virus has two outer membrane glycoproteins, hemagglutinin (H) and neuraminidase (N) (see below). Their variations are numbered, so H1 is slightly different from H2. These surface glycoproteins can evolve, for example, from H1N1 to H2N2 as it did in 1957 (Asian Flu, 1 to 1.5 million deaths attributed) and from H2N2 to H3N2 as it did in 1968 (Hong Kong Flu, 3/4 to 1 million deaths attributed) , thus introducing a new virus into a population that has no protective serum antibody. The Spanish Flu was caused by the H1N1 type of influenza virus, which is similar to the bird flu of today, which is mainly mainly H5N1 and H5N2. I will discuss the H and N biochemistry below. No different subtypes of H and N have been identified for influenza B and C.
Virus biochemistry
The outer surface of the virus (an individual virus particle is called a virion, but I will avoid that usage here) contains the two glycoproteins, hemagglutinin and neuraminidase, embedded in the virus's lipid (i.e., fat) membrane, or envelope. These are the "studs" shown in both the cartoon and the photo; in the photo, the black bar, shown for scale, is 1/10,000 of a millimeter long.
Influenza A viruses are either spherical (0.08 -0.120 micrometers in diameter), or filament-like (and up to 0.3 micrometers in length). A typical influenza virus particle contains about400 molecules of hemagglutinin glycoprotein (H) and 100 molecules of neuraminidase glycoprotein (N) , studded over the surface. The are embedded in a host-derived lipid, two-layer membrane. The core of the virus contains a single stranded piece of RNA. The influenza virus genome comprises eight segments; a feature that enables “gene swapping” reassortment.
Proteins are biological macromolecules made up of different amino acids [click here to see a figure that shows their molecular structure], in the same way that a freight train is composed of different types of freight cars. Proteins perform a very wide range of biological functions. Glycoproteins are even more complex, in that they are unions of a protein and a sugar molecule. We are all aware of how well sugar dissolves in water - the marrying of the protein with a sugar molecule in the hemagglutinin coat of the flu virus is what makes the viruses sooo happy in the watery environment around your cells and in your mucus, saliva, and blood.
Neuraminidase is the common name for acetyl-neuraminyl hydrolase. This glycoprotein is an enzyme (you can tell that from the -ase ending in the name) that allows the virus particle to both enter the cells in your body to initiate viral reproduction, and then to allow the newly birthed virus to pass out of your cells. The activity of neuraminidase also disrupts the mucous that is present in the respiratory tract, and further, it keeps the viruses from clumping with other virus particles. The result of these activities is to ease the spread of the virus through the respiratory tract. Two different variations of neuraminidase, designated N1 and N2, are important in human infections, and hence, most flu-causing virus end with the designation N1 or N2. Influenza A viruses have 16 H subtypes and 9 N subtypes. The surface glycoproteins are also what trigger our immune system to attack the virus particles: particularly hemagglutinin, the main target of flu-fighting antibodies.
Within the viral membrane are eight strands of RNA, which carry a total of just eight genes. Two of the genes produce the sugar-rich proteins hemagglutinin and neuraminidase.
Influenza is for the Birds
Most people don't realize that all flu outbreaks originate from birds. Fifteen subtypes of influenza A virus are known to infect birds, providing an extensive reservoir of influenza viruses that constantly circulate in bird populations. First identified in Italy more than 100 years ago, avian influenza, or “bird flu”, is a contagious disease caused by viruses that normally infect only birds and, less commonly, pigs.
Avian viruses are highly species-specific, but have, on rare occasions, crossed the species barrier to infect humans. All birds seem to be susceptible to infection, though some species are more resistant. Infection s in birds can range from mild illness to “highly pathogenic avian influenza” (HPAI), a highly contagious and rapidly fatal disease resulting in severe epidemics with fatality rates that near 100%.
Migratory waterfowl, especially wild ducks , geese and swan, are the natural carriers of avian viruses; however, these birds are also the most resistant to infection. Domestic poultry are particularly susceptible to epidemics of the rapidly fatal influenzas. So far, outbreaks of the nastiest forms have been caused by influenza A viruses of subtypes H5 and H7.
Avian flu is spread to humans through domestic poultry, both through infected birds and poultry products, and though the use of infected manure (used as fertiliser) or feed. Infected birds shed influenza virus in their saliva, nasal secretions, and fecal droppings. Humans with H5N1 have typically caught it from chickens, which were in turn infected by other poultry or waterfowl. People in Asia can live or work very closely with fowl in crowded conditions, and they apparently inhale aerosolized particles of chicken manure, etc.; this apparently is a major factor in the spread of flu to people, and why so many strains of flu come from Asia.
Antibodies and Vaccines
When we catch the flu, we are usually being infected by H1 or H3 flu strains, and our bodies may be able to mount a partial defense, as our bodies can recognize them from previous infections. Occasionally, genetically unique strains emerge. But in 1997, H5 strains, which had been restricted to birds, created a new glycoprotein coat that was new to our antibody defense systems. We therefore now see the modern H5N1 strain that has killed a good portion of the few people who have been infected by contact with birds:
The Bird Flu.
Regular winter flu shots are made with killed influenza viruses. The government is stockpiling experimental bird-flu vaccine made the same way, but must be manufactured to combat flu-causing viruses that exist NOW. The current Bird Flu is able to infect people, but is difficult, if not impossible, to transmit from person to person.
