Dumb question?

[ema-adama]

Perhaps this has already been addressed and I missed it.

http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5707a1.htm

Biology of Influenza
Influenza A and B are the two types of influenza viruses that cause epidemic human disease. Influenza A viruses are categorized into subtypes on the basis of two surface antigens: hemagglutinin and neuraminidase. Since 1977, influenza A (H1N1) viruses, influenza A (H3N2) viruses, and influenza B viruses have circulated globally. Influenza A (H1N2) viruses that probably emerged after genetic reassortment between human A (H3N2) and A (H1N1) viruses also have been identified in some influenza seasons. Both influenza A subtypes and B viruses are further separated into groups on the basis of antigenic similarities. New influenza virus variants result from frequent antigenic change (i.e., antigenic drift) resulting from point mutations that occur during viral replication (13).
So, H1N1 has been in circulation since 1977, or since April 2009? Are there two different H1N1's?

I have never taken the flu seriously and so never really bothered to educate myself on this topic.

[ema-adama]

Oh, and why do the authorities predict H1N1 in addition to the 'regular' flu? Aren't there normally 3 or more viruses doing the rounds? I don't get why they think that H1N1 is going to be in addition to any other 'regular' viruses?

I feel like a bit of an idiot to be honest.... :alien:

[bbrandonsmom]

I read on wikipedia today that it is a "new" strain composed of the combined-avian, pig and some thing else. Made me wonder how it all got mixed together in the first place? Wiki could be wrong, I was just curiouse about when it started since I saw a ref to 1976 as well, so looked it up.

[ema-adama]

I read it was a mutation of human, avian and pig. I guess I don't understand how it got it's name H1N1. If anyone else has info, it would satisfy my curiosity.

Is there anywhere you can find out which strains will be in the 'regular' flu vax and how it was decided that those strains will be expected in addition to h1N1?

[ema-adama]

The influenza A(H1N1) virus is a new human virus resulting from a combination of segments of genes with different origins, porcine, avian and human. This virus was first detected in Mexico in March 2009 and is characterised by human-to-human transmission.

http://www.grippe.public.lu/questions_reponses/grippeporcine/grippeAH1N1_

So, H1N1 was first deteccted in March 2009? Or 1977 as is stated in cdc?


http://wizbangblog.com/content/2009/08/25/some-perspective-on-the-h1n1-virus-1.php


Calling it H1N1 is a misnomer because there are many other strains of H1N1, including the 1918 Spanish flu. Calling it novel H1N1 is just as much a misnomer because every new strain is novel. Same for calling it the Swine flu as there and many types of Swine flu that are subtype H1N2, H3N1, H3N2, and H2N3.
In respect to the naming convention that's been in place for nearly a hundred years and which has bought us names like Spanish flu, Asian flu, Hong Kong flu, Russian flu, Wisconsin flu, and Fuji flu, this new flu should be called Mexican flu, and in fact that's what it's called in other parts of the world such as Thailand and Israel.
Ultimately, the Mexican flu will become just another of the many strains that float around without causing much concern beyond any other known human to human transmittable flu. The over reaction to Mexican flu serves a useful purpose in preparing us for when a truly dangerous new strain pops up.
The odds that the Mexican flu will mutate into some deadlier form are extremely remote. Its funny that those who profess evolution the loudest seem to understand it the least. The survival of a given flu strain is a race between variations to infect as many hosts as quickly as possible. The more virulent a variations is the slower it spreads, particularly among humans as our species is aware of the virus and able to take precautions. It's the least virulent variations that spread the fastest and leave immunized hosts in their wake, which then drive more virulent variations into extinction. If the evolutionary advantage was the other way around then every existing flu strain would become more and more virulent until all the hosts were extinct.
The purpose of evolution is not to create new species, but to maintain healthy ecosystems, and that explains why ecosystems are so finely tuned, and thus, easily upset by modern human activity.

This made sense to me

It's quite amazing just how blurred the facts are.....