darcoda at telerama.lm.com (S. Frog) wrote:
>>> Hi, and all that.
>> I'm not sure if this is the proper place to raise this question,
> and forgive me if it isn't, but I have a question about the flu.
> Actually, three questions:
> Is the flu a retrovirus?
> If it isn't a retrovirus, do I have a faulty definition of what a
> retrovirus is?
> Lastly, is it true that the flu has only been around for like a
> hunred years or so? And that it mutated from something else, which is
> why human has so little resistence to it when the influenza epidemic
> roared through just after world war I?
>>> Thanks. :)
>>>>> S. Frog
The agent which causes many cases of the "flu" is called influenza. It
is a member of the Orthomyxoviridae. These viruses have a segmented, single
stranded RNA genome. Their segmented genome enables them to undergo a special
kind of mutation (actually it is segment reassortment) called antigenic shift,
which causes the pandemics in human medicine. Many species have their
own flu virus. Horses, pigs, and birds are some examples. Influenza is mostly
a respiratory virus, which means if you have diarrhea and vomitting, you don't
have the flu, you have food poisoning.
Influenza is not a retrovirus. Retroviruses (Retroviridae) have an RNA genome, but
convert the RNA to DNA within the cell with reverse transcriptase (hence their name).
Retroviruses do not have multiple RNA segments, like Orthomyxoviruses, but do have 2
copies of their RNA within their capsid.