Posted by A new* virus was recently discovered in my parents backyard, so to speak. Pop-sci articles:
Actual journal article:
A New Phlebovirus Associated with Severe Febrile Illness in Missouri
… and its NOT MY FAULT. Proof? It is apparently a new phlebovirus, and I know absolutely nothing about these guys.
The phlebovirus genome is made up of three strands of negative sense RNA— that is its genome is broken up into three parts, and backwards. It has to use a virally encoded RNA-RNA polymerase (humans do not ever make RNA from RNA, so it is not a protein this kind of virus can steal from its host) to turn its genome into the kind of RNA template that can be used to make lots and lots of viral messenger RNA, to make lots and lots of viral proteins.
Unlike retroviruses, phleboviruses do not ever have to go anywhere near the host cell nucleus. To infect a cell, the virions get endocytosed by the host cell into a vesicle, and then the viral RNA is released into the cytoplasm. And thats where all of the action occurs– generation of the RNA, generation of proteins, and assembly. Phleboviruses do not appear to want much from their host at all, except for the ribosomes.
Just to be clear, this virus is not ‘new’ in the sense we have never seen it before, or ‘new’ in the sense it has never infected humans before. Phleboviruses do infect humans, and we have known that for a long time. What is different about *this* virus, is that it is not a phlebovirus we already knew about (it is related to the others, but not similar enough that we would just give it one of the old names), and we have never seen this kind of virus in the Western hemisphere before.
And now it shows up on some farms in Missouri.
:-/
Two farmers in 2009* came down with a similar, odd illness– fever (but nothing crazy high), headache, fatigue, diarrhea, fairly standard viral fare (though also possibly an enteric bacterial infection). What was ‘weird’ for Missouri and viruses/bacteria is that they also had extremely low platelet counts and extremely low white blood cell counts. It obviously wasnt a regular ol norovirus or E. coli infection.
So they sent some blood samples off to be tested– after culturing the patient samples with some potential target cells, they found a virus. Not in the XMRV sense (they ‘found’ a virus after passaging (read: contaminating) cells over and over and over and over and then epigenetically modifying host cells to induce ERV expression), but like, they found VIRUS:
A New Phlebovirus Associated with Severe Febrile Illness in Missouri, NEJM 2012
It doesnt take the trained eye of a virologist to see there are viruses EVERYWHERE in this pic.
So these folks sequenced the genome of this virus and it turns out it is similar to phleboviruses, and as of 2011, the patients have antibodies that are highly reactive to phleboviruses. These scientists are calling this new guy ‘Heartland Virus’, and they think it is spread by tick bites. None of this is ‘proven’ yet, in the sense no one has loaded a tick full of the Heartland Virus, stuck it on some people, and waited until the people got sick, but considering the genomics, virology, and epidemiology of other phleboviruses, they are pretty sure that this is whats going on.
A nice little reminder that in a global society, zoonotic events, emerging infectious diseases, they arent just for the jungles of Asia or Africa. They can happen right here in the Heartland.
*By ‘new’ I mean that these two cases occurred in 2009, and we are just now hearing about it. ??? O.0
September 4, 2012
September 5, 2012
September 6, 2012
