Andrew Roberts asked:
In regard of STDs – sexually transmitted infections – is it possible that virus strains, or types can combine in a host, say a human, and create a more destructive dangerous or communicable super virus?
Estee - Absolutely. I mean, so there was a case report I think in the New England Journal of Medicine a few years ago of exactly that - a man who presented with HIV infection and then was subsequently re-infected with another strain and had a faster disease progression and died in fact.
Chris - Because once you've got one strain, if you add another one on top then they can share genes between the viruses and you end up with a virus that's got all of the worst bits of both.
Estee - Absolutely.
The only thing most STDs have in common is they need certain conditions to get from one person to the next. They dry up and die easily, for example, and need to be transfered from one warm, wet mucous membrane to another immediately. You will not catch it shaking hands or touching a door knob. Or STDs live inside cells found in certain bodily fluids. But genetically, an organism like chlamydia is very different from the bacteria that causes gonorrhea or a virus like HPV or AIDs, and I would think it would be unlikely they could combine in anyway. That said, I have read that being infected with one STD increases the chances of getting infected or transmitting a second one if it is also present, and I think it has to do with the inflammatory conditions (more fluid, open sores) of the affected area. cheryl j, Mon, 9th Jan 2012
Bacteria can also swap DNA via Plasmids, or even pick up environmental DNA.
Couple days ago I saw a TV-program on discovery exactly about it. Viruses can change - for instance, chlamydia testing shows that during 50 years symptoms have changed, and thus the virus is also mutated Michaella, Mon, 18th Jun 2012