Wednesday, October 1, 2014

Why I Am Less Fearful About Ebola Than I Used To Be

Ebola is a hemorrhagic fever.  It turns that mant Americans (at least those of European ancestry) are likely immune to it, because so many of us have the CCR5-delta 32 mutation, which protects from HIV and hemorhhagic fevers.  Even if it were to break into the general population, the net effect would be to disproportionately kill the poorest and most reliably Democratic voters.  Since many Americans have already been exposed to HIV (especially in the 1980s through blood transfusions) without developing AIDS, my guess is that the risks of getting Ebola are relatvely lower than for the unlucky people of West Africa.  Our ancestors in Europe paid the price during the Black Death, thank them for their sacrifice.

7 comments:

Jeff Dege said...

The article states that 10% of the population carries the gene. That's not enough to prevent an epidemic.

Jeff Dege said...

Following up - I've found other articles that claim that up to 20% of western europeans carry the mutation. But if you look at the data for other infectious diseases, you need an 80-90% immunization rate before you observe a herd effect that essentially prevents a disease from becoming an epidemic.

Clayton Cramer said...

10% won't prevent an epidemic, but it will slow it down.

Tom Bridgeland said...

It's about 20% of Scandinavians and Scots, decreasing as you get farther away.
Clayton, that is rather more cold-blooded than I like. I wish Democrats would vote a lot less, and stop moving out of states they have ruined, nothing worse.

Richard said...

Well, it wasn't Clayton but President Obala that wouldn't do the screening.

StormCchaser said...

What will stop an epidemic is the fact the we are mostly a first world nation. Even Nigeria stopped an outbreak recently by just doing a few things.

That genetic is just the tiniest of factors protecting us, and is not enough to make a dent in the epidemic.

Consider AIDS, which is spread similarly to Ebola (although Ebola spreads somewhat easier - but in either case we are talking bodily fluids). It spread almost completely due to poor hygiene (causing hemophiliacs to be killed as the result of irresponsible behavior of others). But, it didn't get loose in the general population for the same reason Ebola wont.

hga said...

After looking at a couple of papers, one of which might have said it doesn't appear that this mutation would provide help with Ebola, I noted one inherent issue: the protective mutation is necessarily recessive.

If you have only one copy of the mutation, that is, you're heterozygous, the other, normal one will produce half of the CCR5 proteins in cells, and a virus will get in through those. One paper seemed to imply that being homozygous for this mutation was rare.