Krdytkyu

I'm trying to identify a story - I think it was novella, not a short story, but I'm not sure - about people who survived when a disease wiped out most of Earth's population.

If I recall correctly, the surviving people were living in domes, because the disease was still in the air. Some people were resistant to the disease, because of some difference in their DNA - I seem to recall it being described as "backwards".

These people with the "backwards" DNA then leave the domes - I don't remember why - ending up in Egypt, I think. Around this point in the story I remember the disease being described as acting so quickly that you could get a headache, lie down for a rest, and a couple hours later be nothing but dust.

I read this in the past two years, but I think it was older than that. If I recall correctly, it was in an anthology of selected stories - the year 1995 comes to mind. It was not a tall book, and I think the cover was dark. IIRC, it was a collection of stories by different authors.

For White Hill by Joe Haldemann. I read it in The Hard SF Renaissance edited by David G. Hartwell and Kathryn Cramer. This anthology was published in 2002, but the story dates from 1995 and you presumably read it in one of the earlier anthologies.

After a war the Earth has been seeded with nanophages. These kill people in the way you remembered:

There were fewer than ten thousand people living on the blighted planet then, an odd mix of politicians, religious extremists, and academics, mostly. Almost all of them under glass. Tourists flowed through the domed-over ruins, but not many stayed long. The planet was still very dangerous over all of its unprotected surface, since the Fwndyri had thoroughly seeded it with nanophages. Those were submicroscopic constructs that sought out concentrations of human DNA. Once under the skin, they would reproduce at a geometric rate, deconstructing the body, cell by cell, building new nanophages. A person might complain of a headache and lie down, and a few hours later there would be nothing but a dry skeleton, lying in dust. When the humans were all dead, they mutated and went after DNA in general, and sterilized the world.

The protagonist is immune because:

White Hill and I were "bred" for immunity to the nanophages. Our DNA winds backwards, as was the case with many people born or created after that stage of the war. So we could actually go through the elaborate airlocks and step out onto the blasted surface unprotected.