Short story about a sentient disease from a Jovian moon

Question

I'm trying to identify a hard science fiction short story I read in a hard-copy book anthology (Update: actually ClarksWorld) roughly 5 years ago. My impression is that it was a relatively new story at that time (Update: The story was about ten years old at that time).

I think it has a male western main character. He works at tracking and preventing the spread of a disease through Earth's population, although in practice that ends up looking more like the role of an armed detective. The disease is sentient, and takes over the behavior of the infected. It is only recently arrived on Earth, carried back accidentally from one of the moons of Jupiter. (The moon is named in the story, and it's one of the well-known ones, but I can't recall which moon it is.)

There is a paragraph where he imagines how the disease must have waited on that moon, through geological time, for a space-faring species to happen across it, which it could infect.

In his sleep, the MC has a recurring nightmare, of falling towards Jupiter, and the welcome oblivion of its crushing depths. But every time, before he reaches Jupiter, against all the odds, he hits that relatively tiny moon instead, where the terrible disease is waiting for him.

I think there is a (final?) scene in which the MC ends up with a gun, chasing a girl who is infected by the disease. Her words are its words.

I enjoyed the noir atmosphere, with him chasing leads, practically and with competence, but suffused with a feeling of desperate dread and inevitability.

In my memory I often conflate it with the short story "Leviathan Wept" by Daniel Abraham. I read them at the same time - although not, I think, in the same anthology. They both have a no-nonsense style, and share a (final?) scene where the male MC converses with a younger girl who represents the other.

Answer 1

This sounds like "Riding the White Bull" (2004) by Caitlín R. Kiernan. If you read it in a hardcover anthology it might have been Two Worlds and In Between: The Best of Caitlín R. Kiernan (2011). (I wonder if she's a Sisters of Mercy fan?)

Dietrich (Deet) Paine works as a freelance scrubber for the Agency, hunting down and killing (scrubbing) infected people who try to hide in the regular population.

The disease was brought back from Europa by a sample return mission, and initially caused mass outbreaks that culminated in the nuking of major cities. (Damascus is mentioned, and others are hinted at.) Subsequently the virus has tried to establish itself more stealthily, which is where the scrubbers come in.

One of the characters (Ronnie) talks about the virus waiting for them in a flashback:

“It was waiting for us, Deet,” she sobbed. “It was waiting for us all along, a million fucking years alone out there in the dark. It knew we’d come, sooner or later.”

Paine (before he gets a brain implant) has recurring nightmares of falling into Jupiter:

[...] I was falling again, tumbling silently through the darkness out beyond Ganymede, falling towards that Great Red Spot, that eternal crimson hurricane, my perfect, vortical Hell of phosphorus-stained clouds. Always praying to whatever dark Jovian gods might be watching my descent that this time I’d sail clear of the moons and the anti-cyclone’s eye would swallow me at last, dragging me down, burning me, crushing me in that vast abyss of gas and lightning and infinite pressure.

But I never made it. Not one single goddamn time.

In the penultimate scene Paine is confronting a carrier (Jet Miyake), but he fails to kill her so his handler Sarah does the deed.

Clarksworld magazine ran it in June 2015 and has it available on their website.