Sector C (18 page)

 
“A new disease.”
The strain in Donna’s voice made it sound brittle, on the verge of breaking. “That’s why I kept coming up empty. When the lab said it wasn’t BSE, I thought maybe we’d have a chance to control it if we could just identify it. But if it’s prionic like BSE or scrapie, we won’t be able to treat it. Not with any degree of certainty. Not in animals — and not in people.”

“So theoretically I know what diseases like BSE and CJD are and what they can do,” Mike said.
“At least from a layman’s view.
But how do they work? Prions aren’t like bacteria and viruses, right?”

“Prions aren’t alive like bacteria and viruses, no. They’re just bits of protein — a few amino acids strung together and folded in a way that somehow helps neurons transmit signals, mainly in the brain. And since they aren’t alive, you can’t kill them
per se
. You have to destroy or denature them. We all have normal prions in our bodies and apparently we need and use them as long as they behave themselves. But when they mutate, the result is kind of like how cancer spreads. Only instead of
new
cells being formed that are cancerous, which is how cancer grows, the existing prions can become misshapen because of a chromosomal, or genetic, trigger. Or you can eat something that has a lot of these mutant prions and a few could make their way into your body through the bloodstream and infect the normal prions you already have, turning them into diseased bits. The diseased prions then attack the nervous system and you wind up with a brain that’s so eaten away it looks like a sponge. Basically, Bovine Spongiform Encephalopathy is just a snooty way of saying ‘spongy cow brain’.

“Or mad cow disease.”

“Which pretty well sums up what lots of microscopic holes in the brain will do to a cow — or a
person.
But that’s too visceral a term for science. So they dress it up in Latin and take the passion out of medicine.

“Usually, though, it takes a long time — years in cattle, sometimes decades in people — before a prionic disease progresses to the point where it swiss-cheeses your brain and kills you. Or builds up enough plaque in your brain you can’t remember your own name. We generally don’t even test cattle younger than two-and-a-half years old for BSE because the disease is so slow. Prion disease in children is practically unheard of. But if it’s a new strain …”

 “Didn’t you test for prion diseases?”

“Of course I tested for scrapie and BSE. There’s a quick-test for each of them that’s been on the market for about five years. Mix a little spinal fluid with the testing reagent and if those types of prions are present, they glob onto the reagent and precipitate out, leaving a residue at the bottom of your test tube. We can get a preliminary verification in the field in about 30 minutes. We still send all positives to the lab to confirm, though, and those tests take weeks as they actually grow out the samples in mice.

“But our field results were negative. Or at best inconclusive. There was a trace of residue in some samples but that could have been caused by contamination of some kind. You also have to understand that the tests are protein-specific. The test for BSE won’t pick up scrapie and vice versa. Given the symptoms, I couldn’t chance ruling out a diagnosis on the quick-tests alone, which is why I sent samples to the lab anyway.”

“OK, then if we look at the known prion diseases, what do they have in common? People can get mad cow disease from infected beef. Can most mutated prions jump species?”   

Donna frowned. All those years of classroom study seemed to slip away the farther removed she was from the rigor of university life. Out here, she had pretty much fallen into a routine of seasons and diseases. Hers was a life of vaccinating, castrating, worming and dosing with preventives to keep diseases from surfacing. Occasionally a horse wound itself up in barbed wire or a dog got itself snake bit or a goat got attacked by a coyote and she had to pull out the usual antibiotics or steroids to cope. And there was the usual run of breached babies and mastitis in the spring, and West Nile and tick-borne Erlichiosis to handle in the summer. That was about as exotic as medicine got in an area where a good many of her patients never made it into old age.

But there was something about BSE and Mike’s question that seemed relevant. Random googling would probably jar her memory; it was just frustrating that she couldn’t put the pieces together without resorting to the internet. A memory of a conversation dredged itself up from the recesses of her cortex. It seemed random yet important somehow. “Bear with me here. I’m thinking out loud. One of the ranchers found tracks around a dead calf six, maybe seven weeks ago, not long after we began seeing symptoms. I’d almost forgotten that call. He wanted us to notify the ranchers that there was a cat on the loose. A cougar, we thought.”

And then it struck her, what she’d been trying to see all along. “Damn.
FSE.”

“What?”

“FSE —
feline
spongiform encepalopathy.
Domestic cats can get a variant of mad cow. And if domestic cats can get it, maybe their larger cousins can, too …” It was the piece she’d been looking for ever since their visit to Triple E.

“The tiger.”
Mike blanched.

“Coincidence
that animals
started getting sick around the same time their tiger escaped?”

“But don’t you have to eat part of an infected animal first to get sick?”

“That’s the classic transmission route.
For BSE.
But even then, mutated prions can be found throughout the animal. In its muscle, in its milk —” she looked pointedly at Mike, “— in its urine. The prions just aren’t as concentrated in other parts of the body as they are in the nervous system. But maybe these new prions do concentrate elsewhere. If an animal grazed over an area where the cat peed …”

Mike worked out the logic trail. “Then if that animal got the disease and began spreading it through its urine in an area where other cattle were grazing, you could get a whole herd infected. And then mother cows would pass it through their milk to their calves — or into the milk shipped to the stores.”

“And if it’s in the urine, it could well be in the saliva, too. After the cat killed a calf and ate its fill, coyotes would likely clean up after it. If they became infected, they would start spreading the disease as well. Hell, for that matter, rats and mice and buzzards could pick it up from carrion and become carriers, too. Who knows how many species are involved? Is it even limited to mammals?”

“My God.
We could slaughter every head of cattle in the state and still not stop it, if that’s the case.”

“Something like that would be impossible to prevent if it gets into the migratory bird population. Every place a flock roosted would become a hot zone.”

“We need proof of its transmission route.” The implications of how farspread this disease could become was chilling. This wasn’t a simple case of containing an outbreak of
Pneumococcus
or psittacosis. This was turning into a potential pandemic that could eradicate a large portion of the human and animal populations in the western hemisphere. Maybe —
maybe
— it could be contained to North and South America if travel and shipping quarantines were established quickly enough. Aside from the Bering Strait, were there any other points that land animals or birds could easily cross the Atlantic or Pacific? Was Hawaii safe?
Or the Bahamas?
Cuba was likely in the migration path of some variety of bird. Getting confirmation as to whether the disease was avian borne would have to be the first priority for the CDC labs. Mike’s first priority, meanwhile, given his lack of any helpful medical knowledge beyond some rudimentary principles was identifying Patient Zero, if possible. And for that, he had a pretty good clue. “Didn’t you say you still have the tiger’s head?”

“In a bag in the freezer.
Yes. I’ll do quick-tests for BSE and scrapie both, but I’m not sure how reliable the tests will be after the amount of decomposition it had outside in the sun and the time since that it’s been frozen. Same goes for a necropsy. In classic BSE, the entire brain would be so deteriorated at the time of death there wouldn’t be much question about the diagnosis. But this new disease seems to localize the degeneration, which is why it’s been missed. I’ll just take the back of the head and part of the brain stem to look at here and send the rest to the lab. I’ve been using the vet lab at NDSU, but I could split the head and send half to the university and the other half to the CDC if you want your teams involved.”

While Mike queried the ZVED teams on how to proceed, Donna placed a perforated stainless steel board over the tub in the kennel area, removed the head from the freezer and laid it on the board. Mike reached out to touch the frozen fur. “It’s bigger than I thought it would be.”

“It was male and a young adult by the condition of its teeth. Fully grown, I presume.
Probably weighed around 400 pounds.”

“I thought you said it was a white tiger. I didn’t expect the stripes to be so prominent.”

“In tiger lingo, the color refers to the base coat, not to the stripes. Most tigers have an orange base coat with black stripes. This one has a white base coat with dark brown stripes. A black tiger — which is really, really rare — has a black base coat with orange stripes.” She fetched a sonic bone saw from the surgery cabinet and sliced off a two-inch thick piece of skull from the base of the head where coyotes had made a neat separation between the first and second vertebra, working quickly so the head wouldn’t start thawing in the warm room.

“ZVED says send it all to the university since they know what to look for now. In fact, they’re sending a team to Fargo to take another look at the milk and tissue samples from the herds that you sent earlier.”

“Will that really matter?” Donna repackaged the tiger’s head and placed it back in the freezer.

Mike sighed.
“Probably not.”
Donna looked at him. “OK, no. It won’t matter. You and your colleagues will be getting phone calls soon. I’m just waiting to see when the alarm will be tripped. It could be as early as tonight, certainly by tomorrow morning.”

The vet slumped into a chair.
“My God.
It’s really come to this, hasn’t it?”

“I’m sorry.” Mike placed an awkward hand on her
shoulder,
half afraid she would reject the contact. When she didn’t, he knelt down beside her. It was one thing to remotely monitor the activities and the amazing amount of coordination going on among a dozen different teams spread across the country. It was the war-game syndrome. Those in authority had to make objective decisions and to do that effectively had to remove
themselves
emotionally from the game. Concentrating on feeds and statistics and generalized reports made it easy to keep that distance from the very real consequences of those decisions.

But that was his world, not hers. Hers was the world where coworkers were dying and animals she’d been working tirelessly to keep healthy were about to be slaughtered — each and every one. Hers was the world where she would be left to deal with the very real aftermath long after he’d packed his bags and returned to Atlanta. Hers was a world he could only begin to understand. And hers was a pain he could only begin to touch.

He slid his hand into hers. “You won’t have to be involved. Homeland Security is already mobilizing the National Guard.” He thumbed his phone for information. “There’s an Armory in Williston. Once the trigger is pulled, they’ll be out in a matter of hours.”

“Just here?”

“No.
Looks like the CDC is ready to declare a state of emergency throughout North Dakota, South Dakota and Montana.”

Donna tried to keep focused. “What exactly does that mean — state of emergency?”

“First there’ll be a lockdown on all transportation of livestock in and out of the region. They’ll shut down all food processing plants that handle meat or milk. Won’t matter if it’s for human consumption or not. I don’t know if they’ve determined yet whether people can spread the disease, but if they can, then the airports, train stations and bus stations will probably be closed. Guardsmen will be stationed on all major roads at state borders. Most of the Guardsmen will do a sweep of the states, looking for target animals. They’ll be the ones who’ll talk to the ranchers. They’ll be the ones who’ll —” he fumbled, knowing there was no easy way to say it, “— who’ll put the herds down.” He felt her hand tighten around his.

“No matter where or how it started, it’s out of our hands now.” That was the best comfort Mike knew to give her. “But if that tiger is Patient Zero, I’m damned if I’m going to let Triple E duck its responsibility on this. The general order will only be for commercial food animals, so the Guard won’t have reason to pursue their operation. But once the feds declare an emergency, as a member of the CDC task force I won’t need a warrant to see their animals if I have reasonable cause for suspicion.”