Spillover: Animal Infections and the Next Human Pandemic by David Quammen

there had been second-guessing of her procedures, an investigation, questions about negligence. She had been exonerated—in fact, she made her own complaint about having not been properly warned—but it couldn’t have been helpful to her career, and that’s presumably why she wanted anonymity. She had a story to tell, yet she also wished to put it behind her.
    In the minutes after Brownie’s death, she had changed into boots, long pants, and shoulder-length gloves and begun the postmortem exam. The owners were keen to know whether Brownie had eaten some sort of poisonous grass that might threaten their other horses too. The vet sliced opened Brownie’s abdomen and found his guts looking normal. No sign of twisted bowel or other blockage that might cause colic. In the process, “I got a couple of splashes of abdominal fluid on my leg.” You can’t do a postmortem on a horse without getting smeared, she explained. Next she looked into the chest, by way of a modest incision between the fourth and fifth ribs. If it wasn’t colic it was probably cardiac trouble, she suspected, and saw that hunch immediately confirmed. “The heart was massively enlarged. The lungs were wet and full of bloody fluid and there was just fluid right through the chest cavity. So he died of congestive heart failure. That was all I could conclude. I couldn’t conclude whether it was infectious or not.” She offered to take samples for lab testing, but the owners declined. Enough information, enough expense, too bad about Brownie, and they would simply bury the carcass with a bulldozer.
    Were there bats around this property? I asked.
    “There’s bats everywhere.” Everywhere throughout northern Queensland, she meant, not just at Little Mulgrave. “If you walk out the back here, you’ll see a couple hundred bats.” The entire area of Cairns and its environs: warm climate, plenty of fruit trees, plenty of fruit-eating bats. But the subsequent inquiry turned up nothing about Brownie’s situation that seemed to have closely exposed him to bats. “They couldn’t say, other than random chance, why this particular horse got infected.” Buried beneath ten feet of dirt, having left behind no samples of blood or tissue, he couldn’t even be labeled “infected” except by later inference.
    Immediately after the postmortem, the vet washed her hands and arms thoroughly, wiped down her legs, and then went home to take a Betadine shower. She keeps a large supply of Betadine, the professional antiseptic of choice, for such occasions. She gave herself a good surgical scrub and got into bed, after a hard but not too unusual night. It wasn’t until nine or ten days later that she started feeling headachy and sick. Her doctor suspected the flu, or a cold, or maybe tonsillitis. “I get tonsillitis a lot,” she said. He gave her some antibiotics and sent her home.
    She missed a week’s work, languishing with symptoms that felt like influenza or bronchitis: mild pneumonia, sore throat, a bad cough, muscle weakness, fatigue. At one point a senior colleague asked whether she had considered the possibility that the dead horse had infected her with Hendra virus. The young vet, trained in Melbourne (way down in temperate Australia) before she moved up to tropical Cairns, had scarcely heard Hendra virus mentioned in veterinary school. It was too obscure, too new, and not an issue in the Melbourne area. Only two of the four kinds of reservoir bats range that far south, and evidently they had yet to cause concern. Now she went to the hospital for a blood test, then another, and yes indeed: She had antibodies to Hendra virus. By that time she was back on her feet, working again. She had been infected and shaken it off.
    When I met her, more than a year later, she was feeling fine, apart from a little weariness and more than a little anxiety. She knew well that the case of Mark Preston—his infection during a horse postmortem, his recovery, his interlude of