to the basement himself, chloroformed all the remaining parrots, chloroformed the guinea pigs and pigeons and monkeys and rats involved in the same experimental work, and threw their dead bodies into the incinerator. This forthright man, this hands-on administrator, described in one source as “tall with a gnarled Lincolnian face,” was Dr. George W. McCoy. For reasons explicable only in terms of the wonders of the immune system and the vagaries of fortune, Dr. McCoy didn’t get sick.
The psittacosis epidemic of 1930 was winding down, and probably also, though more slowly, the psittacine panic. On March 19, the Acting Secretary of the Navy issued a general order for sailors on shipboard to get rid of their parrots. George McCoy reopened the Hygienic Laboratory, Charles Armstrong returned from convalescence, and the search for a cause of the disease continued.
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Within a month, a culprit had been identified. It was a small bacterium with some unusual properties, seemingly similar to the agent that causes typhus (Rickettsia prowazekii) and therefore given the name Rickettsia psittaci. Where did it come from? Argentina had been implicated as a source of sick birds at the start of the 1930 outbreak; President Hoover’s embargo would have stanched that source. But then latent psittacosis was detected in some commercial California aviaries, where parakeets for the domestic pet trade were produced—meaning that American breeders were harboring an endemic reservoir of the infection and distributing it by way of interstate commerce. So a proposal was made to destroy all those infected flocks and then reestablish the trade with healthy birds from Australia. This seemed to make sense on two counts. First, what we Americans call a “parakeet” is a native Australian bird, widespread and abundant in the wild, known to Australians as the budgerigar. Second, Australia itself (despite a high diversity of psittacine birds) was thought to be psittacosis-free. Starting over with wild birds might free the American bird trade of psittacosis. That was the idea, anyway.
A pair of American scientists got permission, despite the embargo, to import a consignment of two hundred Australian parakeets lately captured in the vicinity of Adelaide. They wanted to do an experiment. Their plan was to infect the imported birds, whose immune systems were assumed to be naïve, with American strains of psittacosis. But when one of the imports fell dead, not long after arrival, the scientists opened it up and found Rickettsia psittaci. They also noticed that some others of their birds, seemingly healthy, carried the bacterium as a latent infection, like the birds in those California aviaries. That raised fresh concern about what might be lurking in other aviaries, in zoos, and in pet shops around America, and strongly suggested that Australia might not be as clean as it seemed.
This is where Frank Macfarlane Burnet, a great figure in Australian science, enters the story. Burnet was a complicated, brilliant, crotchety man and a signal character in the study of infectious diseases. Eventually he would earn a knighthood, a Nobel Prize, and a number of other fancy honors, but long before those he had made a name for himself in zoonoses. Born in 1899, second child among an eventual seven, he was a solitary, opinionated schoolboy who read H. G. Wells, disapproved of his own father’s shallow morality, preferred beetle collecting to more sociable activities, despised his roommates, read about Charles Darwin (who became one of his heroes) in an encyclopedia, forced himself (despite an inaptitude for sports) to achieve competence as a cricketer, and became an agnostic during his undergraduate years. Unfit for a career in the Church, ambivalent toward the law, he chose medicine. He trained as a doctor in Melbourne but then, recognizing his lack of empathy with patients, went to London for a PhD in virology. Declining a chair at the University of London, he returned to Australia to do research. He was a nationalist, stoutly Aussie. Much later in life, laden with honors and fame, Burnet kept his edge by publishing cranky pontifications on a wide range of subjects including euthanasia, infanticide for handicapped babies, Aboriginal land rights, population control, tobacco advertising, French nuclear testing in the Pacific, the futility of trying to cure cancer, and the merits (low, in his view) of molecular biology (as distinct from his discipline, microbiology). Burnet received his Nobel, in 1960, for helping illuminate the mechanisms of acquired immune tolerance. His role in understanding zoonotic diseases began much earlier. In 1934, as a young microbiologist based at the Walter and Eliza Hall Institute,