The Coming Plague by Laurie Garrett Read Free Book Online Page A

Some villagers in San Joaquin were downright fed up with the investigation, and the Americans became targets of wholesale theft of critical supplies, such as the diesel fuel for their generator. Things became so unstable that the Bolivian government declared martial law in the area, flying in fifty-five soldiers to maintain order. Thirty-seven of those soldiers eventually got the disease.
    The team’s work was further delayed by angry anti-American uprisings in Panama that erupted into full-scale riots, forcing closure of the Canal Zone airport and delaying return trips by Johnson, Webb, MacKenzie, and Kuns.
    One hot June day in 1964 Johnson and Webb were going over their laboratory records in Panama and noticed an odd disease pattern among the hamsters they had infected experimentally. If they injected the virus into baby hamsters, the animals almost always died and the adult hamsters would eat the bodies. The adults would then become infected at a low
level, but would survive. The adults, however, would pass on lethal infections to previously disease-free baby hamsters. How had these babies become infected?
    Johnson and Webb, now married, happily spent long hours together in the laboratory, isolating viral samples from hamster blood. There were no shortcuts, no ways to get around the long tedious hours and days of work required to get a tiny pellet of viruses from thousands of hamster cells. Once the infected animal red blood cells were grown in petri dishes, the virus had to be purified out by a series of fractionization techniques. First, they mixed the hamster cells and blood with ammonium sulfate, which created a salted-out layer of gunk that sat at the bottom of a test tube. The fluid was poured off, and the virus-contaminated mass at the bottom was mixed with an alcohol, creating another layering. The virally infected layer, now smaller and purer, was spun about at low speed in a centrifuge; objects in the test tube migrated under spin to various positions according to their weights. The garbage—extraneous bits of hamster cells—formed a visible band in the tube, which was removed. Then the tube was spun again, this time at a very high speed, adequate to separate objects that differed only slightly in weight.
    A pellet would be left, at long last, at the tube’s bottom—a nearly pure sample of concentrated, deadly Machupo viruses.
    Johnson and Webb discovered that the adult hamsters were shedding virus in their urine. They then bred wild mice from San Joaquin and found the same thing—the animals actively urinated Machupo virus. The baby rodents had become infected because they were caged in an atmosphere of wood chips and sawdust drenched in Machupo virus.
    Johnson felt the archetypical cartoon lightbulb flash above his head and heard himself shout, “Aha!”
    He returned to San Joaquin and did a very simple experiment: He divided the town in half. On one side he set five-cent mousetraps throughout houses and corn storage areas. The other half of San Joaquin was left alone. One woman living in the trap side of town begged Kuns to give her as many traps as possible; he could only spare three. In a single night she caught twenty-two mice in her home, proudly presenting them all to an astonished Kuns the following morning.
    Within two weeks the difference was obvious. While the epidemic continued at the same pace on one side of town, no new Machupo virus cases occurred where mousetraps had been set. Two weeks later, having set traps throughout San Joaquin, Johnson’s team stopped the Machupo epidemic.
    â€œThis is unbelievable,” Johnson proudly said to himself. “Within just eighteen months we isolated the virus, discovered its mechanism of transmission, and stopped it cold.”
    Between 1962 and 1964 over 40 percent of the residents of the San Joaquin region were sick with Machupo virus; some 10 to 20 percent of the villagers died of the disease. If the region hadn’t