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

been so sparsely
populated, the impact could have been devastating. As it was, for the people of San Joaquin, Magdalena, and the surrounding area, Machupo virus was a scourge that claimed at least one member of every family and was carried aboard mouse-infested supply carts to remote parts of the eastern frontier. Its impact on people’s lives would not soon be forgotten.
    Over the next three years the Panama-based researchers would fill in some of the remaining pieces of the Machupo puzzle, and successfully stop a second outbreak of the disease deeper in the Bolivian savannas. 5
    Johnson put together a best-guess history of Machupo virus, and together with MacKenzie, Kuns, and Webb published several scientific papers between 1964 and 1966 describing most aspects of the virus. He decided the epidemic’s roots lay in Bolivia’s social revolution of 1952, when the people of the San Joaquin area suddenly found themselves without an employer or steady source of food supplies. In their haste to grow corn and other vegetables, they chopped down dense jungle areas of the alturas and bandas wherever the land naturally formed a relatively flat mesa above the Machupo River flood line. In so doing, they unwittingly disrupted the natural habitat of the Calomys field mouse and provided the rodent with a superior new food source: corn.
    The mouse population swelled during the 1950s and the rodents literally invaded the town of San Joaquin in the early 1960s.
    By the time the first cases of Bolivian hemorrhagic fever (as the disease was now dubbed) surfaced, the mice could be found anyplace the townspeople stored food and grain.
    And each night while the mice nibbled away at the humans’ food supplies, they urinated.
    The virus could be eaten or inhaled or could gain entry through cuts in the skin; in any event, Machupo could be lethal.
    Johnson noticed that there was a ritual common to every household in San Joaquin. Before dawn the mothers and grandmothers would awaken and quietly prepare breakfast for the men and children. While pots boiled, the women would sweep their dirt and clay floors.
    â€œAnd each time they sweep that broom,” Johnson realized, “they’re sending mouse urine-infected dust and crumbs drifting all about in the air.” Every time the families of San Joaquin assembled for breakfast, they shared virus-contaminated air. Johnson also decided that he, Ron, and Angel got sick as a result of eating contaminated food at the San Joaquin party.
    Researchers from the Rockefeller Foundation Laboratories in New York City and the University of Buenos Aires eventually reached a similar set of conclusions about the Argentine Junin virus. An Argentine team led by Dr. A. S. Parodi concluded that another species of wild Calomys mouse had been flushed out of its pampas habitat by post-World War II changes in local agricultural practices. Farmers had long had difficulty growing profitable crops of corn because short broad-leafed weeds had invaded the
fields. After World War II, herbicides effectively eliminated the short grasses and dramatically increased crop yields. 6
    As harvest time approached, however, taller grasses that were not affected by herbicides would grow in the corn fields, thriving just when humans entered the fields to reap the corn. As it turned out, a fairly rare species of field mouse naturally subsisted on the seeds of these tall grasses. As the grasses proliferated, so did the mice, until the once-rare species became the dominant rodent of the region.
    The mouse, of course, carried Junin virus, the cause of Argentine hemorrhagic fever. 7
    MacKenzie thought another Bolivian factor also played a role in the San Joaquin epidemic. On all his trips to Magdalena, Orobayaya, and San Joaquin, he was struck by the remarkable absence of cats in the villages. When he asked the people what had happened to the cats, he was told they all died.
    The feline die-off coincided with the rise in the