Infectious Diseases: Casualties in a Jungle War

Twice last week the big U.S. Air Force hospital plane thundered north from La Paz to the Canal Zone, each time carrying strictly quarantined, desperately ill patients plucked from the hinterlands of Bolivia for transfer to the modern facilities of Gorgas Hospital. First to land were Wisconsin-born Dr.Ronald MacKenzie, 38, and Panamanian Technician Angel Muñoz, 42. At Gorgas, the fearful diagnosis made in the field was confirmed: both were victims of a newly discovered and deadly disease, Bolivian hemorrhagic fever. By midweek, the C-130 with its doctor-nurse team had made another trip, carrying New Jersey-born Virologist Karl Johnson, 34. He also had the fever.

The illnesses of these men recalled the stirring days of Walter Reed’s famous campaign against yellow fever in Cuba at the turn of the century, when one researcher died and others had close calls. For the two physicians and the technician had been working selflessly, at great risk, in an internationally supported crash program to pinpoint the cause of a mysterious disease, and to find a preventive for it.

As Cold as Marble. When the fever began its rampages three years ago in Bolivia’s northeastern province of Beni, the dirt-poor villagers around San Joaquin called it “the black typhus.” But this was a far deadlier disease. It struck almost one-third of the population, and killed about one-third of its victims. Men and women of all ages were stricken. First came fever, chills and headache. Then, in many cases, an agonizing pain in the back, usually followed by a rash in the throat, tremor of the tongue and extremities, bleeding from tiny vessels around the eyes, and blood in the urine. After about a week, many of the victims turned as cold as a morgue slab before they died. Survivors presented a pitiable sight for weeks, with bleeding gums and persistent tremor, and often in a state of delirium or stupor.

Bolivian doctors concluded that the disease was a form of hemorrhagic fever similar to those already known from Manchuria, Korea, India and Argentina. But was the responsible virus the same as any of those from other lands? And what animal or insect transmitted the virus to its human victims? Bolivia asked the internationally sponsored Middle America Research Unit, based in Balboa with Arizona-born Dr. Henry K. Beye as its head, to mobilize its forces for a jungle war.

From Caribbean bases, the U.S. Air Force flew ten tons of supplies to Bolivia in March, and four tons of laboratory gear in May. The Bolivian air force flew it all to San Joaquin. There, a team of physicians, virologists, entomologists, and ecologists set to work. First, the disease detectives plotted where the fever victims had lived—and died. They put healthy monkeys in single cages and left them for days in the forest where four woodcutters had . I worked just before they became ill. They put other “sentinel” monkeys in houses left empty by the deaths of whole families of fever victims.

Louse Hunt. Their sentinel duty over, the monkeys were examined to see whether they had caught the disease, and what kind of parasites they had picked up. The doctors directed the trapping, snaring, netting or shooting of specimens of every living thing that could conceivably carry the virus. The only local people hired to help were those who had already had the fever and recovered, and therefore, presumably, were immune. The M.A.R.U. technicians examined suspect animals and picked off their parasites, through armholes and sleeves in Isolettes, with less than normal air pressure inside to guard against infection by airborne viruses. Comparable precautions were taken in drawing blood samples from fever patients and by pathologists in performing autopsies.

A month ago, Virologist Johnson was elated. From the liver and spleen of a three-year-old boy who had died of the fever, his team had isolated what was almost certainly the virus. Stored in liquid nitrogen at — 350°F., the samples were flown to the Canal Zone and to the U.S. Laboratory of Tropical Virology at Bethesda, Md. The virus, the experts at these research centers concluded, was similar but not identical to the one that causes hemorrhagic fever in Argentina.

A week later, determined to find the parasite that carries the virus to man, Dr. MacKenzie teamed up with Dr. Johnson and Technician Munoz in a new and daring technique. They dragged strips of cloth through the yards and bushes around houses where victims had lived, in hopes of catching hungry lice and ticks. Fortnight ago, MacKenzie and Munoz developed the telltale fever, headache and muscle pains. A quick check by their colleagues showed a typical drop in their white-blood-cell counts. Dr. Beye, back in the Canal Zone, ordered them flown to Gorgas Hospital. There, though there is no specific antidote for the virus, they could get the best possible care.

The only time the three had taken a common risk was during the parasite hunt on June 26. Almost certainly, the carrier of the virus is among the mites and lice they caught that day. Said Dr. Johnson feebly but hopefully from his sickbed: “I feel the carrier is literally in the bag.”