A Local Life: John Cross, 85; parasitologist solved mysterious illness in the Philippines
Saturday, December 25, 2010; 6:47 PM
People began dying by the dozens in little coastal villages in the Philippines in the 1960s, and no one knew why. Some suspected a curse and hired two witch doctors to exorcise the area. The two toiled until one of them died of the very illness they were trying to drive out.
John Cross, a civilian parasitologist leading the U.S. Navy's efforts to prevent outbreaks of tropical diseases by understanding parasites' ecology and biology, sent two scientists to find out what was going on.
They quickly discovered that the villagers were suffering from acute infections of a worm that caused extraordinary diarrhea, emaciation and death. But it was years before anyone could say with certainty how the villagers had been infected and how the spread of disease could be stopped.
Dr. Cross, the sleuth who eventually solved that mystery with a combination of creative experimentation and stubborn endurance, died Nov. 19 of complications from diabetes at Shady Grove Adventist Hospital in Rockville. He was 85.
He had taught since 1984 at the Uniformed Services University of the Health Sciences in Bethesda, where he was admired by medical students for his engaging lectures highlighted by photographs and stories from more than two decades of studying tropical diseases in Asia.
The litany of diseases he studied included schistosomiasis, malaria and the plague. He was perhaps best known for his work on the mysterious, cholera-like illness that attacked Filipino villagers on the island of Luzon in the 1960s and has since appeared in Thailand, Iran and Egypt.
At the time of the outbreak, the worm that caused the illness was new to science and its life cycle was not understood. Capillaria philippinensis was first identified in 1964.
Navy scientists suspected that villagers, whose diet consisted of raw fish and shrimp, were ingesting the Capillaria worms with their food. But the scientists, working in a makeshift hospital and laboratory powered by a Honda generator, could not find evidence to show what other animals harbored the worm or how it was being delivered to villagers' intestines.
"We went through 30,000 necropsies, everything from shrimp and little fish to cattle and sheep, and we never could find anything," said K. Darwin Murrell, who was a young Navy parasitologist working under Dr. Cross at the time. "We were really puzzled."
After more than a year of that tedious work, Murrell was transferred back to the United States. He doubted that anyone would ever untangle the Capillaria outbreak, and he began to believe it was a freak occurrence that posed no enduring threat.
"I remember telling John I thought it was senseless to try to continue to do necropsies on everything under the sun down there, that this was an ephemeral event and we probably wouldn't see it again," Murrell said. "I could see he was skeptical of that."
Dr. Cross took his efforts into a laboratory, where he began a painstaking process of trying to infect various animals with the Capillaria eggs.