There is a recurring theme in physician Robert Klitzman's book The Trembling Mountain: A Personal Account of Kuru, Cannibals, and Mad Cow Disease. When an epidemic strikes, whether in an industrialized society or in a Stone Age tribe, responses are the same: denial and a refusal to alter ingrained behaviors that are responsible for spreading the pathogen.

Klitzman gained experience with plagues after spending time in Papua New Guinea, where kuru (a rare form of encephalopathy that - like bovine spongiform encephalopathy, also known as mad cow disease - is believed to be caused by pathogenic proteins called prions) killed up to two-thirds of the population in some villages. He took a year off between college and medical school in 1981 to conduct epidemiological research for D. Carleton Gajdusek, who won a Nobel Prize for his work with kuru and a related dementia called Creutzfeldt-Jakob disease (CJD). After his fieldwork ended, the author returned to the United States to study medicine around the time when the first cases of AIDS were reported. According to Klitzman, "In all three [kuru, mad cow disease, and AIDS], people at risk feared the disease but had difficulty understanding the disease mechanisms, accepting long incubation periods, and changing deeply rooted behaviors." Among these behaviors were the eating of human flesh, the eating of beef, the practice of unsafe sex, and the use of dirty needles to inject narcotics and other drugs.

The Trembling Mountain reads like a scientific travelogue touching on the connection between kuru and mad cow disease. It also provides a slim description of a Stone Age people, the Fore. The book is not a detailed scientific treatise; rather, Klitzman aims to take readers on a journey - the same journey he took - to explore the ways in which culture molds a person's view of death and disease. This trip was Klitzman's rite of passage, during which he learned to see patients as an anthropologist sees them, rather than as a biologist might.

In the local language, the word kuru means "to tremble," a reference to the disease-induced tremors that progress until the afflicted can neither walk nor eat. As their central nervous systems degenerated, patients lost the ability to speak, were said to erupt in fits of laughter (hence its nickname "the laughing death"), and eventually died. Klitzman describes how this fatal disease spread as a result of the Fore's cannibalistic feasts. When someone died, the body was cut up, wrapped in banana leaves or a bamboo tube, steamed, and eaten. The brain - the most highly prized portion and the organ with the greatest concentration of infectious prions - was always given to the nearest female relative, who shared it with her children. Though some anthropologists claim this cannibalism never existed, Klitzman provides numerous anecdotes consistent with the practice. In one instance, an old woman approached him at a funeral to tell him that his arm would probably taste very good. In Papua New Guinea, Klitzman tracked the remaining kuru cases and observed that the infection was declining. He proceeded to determine the longest incubation period, the virulence of the infectious agent, and other factors that played a role in determining who became ill. These factors included age, genes, dose, and strain; for instance, anyone born after the practice of cannibalism ceased in 1959 did not develop kuru. At the time, researchers believed that kuru was spread primarily not by eating contaminated tissue but by touching infected mucous membranes and thereby contaminating one's hands. This made sense considering that, with no soap or tap water, women often didn't wash for weeks after a feast. It was Klitzman's job to prove that the disease was in fact spread by cannibalism.

At first, Klitzman was awkward, frightened, and frustrated as he examined dying patients and realized that he could do little more than offer them and their families a bar of soap and a blanket. He was quite naive, romanticizing Papua New Guinea as a tropical paradise and believing that the Fore would support his scientific research. Instead, he encountered problems similar to those in the West. For one thing, the people were hardly innocent. "Cultures differ in how they approach essential human needs, but the basic psychological types of individuals I encountered here [lying, materialistic, and conniving people] resembled those in New York," says Klitzman. His guides had no idea what it meant to be truthful. They had no interest in his research, working only for the money, and used him for countless favors. "The people here had no inquisitiveness into anything beyond their hamlet or personal material gain," he laments. When Klitzman mentioned the ocean on the distant horizon or that men walked on the moon, his guides were hardly interested.

Klitzman also recounts the frustrations involved in researching this deadly disease. He struggled to understand the Pidgin dialect (a combination of English, French, German, Dutch, and Malay) and to deal with chronically late guides, heat, humidity, and muddy trails. He slept with biting fleas, suffered from intestinal parasites, conducted interviews in the rain, coped with landslides, and trekked until he was exhausted. Patients bolted their doors or ran away when Klitzman visited their hamlet. Superstitious relatives refused to let him see patients, take pictures, or write down their names because they believed it would prove unhealthy. Many times he became so disgusted - especially when he went to bed hungry or was forced to eat in the mud with pigs - that he wanted to quit. At other moments, he relished the beauty and solitude of the mountain hikes and the simplicity of his life.

Despite the deaths, cannibalism continued among the Fore because they believed that kuru was caused by sorcery. They only stopped under the threat of arrest by the government. In the end, Klitzman couldn't convince them that kuru was caused by an infectious agent; the Fore wanted to see the cause, but all he could tell them was that it was too small to see. The tribe's belief in sorcery was so entrenched that even his guides, who worked with Western scientists, and teachers in the local school held these views. One local man who claimed he could cure kuru blamed his failures on patients' not following his advice. Much later, Klitzman realized that this is no different from doctors in the United States blaming patients - rather than inappropriate treatment - for their failures.

The book begins and ends with warnings about mad cow disease. People deal with disease, Klitzman asserts, by rationalizing (believing that kuru is due to sorcery or that AIDS only occurs in gay men) so that they can continue practicing long-held behaviors. The British didn't want to stop eating beef, the Fore didn't want to stop cannibalism, and people wanted to continue practicing unsafe sex. "As the AIDS pandemic spread, I saw how Western reactions resembled Stone Age responses to kuru," notes Klitzman. Some scientists believe kuru may have originated from a feast in which someone infected with CJD was eaten. CJD is now known as the disease that people contract by eating beef infected with mad cow disease. Throughout the book, Klitzman warns that although no human cases of mad cow disease have been proven in the U.S., a number of cases traced to Britain have been identified in continental Europe. Klitzman also asserts that eating beef in the U.S. may be dangerous and that the rise in the incidence of Alzheimer's disease may simply reflect a misdiagnosis of CJD.

It wasn't until mad cow disease struck that Klitzman's research was of any practical value in the West. The incredibly long incubation periods of these prion diseases struck Klitzman when he examined a patient who developed kuru 41 years after a feast. "I was sad, not just for him, but for Britain and the world. People would still die in Britain of mad cow disease more than 40 years after they ate their last infected hamburger," warns Klitzman.