Cuba’s Epidemic: Doctors Know What It’s Not

So far, doctors know what the disease is not. Health specialists from around the world agree that a mysterious nervous-system epidemic that has swept across Cuba is not caused by a virus and not by bacteria.

Although the eye and limb disease has stricken about 45,000 Cubans since it appeared on the island 1 1/2 years ago, doctors say it is not contagious. It does not spread through households, boarding schools and military barracks as a contagious disease would.

Poor diet and vitamin deficiencies--a consequence of the country’s prolonged economic crisis--have made Cubans an easy host to the disease that causes a loss of vision and pain or numbness in the limbs.

But malnutrition apparently is not the cause. “A vitamin deficiency exists and plays a permissive role,” said Dr. Benjamin Caballero, a nutrition expert and professor of international health at Johns Hopkins University in Baltimore. “But that’s not what this is. This is not the Warsaw Ghetto or a POW camp. It is not Haiti or Bolivia.”

Caballero, like many American, European and Latin American doctors who have visited Cuba and studied the epidemic in recent months, says he believes the disease is caused by prolonged exposure to a “toxic agent.” But experts have yet to figure out which one might be responsible.

Amid the economic deterioration and stepped-up rationing, Cubans increasingly have taken to making their own consumer goods--rum, hygiene products and health remedies that could have toxic ingredients. As meat, milk, eggs and some vegetables became scarce, many people substituted foods such as soy or cassava root, a carrier of natural cyanide.

Jorge Antelo, a Cuban deputy health minister, said government and foreign doctors have examined more than 100 possible toxic agents, including cyanide and methanol, which is used in home-brews of rum. None of the tests has been conclusive. “It’s still too soon to say what specific agent might be the cause,” Antelo said.

Caballero said he is “skeptical of finally finding something. It may be that we never identify anything categorically,” he said.

The epidemic of what is described as optic neuropathy or peripheral neuropathy has peaked, doctors say, in part because of the natural rhythm of epidemics and, in part, because the government began massively distributing vitamins last month to help Cubans resist falling ill.

While the total number of cases continues to rise, the number of new cases each week has dropped to about 20% of what it was in April and May.

“As a crisis, I think we have turned the corner, even though the numbers keep going up,” said Dr. Alfredo Sadun, professor of ophthalmology at USC Medical School.

Sadun visited Cuba in May with a delegation from Orbis International, a nonprofit organization that fights blindness. The Pan American Health Organization invited another delegation of American doctors from Johns Hopkins and the National Institutes of Health in Bethesda, Md., to examine patients.

The disease is not known to have caused any deaths. It has not spread to tourists or beyond the island. Since it is not contagious, doctors say it is “very unlikely” the disease would spread to Miami, 190 miles from Cuba, or other parts of the United States.

Victims of the neuropathy suffer sudden blurriness or loss of color vision, tingling, pain or a loss of feeling in the hands and feet. They may also suffer weight loss, dizziness and headaches. In most cases, the symptoms last four to six weeks and there is no long-term damage to nerves. Doctors estimate that 2% to 10% of the victims may be left with some permanent loss of sight or coordination.

Patients are hospitalized for 21 or so days and treated with injections of high doses of vitamins. In some cases they are given drugs or exotic treatments such as ultrasonic and magnetic therapies.

Josefina de Camacho, 46, a bank employee from the eastern city of Santiago de Cuba, said she was treated in the hospital with vitamins, a glucose hydration fluid and interferon. “I am feeling better. I began to regain the feeling in my hands and feet a couple of weeks out of the hospital, although my doctor has warned me that total recovery could be slow, that it could take up to a year,” she said.

The disease first surfaced in western Cuba in late 1991, primarily among male adults, and spread slowly. Only 300 cases had been reported by the end of 1992. But this year the disease took off across the island and among other sectors of the population. By May 1, the Health Ministry was reporting 26,000 cases. Last week, Antelo put the figure at 43,000 cases and the Pan American Health Organization representative in Cuba, Dr. Miguel Angel Marquez, reported about 45,000 cases.

Despite an American trade embargo imposed in 1960, Communist-led Cuba was once hailed as one of the healthiest, best-fed countries in Latin America, with the lowest infant mortality rate in the region. Under President Fidel Castro, the country developed an impressive, free health-care system and medical research industry.

But living standards have plummeted since the collapse of the Soviet Bloc in 1989, when the vast majority of Cuba’s trade was with its Communist allies at preferential prices. The Cuban economy has been reduced to half the size it was four years ago and Cubans face severe rationing and daily shortages of fuel, food, medicines and clothing.

The critical situation was further compounded by tropical storms in March that destroyed housing and key crops and interrupted tourism, a major source of income for the Caribbean island.

Sensitive to its economic plight, the government initially kept quiet about the eye epidemic, then suggested the United States might be to blame for a kind of germ warfare. Then, realizing it needed help, officials did an about-face and urged doctors from the United States and elsewhere to come to Cuba.

Castro has kept a close watch on the progress of the disease and research into its cause.

Doctors discovered deficiencies of B vitamins and folic acid but ruled them out as the cause of the epidemic when a control group of people without the disease also was found to be lacking that nourishment.

They knew, however, that nutrition was a factor in allowing the disease to find a victim because pregnant women and children younger than 8--groups that receive extra rations of milk and food--had not fallen ill.

In May, the government began distributing vitamins at a cost of $17 million a year. Antelo estimated the total cost of the epidemic so far at $40 million--a huge bite for the stricken Cuban economy.

Doctors virtually ruled out a virus or bacteria when they realized that children were not affected--most victims are older than 15.

That left a toxic substance. Although large levels of cyanide and methanol have not shown up in the blood of victims, doctors still suspect they may be among the causes of the disease in a population weakened by vitamin and folic acid deficiencies.

Similar nerve epidemics have occasionally appeared in other areas of the world. In Japan, three years ago, about 800 people were stricken by an optic nerve disease from a contaminant. Likewise, in Spain a decade ago, 500 to 600 people suffered a nerve disease that was the result of contaminated olive oil. There were some fatalities in both those cases.