The doctor who managed to solve the enigma of an epidemic that left 50,000 Cubans with vision problems
As Cuba faced a severe economic crisis in the early 1990s, around 50,000 Cubans suffered, in seemingly inexplicable ways, some type of vision loss.
Initially, the island’s health authorities, as well as experts from the World Health Organization (WHO), believed that it was a viral infection that was spreading through the Cuban population.
But they were wrong.
In May 1993, the American ophthalmologist Alfredo Sadun was consulted by a representative of the WHO about the inexplicable epidemic of blindness in Cuba.
“I can’t remember the exact words, but I’ll paraphrase what he said: ‘The WHO has identified that this is a) likely a viral problem and b) likely to affect the optic nerve,'” he told BBC Witness History.
“I was a kind of specialist and world reference in diseases of the optic nerve, so the request was that I go to Cuba as soon as possible“Said Sadun, who is now a member of the Doheny Eye Institute, affiliated with the University of California, Los Angeles (UCLA), United States.
Approximately 50,000 people had lost their sight on the island and the disease seemed to spread at an alarming rate. The WHO representative wanted Sadun to embark for Cuba that same night.
But the doctor, who was in Miami with his family, negotiated a few more days.
“I explained to him that I had to go back to Los Angeles first, I wanted to have the opportunity to make some phone calls to form the right team to accompany me.”
“(Also) I wanted to spend time in the library. This was before Google, and I needed to investigate various possibilities, “he explained.
And although he was interested in the case, it was something he needed to discuss with his wife, given the nature of the proposal. “The fact that I was getting into a (supposed) viral epidemic that was suddenly blinding people was something I needed to explain to him.”
A special period
The early 1990s were a somewhat challenging period for Cubans and their leader, Fidel Castro.
The collapse of the Soviet Union, providing the Caribbean island with millions of dollars in oil, food and other vital supplies, triggered a severe economic crisis on the island, reinforced by the tightening of the embargo imposed by the United States.
The so-called “special period” was marked by the shortage of several basic products and the adoption of rationing policies.
But at that moment, blindness seemed disconnected from the internal crisis of scarcity, and its rapid spread actually suggested the presence of a virus.
Concerned about a possible viral epidemic so close to its shores, US officials quickly agreed to allow Sadun to go to Cuba, despite the ban on US citizens from traveling to the country and open hostility between the two nations.
And so, in mid-May 1993, the doctor and 11 other health experts flew to Havana.
Meeting with Fidel
Their first meeting in the Cuban capital took place the same night they disembarked, with the room full of scientists and the assistance of Fidel Castro.
“Castro regularly interrupted. Some interruptions seemed minor. Someone would say ‘80% ‘and he would interrupt and say,’ Let’s not exaggerate, it was 78%. ‘
“I interpreted this as a demonstration to everyone that he was in control, that he knew what was going on and that it was not just general supervision,” said the doctor.
And did the Cuban leader feel comfortable with the presence of an American on the island?
“When I arrived, and he introduced me to some people, he introduced me as Alfredo Sadun from WHO. The next day, he introduced me as an Italian doctor and scientist ”.
“He did everything possible to avoid calling me AmericanHe recalled.
Another chance
Cuba was already known for its achievements and expertise in health, but most local authorities were still convinced that the epidemic was caused by a virus.
Sadun, however, he was more skeptical.
He and his team began by analyzing cerebrospinal fluid samples taken from patients who had lost their vision, and they found no traces of white blood cells or proteins, indicating a viral infection.
Furthermore, they found that there were no outbreaks in orphanages, nursing homes, or military barracks; according to him, viral infections tend to spread rapidly in these institutions due to the lack of distance between occupants.
To test his theory that vision problems had something other than viral cause, Sadun needed to find common characteristics among affected patients. He then selected a group of about 20 to analyze.
“We needed to find family connections, father and son, mother and daughter, husband and wife, because then you could find out what those affected had in common. For example, they suddenly use the same cooking oil, ”he explained.
And what he found was that all had lost a great deal of weight.
“In our group, the weight loss ranged from 9 kg to 13 kg. So that gave me an idea of the nutritional basis of the problem, ”he said.
The discovery that diet was probably behind the vision problems was a big step. But he didn’t explain everything.
Why, for example, did some members of the same family who did not live or eat together also experience vision loss?
The answer was found almost by accident.
The explanation
One patient, whose brother had also suffered vision loss but did not live or share meals with her, provided the missing piece to put the puzzle together.
When interviewed by Sadun’s assistant, she said the two met for a walk in the woods.
“And on those walks, they met someone who sold them homemade rum“… And that was the key.
Handmade rum contains traces of methanol, a toxin that a healthy body can deal with. But in someone who is deficient in folic acid due to a poor diet, the methanol in the homemade drink is metabolized to formic acid (format), which, in turn, can cause irreparable damage to the optic nerve.
“At that time, we were all sufficiently convinced that not only was it not a virus, but that this double combination nutritional deficiency, particularly folic acid, and formic acid poisoning, a by-product of methanol, which occurs chronically quite slowly, was reason enough (to cause vision loss) ”, explained the expert.
That same week, Sadun announced his findings to Cuban health officials. Remember that, despite the cold reception of some, Fidel Castro listened carefully and asked what could be done.
The American Doctor recommended the immediate and massive distribution of sfolic acid and vitamin B supplements.
Upgrades and Medals
In a scientific paper subsequently published in the American Journal of Ophthalmology, scientists Robert M Feibel and Jennifer Arch described the episode and said that caused “loss of vision, peripheral neuralgia and other neurological symptoms in more than 50,000 people, or 0.5% of the total population ”of the island, noting that between 3,000 and 4,000 cases of optic neuropathy were registered per week in Cuba during the epidemic.
The Reuters agency also reported the case in 1993, stating that “unconfirmed reports circulated on the island about the increase in the number of diseases caused by vitamin deficiencies and malnutrition (…) Foreign diplomats in Havana said that (the episode) was the the first indication that the health of the Cuban population was being affected by the economic crisis, caused by the collapse of the old Cuban trade and ties with Eastern Europe and the former Soviet Union.
At that time, the Ministry of Health responded, according to Reuters, saying that “our country has a strong health system that is prepared to face the situation” and indicated as an emergency measure the distribution of vitamin B supplements to the population.
By September 1993, the so-called Cuban optic neuropathy epidemic had been controlled. Many patients improved after a few weeks of treatment, but some did not recover.
Sadun’s research work earned him in 2002 a Medal of Honor from the National Academy of Sciences of Cuba.
But he stresses that we must give credit to the Cubans, who knew how to identify, above all, that the injured part of the eyeball was the optic nerve.
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