美国国家公共电台 NPR--He discovered the origin of the monkeypox outbreak — and tried to warn the world（在线收听）

He discovered the origin of the monkeypox outbreak — and tried to warn the world

Transcript

Five years ago, Dr. Dimie Ogoina saw perhaps the most important patient of his career – a patient whose infection would eventually be linked to the largest monkeypox outbreak in history.

On Sept. 22, 2017, an 11-year-old boy came to Ogoina's clinic with a strange rash on his skin and sores inside his mouth. "He had very large lesions affecting his face and all over his body," says Ogoina, an infectious disease specialist at the Niger Delta University in Nigeria.

The rash looked a bit like chickenpox. "But the boy already had chickenpox," says Ogoina. So he knew that wasn't the problem.

Given the size of the lesions and their location, Ogoina wondered if perhaps the boy had what was then an extremely rare disease: monkeypox. "The suspicion of monkeypox just came up," he says.

At the time, Nigeria didn't have the ability to test for the disease. "So we had to send our samples to Senegal and even to the U.S. to make a diagnosis," he says. "We had to wait."

A few days later, the results came back, and Ogoina was correct: The boy had monkeypox.

"He was the first case of monkeypox in Nigeria in 38 years," Ogoina says. Over the next few months, he and his colleagues detected more than 20 additional cases at their clinic.

Now scientists, including Ogoina, are just starting to realize this little boy was another first, not just for Nigeria, but also for the entire world. He was the first known case of the international monkeypox outbreak, currently spreading in 78 countries.

Since May, the world has detected more than 20,000 monkeypox cases, including more than 4,000 cases in the U.S. Last weekend, the World Health Organization declared this outbreak a public health emergency.

Scientists are beginning to understand where and when this massive outbreak began. And they've traced it back to cases that occurred in Nigeria in 2017 – including the cases that Ogoina detected in his clinic. The data indicate that the virus has been transmitting between people continuously in Nigeria for at least five years, probably longer. Eventually, that outbreak spilled out into the rest of the world.

Somebody told him to be quiet

When Ogoina first diagnosed the young boy with monkeypox in 2017, Ogoina thought the virus would act the way it has for more than 50 years in other parts of Africa, the way that scientists described in textbooks. That is, outbreaks typically begin when a person comes into contact with an infected animal. "There was speculation that this young boy played with monkeys around the community," Ogoina says.

But in such instances, the virus didn't spread very easily between people because it was not very contagious, especially between adults. "[In the past], monkeypox affected mainly children," Ogoina says.

As a result, previous outbreaks of monkeypox have been small. They often involved only a few dozen cases. And they petered out on their own.

Ogoina and other doctors thought the outbreak in 2017 would be the same. "We thought, 'OK, this is the regular monkeypox that we know.' "

But a few weeks after diagnosing the young boy, Ogoina started to become concerned – quite concerned. The outbreak in Nigeria began to grow rapidly. Cases cropped up in counties not just near this one boy but all over. "Suddenly, we were seeing cases appear across the country," Ogoina says.

The virus seemed to be spreading further and faster than expected. And it wasn't infecting kids but rather men in their 20s and 30s. "Young, active men were getting monkeypox," Ogoina says. "It was very unusual at that time."

These men also didn't fit the typical profile for monkeypox patients. They weren't hunting or handling animals but instead were middle-class men, living in busy, modern cities. Ogoina wondered: "Why isn't it affecting children? Or females? Or the elderly? Why are we seeing only young men, ages 20 to 40?" (In fact, Ogoina and his colleague eventually figured out that the young boy didn't even catch the virus from an animal but rather from a male relative in his household.)

And the rashes that affected these patients weren't in the typical places where monkeypox struck. Instead of being on their face and extremities, the blisteres occurred around their genitals. "They had very extensive genital lesions. Very, very extensive," Ogoina says.

Ogoina and his colleagues started to investigate these patients further. "We decided to do a sexual history assessment of some of the cases," he says. That assessment found that many of the patients had high-risk sexual behaviors, including multiple partners and sex with prostitutes.

So there was a huge realization: The virus had changed. For the first time, it was spreading through sexual contact. Ogoina and his colleagues even mentioned the idea in study published in 2019: "Although the role of sexual transmission of human monkeypox is not established, sexual transmission is plausible in some of these patients through close, skin-to-skin contact during sexual intercourse or by transmission via genital secretions," Ogoina and his colleagues wrote in the journal PLOS One.

Ogoina knew this shift in transmission had massive implications. It meant the monkeypox virus could more easily spread from person to person, that it no longer needed to jump from an animal into people. That it could possibly sustain human-to-human transmission in a way that it couldn't before. That meant the outbreak in Nigeria would be much more difficult to stop. It could possibly go on for years and eventually spill over into other countries. In many ways, the findings meant that monkeypox was no longer just a threat to communities in West and Central Africa but also a potential threat to the world.

Over the past few years, Ogoina says he has tried to warn health officials and scientists repeatedly that monkeypox had changed and was possibly spreading through sexual contact. At one international meeting, he tried to bring up the possibility of sexual transmission. Somebody told him to be quiet.

"Yes, someone told me that I should not say it. That I should not say sexual transmission is possible," Ogoina recalls with exasperation in his voice. "He told me, 'We should not worry about sexual transmission.' "

An outbreak that never ended

In 2017, Nigeria reported about 200 cases of monkeypox. And then all of a sudden, by the beginning of 2018, cases declined rapidly. On the surface, it looked as though the country had successfully controlled the virus and the outbreak had ended, just as all previous monkeypox outbreaks had.

But Ogoina says that wasn't the case. Instead, he says, health officials slowed down their search for new cases. "Over time, interest and attention to monkeypox just dropped. Surveillance declined," he says. "The number of cases we've had in Nigeria is not a true representation of actual cases because we are not doing sufficient surveillance." (NPR emailed numerous scientists at the Nigeria Centre for Disease Control for this story but have not heard back.)

New genetic data, collected by researchers around the world, supports Ogoina's hypothesis. Evolutionary biologist Michael Worobey at the University of Arizona has been analyzing this data.

The data indicates that, indeed, the monkeypox outbreak in Nigeria never stopped, Worobey says. Instead, transmission of the virus went underground in Nigeria for years. And eventually the outbreak there spread to other countries and turned into the growing international outbreak the world is fighting now.

Worobey hasn't published his analysis yet, but he says the data are indisputable. "It's clear that there's been continuous cases – or endemic transmission – in Nigeria since 2017, maybe a little bit before 2017. Then something from there got exported out [to the rest of world]," says Worobey.

Altogether, these findings mean the world had nearly five years to snuff out monkeypox – to prevent this virus from possibly becoming entrenched, not just in Nigeria, but in Europe and North America.

But the international effort to stop the outbreak in Nigeria has paled in comparison to the effort to stop monkeypox elsewhere, both Ogoina and Worobey point out.

For example, when doctors diagnosed the first cases in the U.K and Spain in May, immediately health officials pushed to begin to immunize people at risk or who had been exposed to the virus with the monkeypox vaccine. Here in the U.S, health-care workers have vaccinated tens of thousands of people, and the federal government has acquired more than 300,000 doses of vaccine.

How many Nigerians have received the monkeypox vaccine? Zero.