THE ALBINO MINE, Venezuela -- The 12th time Reinaldo Balocha got malaria, he hardly rested at all. With the fever still rattling his body, he threw a pickax over his shoulder and got back to work -- smashing stones in an illegal gold mine.

As a computer technician from a big city, Balocha was ill-suited for the mines; his soft hands were used to working keyboards, not the earth. But Venezuela's economy collapsed on so many levels that inflation had obliterated his salary, along with his hopes of preserving a middle-class life.

So, like tens of thousands of other people from across the country, Balocha went to the open, swampy mines scattered across the jungle, looking for a future. Here, waiters, office workers, taxi drivers, college graduates and even civil servants on vacation from their government jobs are out panning for black-market gold, all under the watchful eyes of an armed group that taxes them and threatens to tie them to posts if they disobey.

It is a society turned upside down, a place where educated people abandon once-comfortable jobs in the city for dangerous, backbreaking work in muddy pits, desperate to make ends meet. And it comes with a price: Malaria, driven long ago to the fringes of the country, is festering in the mines and back with a vengeance.

Venezuela was the first nation in the world to be certified by the World Health Organization for eradicating malaria in its most populated areas, beating the United States and other developed countries to that milestone in 1961.

Since then, the world has dedicated enormous amounts of time and money to beating back the disease, with deaths plummeting by 60 percent in places with malaria in recent years, according to the WHO.

But in Venezuela, the clock is running backward.

The country's economic turmoil has caused a resurgence in malaria, bringing the disease out of the remote jungle areas where it persisted and spreading it around the nation at levels not seen in Venezuela for 75 years, medical experts say.

Officially, the spread of malaria in Venezuela has become a state secret. The government has not published epidemiological reports on the disease in the past year, and it says there is no crisis.

But the most recent internal figures, obtained by The New York Times from Venezuelan doctors involved in compiling it, confirms a surge is underway.

In the first six months of the year, malaria cases rose 72 percent, to a total of 125,000, according to the figures. The disease cut a wide path through the country, with cases present in more than half of its 23 states. Among the malaria strains present in Venezuela is Plasmodium falciparum, the parasite that causes the most fatal form of the disease.

"It is a situation of national shame," said Dr. Jose Oletta, a former Venezuelan health minister who lives in the capital, Caracas, where malaria cases are now appearing. "I was seeing this kind of thing when I was a medical student a half-century ago. It hurts me. The disease had disappeared."

It all starts with the mines. With the economy in tatters, at least 70,000 people from all walks of life have been streaming into the mines over the past year, said Jorge Moreno, a leading mosquito expert in Venezuela. As they hunt for gold in watery pits, the perfect breeding ground for the mosquitoes that spread the disease, they are catching malaria by the tens of thousands.

Then, with the disease in their blood, they return home to Venezuela's cities. But because of the economic collapse, there is often no medicine and little fumigation to prevent mosquitoes there from biting them and passing malaria to others, sickening tens of thousands more people and leaving entire towns desperate for help.

The economic breakdown has "triggered a great migration in Venezuela, and right behind it is the spread of malaria," said Moreno, a researcher at a state-run laboratory in the mining region. "With this breakdown comes a disease that is cooked in the same pot."

Five hours away in Ciudad Guayana, a rusting former industrial boom town where many are now jobless and have taken to wildcatting in the mines, a crowd of 300 people packed the waiting room of a clinic in May. All had symptoms of the disease: fevers, icy chills and uncontrollable tremors.

There were no lights because the government had cut power to save electricity. There were no medicines because the Health Ministry had not delivered any. Health workers administered blood tests with their bare hands because they were out of gloves.

Maribel Supero clutched her 23-year-old son as he trembled, unable to speak. Jose Castro held his 18-month-old daughter as she screamed. Griselda Bello, who works at the clinic, waved her hands helplessly and told yet another patient to hold on a bit longer.

The pills had run out. There was nothing she could do.

"Come back tomorrow at 10 a.m.," she said.

"My God," the patient said. "Someone might die by then."

"Indeed, they might," she said.

Information for this article was contributed by Patricia Torres and Clavel Rangel of The New York Times.

A Section on 08/15/2016