Gree Say recognised the grayish patches down the toddler’s throat only from her textbooks. In more than a decade as a nurse, she had never seen diphtheria, a potentially fatal disease that is preventable through vaccination.

“This isn’t something we have seen here before,” she said.

Gree Say works at the Mae Tao Clinic, a hospital in the Thai border town of Mae Sot that was founded in 1989, after a military crackdown in Myanmar drove waves of refugees toward Thailand. For decades, the clinic has treated migrants and displaced people from across the border. But since Myanmar’s military seized power again in 2021, igniting a nationwide civil war, the demand for care has surged to unprecedented levels.

On a recent weekday, Burmese women cradled restless babies, clutched plastic bags filled with medical records and waited patiently for treatment. Doctors say the number of patients has soared as Myanmar’s health system has collapsed under the strain of war.

Hospitals have been bombed, medical workers arrested or forced to flee, budgets slashed and civilians uprooted by fighting.

The border is so close that staff at Mae Tao can sometimes hear artillery fire and see smoke rising from Myanmar. On the worst days, doctors treat twice as many patients as before the conflict, trying to ease pressure on Thailand’s own health system.

Myanmar’s public health infrastructure had already been weakened by decades of military rule that prioritized weapons over welfare. Some gains were made under a brief period of civilian government, including expanded vaccination and disease-control programs. Those advances were reversed after the coup.

Myanmar now has one of the world’s largest populations of unvaccinated children, according to UNICEF. Doctors working along the border say preventable diseases such as whooping cough and diphtheria are reemerging. Malaria, tuberculosis and HIV are also spreading as routine care and prevention programs break down.

The military has increasingly targeted health care itself. The World Health Organization has documented dozens of attacks on medical facilities this year alone. Earlier this month, an airstrike on a 300-bed hospital near the border with Bangladesh killed at least 34 people.

As airstrikes intensify, villagers and resistance fighters have fled into jungles, where mosquitoes carrying malaria thrive. Some doctors report treating patients who have suffered repeated bouts of the disease over many years.

Thailand had been on track to eliminate malaria by 2024, according to a 2021 WHO report. But the coup in Myanmar derailed that progress. As fighting escalated and population movements increased, malaria cases surged again along the border.

More than three million people have been displaced inside Myanmar. Many now live in remote, rebel-controlled areas where access to treatment is erratic and supplies like mosquito nets, condoms and masks are scarce.

“Many people die not because of the fighting, but because of illness,” said Aye Thida, who helps care for HIV patients at Mae Tao.

Just a few miles away is Maesot General Hospital, a large Thai government facility that has treated Myanmar citizens for decades.

Since the war began, its caseload has increased by about 50 percent. Exhausted doctors have resigned, but the hospital continues to take in Burmese patients.

“If we don’t care about Myanmar’s health situation, we might face reemerging diseases such as polio,” said Dr. Rojanasak Thongkhamcharoen, the hospital’s deputy director. A case of the paralyzing disease was confirmed this summer in northeastern Myanmar.

“Communicable diseases know no borders,” he said.

The risks are not theoretical. Last year, cholera broke out in a scam compound in Myanmar’s lawless borderlands. Thailand rushed medicines to prevent the disease from spreading, yet at least four cases were recorded, including two Thai citizens.

“This crisis should keep people awake at night,” said Dr. Voravit Suwanvanichkij, an epidemiologist who has worked along the Thai-Myanmar border. With much of Myanmar now inaccessible to international aid groups, he warned, the country has become an “epidemiologic blind spot.”

Without functioning disease surveillance, threats such as dangerous virus mutations could be detected too late. Cuts to US foreign aid earlier this year, he added, have further weakened already fragile health programs.

In a worst-case scenario, experts say, Myanmar’s collapse could threaten global health security. Improperly treated malaria can lead to drug-resistant strains, which researchers have previously tracked spreading from Southeast Asia to Africa.

For now, border clinics like Mae Tao remain a critical line of defense — not just for displaced families fleeing war, but for the region beyond Myanmar’s borders.

The New York Times