How do you stop the world's worst cholera epidemic?

One way is to send volunteers door-to-door to tell people how they can avoid the disease and what to do if they suspect an infection.

That's what Faytha Ahmed Farj is doing. A 45-year-old mother of 9, Farj has never held a paying job but she's part of a nationwide campaign of volunteers fighting cholera.

Since April, more than 600,000 cases across Yemen have been reported. There was a time when so many sick people were arriving at the cholera center of Alsadaqah Hospital in southern Yemen that patients had to share beds. Health authorities say the numbers are the highest ever seen in one country. The deputy manager and head of the center, Nahla Arishi, was seeing some 300 people a day.

But the rampant spread of cholera has slowed in the poorest country in the Arabian Peninsula. says weekly cases have declined to 35,000 from a high of about 50,000. Nowadays, Arishi sees some 50 patients with signs of cholera in any given day. Humanitarian organizations can take credit for a lot of that success. But so can regular Yemenis like Farj.

She joined the effort after her eldest son caught the illness. She is one of more than 40,000 trained volunteers across the country who have been crisscrossing their cities and villages on foot in the hopes getting out the word on cholera prevention.

Cholera most commonly spreads when a person eats food or drinks water that has been contaminated by feces. It is curable yet can be fatal. And in Yemen, the epidemic stems from the civil war that began in 2014. Years of fighting between the Houthis, an Iranian-backed Shiite group and the Sunni government, along with airstrikes led by Saudi Arabia, have deteriorated the country's infrastructure. Thousands of civil workers stopped receiving salaries. Vital services ceased, like garbage collection and sewage treatment. Millions of Yemenis lack access to clean water, and more than half of their health facilities are shuttered.

By 8 a.m. most mornings, Farj walks down the streets of different neighborhoods in Sanaa, the capital and her home city. Covered in a niqab from head to toe with only her eyes showing, she knocks on doors to houses and teaches the families inside about the simple things they can do to prevent contracting cholera: washing their hands with soap, boiling their water, rinsing off and cooking their vegetables. In one day, she reaches about 25 houses. It's six days a week, at least six hours a day. Not counting weddings and social gatherings where she takes it upon herself to warn people about cholera.

Walking from house to house can be dangerous. Local agreements made between organizations, authorities, tribes and armed groups allow health workers to enter areas with neutrality. But things can still happen. "There was more than one occasion when clashes erupted between civilians and soldiers while we were doing the house-to-house campaign," says Farj, who spoke to NPR through an interpreter via Skype. There are also the airstrikes. "I hide in one of the houses," she says. When the danger passes, she steps outside to go to the next house.

The people on the other side of the door have often seen their loved ones suffer from cholera's telltale symptom — acute, watery diarrhea. One time, Farj walked into a home where three children, a girl and two boys, were showing these signs of cholera. Their mother had thought it was just a common infection. The family also didn't have enough money to buy food, let alone travel to a cholera center to treat their children. Farj notified a charity that transported the children to a health-care center, where all three were treated and cured for cholera.

According to UNICEF, local volunteers in all of Yemen's 22 governorates have reached about 12.5 million people — most of Yemen's households. Some 250,000 children and adults have been treated at the urging of a volunteer and been treated for diarrhea. Farj's son, now 26, also recovered from cholera. "What makes me continue working is that people need help," she says. "No matter how little it is. With my little volunteer work I hope that I can save lives. But more needs to be done."

Other kinds of volunteers are helping to hold their country together. "Health workers, nurses, doctors continue to go on and treat patients without a salary. For me, those are the unsung heroes of this whole crisis," says Meritxell Relaño, the UNICEF representative in Yemen who has been working in the country since October 2015.

Relaño recalls a veiled gynecologist in the port city of Hodeidah. The woman was showing her the maternity ward in a hospital where UNICEF was supplying incubators for newborns. The doctor said nothing about being unpaid until Relaño asked. She told Relaño that she couldn't sit at home when her skills were needed. "She couldn't let those mothers deliver on their own. She couldn't let those children die," says Relaño.

It was the same at schools. Unpaid teachers told Relaño that they keep working because when the war ends, they don't want to have a generation of uneducated children.

Yemen is still facing famine, meningitis and other serious health risks. Out of desperation, poor families are marrying off young daughters for the dowry and to have one less mouth to feed. Boys are joining armed groups because it's their families' only source of income at this time.But many Yemenis go on with pride, says Relaño. "There is always humor, there is always an inshallah, there is always an optimism, there is always the thinking that things will get better."

Translator for Faytha Ahmed Farj: Malak Shaher

Sasha Ingber is a multimedia journalist who has covered science, culture and foreign affairs for such publications asNational Geographic, The Washington Post Magazine andSmithsonian. You can contact her@SashaIngber.

Copyright 2021 NPR. To see more, visit https://www.npr.org.