TANA, Guinea — Sirens blared as the convoy of government vehicles made its way down a narrow dirt road nearly encased by tall weeds. The prime minister had arrived, and he was there to give this rural community a serious scolding.
“I demand the cooperation of the population,” said the prime minister, Mohamed Said Fofana, nearly hollering from his perch on a makeshift bamboo stage.
“Ebola is gone everywhere — except here,” Mr. Fofana told the nearly 300 people gathered around him. “The eyes of the world are on Tana village.”
This is the last known place on Earth with Ebola.
After nearly 22 months and more than 11,300 deaths worldwide, the deadliest Ebola epidemic in history has come down to a handful of cases in a cluster of villages in rural Guinea, the country where the outbreak began.
, where more than 4,800 people died of the virus, has gone about two months since its last Ebola patient was discharged. Sierra Leone, where nearly 4,000 died, is hoping to be declared officially free of Ebola as of Saturday, a milestone defined as going 42 days without a single new infection.
And while the virus once raged in Guinea, now it is merely smoldering, with seven new cases reported in recent weeks. Yet it is proving frustratingly difficult to stamp out altogether.
Getting to zero — as the effort to finally stop the outbreak is known — has bedeviled governments and international health experts for months. Workers from aid groups have descended on the villages where the virus is still spreading, a promising experimental vaccine is being given to adults who have been in contact with a victim, and government officials, once reluctant to acknowledge the dangerous outbreak, are helping to wipe it out.
But even with hundreds of millions of dollars spent to fight this outbreak, the approach to stamping out the disease remains uneven, at best. Workers on the front lines are still making rookie mistakes. Guards at Ebola checkpoints skip over some vehicle passengers for fever checks. Health workers use bare hands to touch people who might harbor the virus. Isolated communities experiencing Ebola for the first time are reluctant to take meticulous precautions and do not trust aid workers.
The risk of a flare-up is still very real. Nearly 150 people were in close contact with the new victims, so they are now at risk of becoming contaminated themselves. Beyond that, more than 200 people who had brief contact with one victim, maybe sharing a taxi, cannot be traced at all.
“We are all holding our breath, frankly,” said Christopher Dye, director of strategy at the World Health Organization who is heading the Ebola epidemiology response.
Officials in Sierra Leone are particularly on edge. Their border is less than 20 miles from the new cases here in Guinea, and the flow of people across porous national boundaries is a chief reason the virus was able to spread throughout the region so easily.
Mr. Fofana came to Tana himself on a search mission.
“A woman is missing and I can’t understand why,” the prime minister shouted, castigating residents to monitor the sick.
The woman, Aminata Camara, had cared for a friend who died of Ebola, making her a likely next victim. Then Ms. Camara vanished. No one offered any clues after she went into hiding, so the authorities jailed her husband, a heavy-handed approach meant to convey the seriousness of the problem. Mr. Fofana announced that if she did not turn up soon, he would fire the village chief.
But while the uncooperative witness here in Forécariah prefecture was jailed, others who have been in close contact with highly contagious patients roam freely.
There are other mysteries to solve. Victims have turned up seemingly out of nowhere, exposing either flaws in the plan to contain the disease or, just as troubling, the possibility that the virus is spreading through survivors, most likely through semen, a transmission path suspected in a case here.
“The aftermath coming out of Ebola disease is something unknown to just about everybody,” said Jean-Vivien Mombouli, a top Ebola adviser to the government of Guinea.
The gravity of the situation is evident in the tiny village of Tana, where more than 100 international health workers, community volunteers and even anthropologists have moved into giant white tents close to the doorsteps of recent victims, with a task that has eluded some of the top medical minds on the planet.
So far, their strategy has not worked.
The fact that Guinea was never hit as hard as Sierra Leone or Liberia may also explain why Ebola has been so difficult to wipe out here.
“In Guinea, we never had this apocalyptic transmission like in Liberia and Sierra Leone; we never had bodies in the streets,” said Ranu Dhillon, a public health expert advising the president’s office in Guinea. “We never had that same kind of critical moment in terms of national response.”
On a recent afternoon, Seydouba Soumah sat dazed on a bench as his young children ran in circles around him. They are motherless, and he is a widower twice over. Both of his wives died recently of Ebola, and he has other children who are hospitalized with the infection, too. He stared ahead in silence as health workers took his temperature. He, too, is at great risk of the disease, and so are the children underfoot.
“The prime minister is right to ask the community to mobilize,” said Makhissa Sako, a mother of five in a village smack in the middle of the current outbreak. “This sickness is hard. Ebola kills.”
The chain of recent infections in this part of Guinea arrived in mid-September, after a girl staying with relatives in the capital, Conakry, returned home to seek care from a traditional healer and died. She passed through one Ebola checkpoint where she registered a fever but was allowed to continue, Doctors Without Borders says, and dodged others by taking back roads.
A team of international health workers soon swooped into the village, fanning out to identify everyone the girl had been in contact with, but encountering resistance from residents who were wary of disclosing personal details to strangers.
Workers trying to ensure that Ebola victims were safely buried in this region were beaten this year. In September 2014, eight people — health workers, local officials and journalists — were killed, a reflection of longstanding political tensions that have made fighting Ebola in Guinea all the more difficult.
Clashes have decreased as the disease has tempered. But the recent presidential election and fears of unrest complicated relief efforts and prompted more conspiracy theories about the disease. The slogan “Ebola is real,” which appears on sun-bleached signs and billboards throughout the country, speaks to the challenge that endures.
“Getting to this stage has taken massive resources, but getting to zero and staying there requires the most meticulous, difficult work of all,” read a recent Doctors Without Borders bulletin. “We cannot lose focus now.”
The government and aid groups have worked to prevent infections with radio broadcasts, bumper stickers and T-shirts about hand-washing and symptoms. For the most part, the dead are now given safe burials — a major break from tradition — as residents have learned that virus-laden corpses are highly contagious.
Yet the degree of threat appears to be open to interpretation here, even among health workers in high-risk zones who manage it inconsistently.
Workers without gloves or other protection touch and play with the children of people who have contracted the virus. On Tuesday, a woman at the tail end of being monitored for signs of Ebola gave birth in her home. Aid workers without gloves emerged after cleaning the floor, leaving behind bloody rags that were still underfoot where the mother cradled her newborn.
While other nations have quarantined victims’ friends and family, Guinea, in an attempt to build trust, is taking a more subtle approach, requiring temperature checks and monitoring twice a day so that people can be isolated if they show symptoms of Ebola. Between checks, they are free to roam. Experts say strict quarantines that isolate families have proved counterproductive, sometimes leading people to lie or flee.
Over the weekend, a 3-year-old boy whose mother had just died of Ebola chased other children in his yard and down the road, giggling and weaving between adults.
“You see how he’s happy and joking,” said Dr. Boubacar Diallo, the W.H.O. physician in charge of tracking down contacts of victims. But the doctor was wary. “The signs and symptoms could start right there.”
On Thursday, Dr. Diallo abruptly changed course and isolated the boy and his siblings. With the government’s blessing, they were taken to a fenced-in Ebola treatment center in the capital for monitoring.
After the first death here in September, aid workers bombarded the victim’s relatives with questions: Who cared for her? With whom did she share a meal, a bed, or a car?
So many questions had been asked that it was almost predictable who would test positive next: first the healer who treated her, then his assistant, then the healer’s wife and later the girl’s sister. The disease was spreading, but in anticipated fashion.
Then, out of nowhere, on Oct. 13, the corpse of a woman in a village down the road, who had not been identified as having been close to any of the new victims, tested positive for Ebola. No one had mentioned her to workers, let alone sought medical help from the troupe of top doctors camped out less than a mile away.
“Something escaped from the team,” said Dr. Diallo, whose tenure in Guinea stretches from the initial case in the outbreak. “We are not quite sure what happened.”
It was also unclear whether the heavy-handed approach wielded by the prime minister would be effective. Some aid workers were appalled at tactics like imprisonment and threats to force a respected village chief to step down.
“What works in the long term is building trust,” said Laurence Sailly, emergency coordinator for Ebola in Guinea for Doctors Without Borders. “If you scare them, it’s going to be difficult next time.”
Ms. Camara has been missing now for just over two weeks. At this point, considering the contact she had with someone with Ebola, health workers said she is most likely very sick, perhaps even dead. Or maybe she never contracted the virus, they said. Maybe she is one of the lucky ones.