Every Sunday since she can remember, Annette Sanoh has attended church in Susan’s Bay, a slum of crowded tin-roofed homes in Freetown. Now as the Ebola epidemic mushrooms in the capital of Sierra Leone, Sanoh has started going to church services almost every night.

“I believe we are all in God’s hands now. Business is bad because of this Ebola problem, so rather than sit at home, I prefer to go to church and pray because I don’t know what else we can do,” said Sanoh, a market trader. At the church she attends, a small building jammed between a hairdresser’s and two homes, she first washes her hands in a bucket of chlorinated water before joining hands with fellow church members as they pray together.

“We pray Ebola will not be our portion and we pray for hope,” said Sanoh, as the disease this week reached the last remaining district that hadn’t yet recorded a case.

By any measure, West Africa is deeply religious and the region is home to some of the world’s fastest-growing Muslim and Christian populations. Posters and banners strewn across the city are constant reminders of the hope many find in spirituality amid a fearful and increasingly desperate situation. In one supermarket, a notice asking customers to pray for Ebola to end was taped on to a fridge full of butter. It urged Muslims to recite the alfathia; Christians, Our Father; and Hindus Namaste. “For non-believers, please believe in God. Amen, Amina,” it finished.

But officials have fretted about the impact of influential spiritual leaders, worrying that evangelical churches which sometimes hold thousands of faithful and services promising “healing” could ignite new chains of transmission.

As the outbreak races into its eleventh month, leaving behind almost 4,500 dead across Guinea, Liberia and Sierra Leone, experts have warned that an influx of international aid can only contain the epidemic alongside other measures in communities.

“Control of transmission of Ebola in the community, that’s going to be the key for controlling this epidemic,” said Professor Peter Piot, director of the London School of Hygiene and Tropical Medicine, speaking at Oxford University on Thursday.

“Will it be possible without the vaccine? We really don’t know, because it supposes a massive behavioural change in the community; behavioural change about funeral rites, so people don’t touch dead bodies any longer, in carers, as people could be infected while transporting someone to a hospital.”

But there are signs that messages are filtering through. Some churches are playing a critical role in educating their congregations about the disease, which is spread through direct contact with body fluids of those already showing symptoms.

In Liberia, pastor Amos Teah, said once full pews were now largely empty as members feared gathering in crowds, while he has changed the way he conducts his Methodist church services.

“These days we go to church, we sing, but we no longer carry out the tradition of passing the peace. We no longer shake hands. We are even thinking about using spoons to serve communion … to drop the bread into a person’s palm, avoiding all contacts with that person. The church has placed strong emphasis on prevention,” he said.

Among other changes, women no longer wore veils to church, as they were often shared among churchgoers.

In Guinea, an 85% Muslim country, Abou Fofana said he had stopped going to mosque for another reason. “Even though I survived Ebola, nobody wants to come near me. Even my children have faced problems as a result.”

He said he still continued to pray at home. Like many survivors, he credits his faith in helping him pull through.

At the MSF centre in Sierra Leone’s forested interior of Kailahun, Malcolm Hugo, a psychologist, said he hadn’t been able to find an imam willing to visit the centre. So the church services are “mainly filled with Muslims attending,” said Hugo, one particularly bad afternoon in which several children had died.

Health experts and officials warn that the longer the epidemic is left unchecked, the greater the risk of it spreading to other countries in a region where families extend across porous borders.

However, in one piece of rare good news, the UN health agency officially declared an end on Friday to the Ebola outbreak in Senegal. The WHO commended the country on its “diligence to end the transmission of the virus,” citing Senegal’s quick and thorough response.

A case of Ebola in Senegal was confirmed on 29 August in a young man who had travelled by road to Dakar from Guinea, where he had direct contact with an Ebola patient. By 5 September laboratory samples from the patient tested negative, indicating that he had recovered from Ebola. The declaration from WHO came because Senegal made it past the 42-day mark, which is twice the maximum incubation period for Ebola, without detecting more such cases.

“Senegal’s response is a good example of what to do when faced with an imported case of Ebola,” the WHO said in a statement. “The government’s response plan included identifying and monitoring 74 close contacts of the patient, prompt testing of all suspected cases, stepped-up surveillance at the country’s many entry points and nationwide public awareness campaigns.”

“While the outbreak is now officially over, Senegal’s geographical position makes the country vulnerable to additional imported cases of Ebola virus disease,” WHO said.

Additional reporting by Wade Williams in Monrovia

• This article was amended on 18 October 2014. It originally stated that

Malcolm Hugo said he hadn’t been able to find a pastor willing to visit the MSF centre in Kailahun. It should have said he hadn’t been able to find an imam. This has been corrected.

