St. George has cared for children who were orphaned by war, were abandoned by their parents and, now, lost their parents to Ebola. Amy Maxmen

It’s impossible to know exactly why the 9-year-old’s initial Ebola test was wrong. Robert Garry, a virologist at Tulane University, speculates that tests could erroneously come back negative if they’re conducted at the earliest stage of infection. Initially, the levels of the virus are so low that molecular tests might miss it. To prevent these mistakes, he says, no one should get a certificate, regardless of what tests might say, before 21 days have passed since the individual’s last contact with an Ebola patient.

Yet as Ebola continues to spread in Sierra Leone, with 7,419 cases as of Dec. 30, Conteh does not want to tempt fate. She has decided to quarantine every new child entering the orphanage — regardless of medical histories, assurances or certificates.

But she needed someone to tend to the newly orphaned quarantined kids. She asked Jalloh if she might be interested in the job of collecting and caring for new arrivals. Experience in this and prior outbreaks suggests that Ebola survivors are immune to the disease, at least temporarily. During her weeks of suffering, Jalloh’s body accumulated antibodies to block the virus’ activity. Those antibodies continue to circulate in her blood, where they immediately shut down new Ebola virus infections.

Inspired by the nurses who treated her at Hastings, Jalloh leaped at the opportunity. On one of her first missions, she accompanied St. George staffers to pick up a baby girl found in the bush by the police. The child was too young to speak, so they decided to call her Naomi. Within a few days, however, the baby became feverish. She was taken to the hospital, was declared Ebola-positive and died.

Then it happened again. This time, a baby sent to St. George had lost both parents to Ebola but showed no symptoms. Jalloh cared for the orphan in St. George’s quarantine room, monitoring his temperature daily. In a photograph tacked to the orphanage wall, Jalloh holds the infant on her lap as if it were her own. When a fever struck, the baby was also sent to the hospital, was declared Ebola-positive and died.

“It’s happened three times now,” says Alimamy Turay, a social worker at the orphanage. “Haja has been such a great help because she can handle these cases.”

Although Jalloh and the management at St. George have thus far prevented Ebola from spreading at the facility, the threat remains. According to Else Kirk, the country director at the Irish aid organization GOAL, potentially infected kids present a heightened danger. “Children are at high risk to spread EVD [Ebola virus disease] due to the fact that they do not display symptoms as clearly as adults and can deteriorate rapidly, quickly becoming infectious to others,” she writes in an email.

In response, Sierra Leone’s government, with support from GOAL, UNICEF and others, has begun to construct observation interim care centers (OICCs), where children suspected of Ebola can be quarantined for 21 days before they move on to places like St. George. At least six OICCs have been constructed in the country thus far. But there is more to do: As of Dec. 31, at least 7,938 Sierra Leonean children have lost one or both parents to Ebola, according to UNICEF, and the number grows every day.

According to the plan, children in OICCs will be divided into cohorts by age and tended to by trained nurses wearing personal protective equipment. Although Ebola survivors seem immune, Kirk says they should still don gloves and rubber boots to minimize risk, however unlikely it may seem.

While St. George, a modest compound of six yellow buildings, lacks the around-the-clock specialized care of these planned care centers, it is not short on spirit. The children play happily in the green forest surrounding their quarters. Jalloh and the social workers who run St. George take pride in their service. “We are all one,” she says. “My wish is that every child that comes here remains only a suspected case and not a real case.”

After the Ebola outbreak ends and schools reopen, she intends to become a nurse.

This story was supported by a travel grant from the Pulitzer Center for Crisis Reporting.