For eight weeks, Dr. Komba Songu-M'briwa worked at the understaffed Hastings Ebola Treatment Center outside Sierra Leone's capital. When he began feeling sick, he thought it might be exhaustion but on Nov. 26 he got dreadful news: He had tested positive for Ebola.

Songu-M'briwa and just two other doctors, along with 77 nurses, work at the 120-bed treatment centre. It was the "most difficult, most pitiful" work of his life, the 32-year-old said in a telephone interview with The Associated Press from his isolation room. Even so, he vowed to return to that crucial work if he recovered.

"I do enjoy the work here and I hope and pray once I'm out of here, I'll take a bit of rest, and I'll come back and fight," Songu-M'briwa said on Sunday.

On Monday, Chief Medical Officer Dr. Brima Kargbo announced that Songu-M'briwa had tested "completely negative" for Ebola. An earlier test result had also come back negative.

Songu-M'briwa — Ksong to his friends — doesn't know when or how he became infected. Sierra Leone has lost seven doctors to the disease. The country had only about 135 doctors to begin with, serving 6 million people. Denmark, with roughly as many citizens, has nearly 19,000 doctors, according to the Africa Health, Human & Social Development Information Service.

Health care workers treating Ebola are supposed to spend only about an hour inside a treatment unit because of the dehydration and exhaustion that comes from wearing a sealed protective suit and the focus required to take care of the patients. But there are too many patients to take one-hour shifts at Hastings, Songu-M'briwa said, so he and his colleagues laboured for three or four hours at a time.

When Ebola broke out, I felt it was a fight for all of us to try to contain. - Dr. Komba Songu-M'briwa

"We're stretched out, three of us cannot do all the work here," he said.

He and his colleagues have enough supplies, enough protective suits, enough chlorine, enough food and enough gloves. What they need are more colleagues. Foreign doctors had come to Sierra Leone — their precise number is unclear — but many more are needed.

On Tuesday, Doctors Without Borders said the international response to Ebola is still too slow and piecemeal, given that it says it takes weeks to train people to safely operate case management centres.

The staff relies on patients to help keep an eye on one another and call for help as needed, Songu-M'briwa said. Ebola is spread through contact with bodily fluids, and often whole families are brought in at the same time. When one's condition worsens, a relative is often the one who sounds the alarm, calling doctors back to the ward to attend to the patient.

Most nights, Songu-M'briwa slept at the facility but he tried to go home to see his wife and two children a couple times a week. When he initially started feeling under the weather, he thought the pace had just gotten to him and went home to rest. But his symptoms worsened and when he got a fever he was pretty sure it was Ebola. He called his treatment centre to come get him.

Songu-M'briwa was given his own room at Hastings, but he received treatment similar to that of other patients: general antibiotics to keep other diseases at bay, intravenous fluids to replace fluids lost through diarrhea and vomiting and good nutrition to keep strength up.

Sierra Leone's lack of doctors

He noted that Hastings doesn't have access to experimental drugs or techniques, but that these basic interventions help a lot of people, especially when the infection is caught early, as his was.

"I don't have regrets because I'm enjoying my job, and I think it's been a blessing to other people," he said with an easy laugh.

Sierra Leone's acute lack of doctors and the crumbling health system are partially a legacy of a decade of civil war. Growing up, Songu-M'briwa was good at math and physics and he thought he would be an engineer. But his mother wanted him to be a doctor.

As many former classmates went into private practice in Sierra Leone or left the country, Songu-M'briwa joined the military where he is a captain. He was working at the 34 Military Hospital in Freetown until he volunteered for duty at Hastings.

"When Ebola broke out, I felt it was a fight for all of us to try to contain," he said.

Before contracting Ebola, he had tried rallying his colleagues at 34 Military Hospital to volunteer for Ebola duty and thought he was succeeding. Now his illness "has sent shockwaves," making that effort harder, Songu-M'briwa said.

"But I still tell them, 'don't worry,"' he said. "If I have become infected, I'm going through it … we can all go through it.

"It's not going to stop me. I am not going to relent."