KISSI TOWN, Sierra Leone — Military choppers thunder over the slums. Nearly a thousand British soldiers are on the scene, ferrying supplies and hammering together new Ebola clinics. Crates of food and medicine are flowing into the port, and planeloads of experts seem to arrive every day — Ugandan doctors, Chinese epidemiologists, Australian logisticians, even an ambulance specialist from London.

But none of it was reaching Isatu Sesay, a sick teenager. She flipped on her left side, then her right, writhing on a foam mattress, moaning, grimacing, mumbling and squinching her eyes in agony as if she were being stabbed. Her family and neighbors called an Ebola hotline more than 35 times, desperate for an ambulance.

For three days straight, Isatu’s mother did not leave her post on the porch, face gaunt, arms slack, eyes fixed up the road toward the capital, Freetown, where the Ebola command center was less than 45 minutes away.

“This is nonsense,” said M.C. Kabia, coordinator of the volunteer Ebola task force in Isatu’s area. Help rarely came, he said, and people were quietly dying all over the place.