KENEMA, Sierra Leone—Boarding an ambulance in Freetown last Friday, a pair of Ebola patients began what some in Sierra Leone call the journey of no return.

On a blazing afternoon, an ambulance transporting a brother and sister arrived at the Red Cross Ebola clinic just outside the town of Kenema—a four-hour and 190-mile drive from Sierra Leone’s capital. A child’s wails could be heard while a team of six health workers disinfected the vehicle. A naked 14-year-old boy later stepped out, but not his younger sister.

“She’s dead,” shouted one worker near the vehicle. The ambulance then drove slowly to the back of the clinic, where her corpse was unloaded at the morgue.

Sierra Leone’s ambulances zip down freeways, blow by crowded street markets and bob over rutted jungle roads. Yet all that movement has exposed a dangerously disjointed emergency-response system, one that sends gravely ill patients across the country for hospital beds they sometimes don’t live to see.

That has prompted a rethinking of how the country dispatches its emergency vehicles, in the hope of establishing a template for other countries battling Ebola.