WASHINGTON — President Barack Obama calls it a “belt and suspenders” approach — an extra level of screening at five major U.S. airports to try to catch any travelers from Ebola-ravaged countries who may be carrying the disease.

About 150 travelers a day will have their temperatures checked using no-touch thermometers, and health officials expect false alarms from fevers due to malaria.

The extra screening probably wouldn’t have singled out Thomas Eric Duncan when he arrived from hard-hit Liberia last month, because he had no symptoms while traveling. Duncan, the first person to be diagnosed with Ebola in the U.S., died Wednesday in Dallas.

The disease has killed at least 3,800 people in West Africa with no signs of abating. Thursday, the presidents of Liberia, Guinea and Sierra Leone, the countries hardest hit in the outbreak, are appealing to the World Bank for more help for their nations.

“What we’re paying for now is our failure to have invested in those countries before,” said Francisco Ferreira, the World Bank’s chief economist for Africa. They had only minimal health facilities even before Ebola hit.