For more than half a century, those collectors were the zabaleen, a community of Egyptian Christians who live on the cliffs on the eastern edge of the city. They collected the trash, sold the recyclables and fed the organic waste to their pigs — which they then slaughtered and ate.

Killing all the pigs, all at once, “was the stupidest thing they ever did,” Ms. Kamel said, adding, “This is just one more example of poorly informed decision makers.”

When the swine flu fear first emerged, long before even one case was reported in Egypt, President Hosni Mubarak ordered that all the pigs be killed in order to prevent the spread of the disease.