Nurith Aizenman

The work is dirty, dangerous ... and thankless.

Sanitation workers in lower income countries often endure grueling conditions to perform a service that's vital to keeping their communities healthy. Yet their suffering has largely gone ignored — even by advocates for the poor.

Last weekend's massacre in Las Vegas is only the latest reminder of the persistent gun violence in the United States. And a new set of statistics on the rates of gun violence unrelated to conflict underscores just how outsize U.S. rates of gun deaths are compared with those in much of the rest of the world.

Two weeks ago, Jenny Tolosa found out she was pregnant.

The 23-year-old had no idea. "I didn't have any symptoms," she says. "I totally didn't expect this." She giggles, because she was excited by the news.

But she was also worried. She says her first thought was, "I think I had Zika last December!"

That's the mosquito-borne virus that's spreading through Latin America — and has been linked to the birth defect microcephaly, which causes an abnormally small head and possible brain damage.