Jason Beaubien

Haitian officials say Hurricane Matthew has left hundreds of thousands of people vulnerable in the country's southern peninsula. As aid workers make their way to towns that have been isolated, the death toll is expected to rise.

Many of them can't go home — hundreds of thousands of houses have been damaged or destroyed. They're stuck in shelters. And they don't know when aid will come.

Officials and aid workers are now able to make their way into parts of the country that were slammed by the storm. They're finding buildings smashed and mud lining the streets.

Reports are beginning to surface from Haiti's southwest coast, which received a direct hit from Hurricane Matthew earlier this week. The storm left the region cut off for days. Thousands of homes have been destroyed, and at least 100 people are reported dead.

And there's another mystery. Why was the father suffering from such a severe case that he eventually died?

Engineering professor Rebecca Richards-Kortum wins a MacArthur Fellowship for inspiring her students to invent medical devices for the developing world.

I couldn't care less about most of the hotels I've stayed in as a foreign correspondent. But the Villa Creole was different.

Last year the country was declared polio-free. Now there are three new cases. And Boko Haram militants are the biggest obstacle to getting rid of the virus.

There are signs that the virus is spreading. And the health system is ill-equipped to detect or care for babies born with microcephaly.

Health care workers are anxious that Zika is spreading across the country undetected — and worry that the system is ill-equipped to deal with severe birth defects.

The country faces one of the worst humanitarian crises in the world. But the brutal rape has left aid agencies wondering whether to pull out their foreign staff.

The U.N. appears to be on the verge of admitting it played a role in introducing cholera to Haiti in 2010. But critics are still waiting for the agency to take full responsibility.

The two new polio cases in Nigeria are the first detected on the African continent in more than two years.

Puerto Rico has more reported cases of Zika than many other places in the region, and the number of cases continues to rise. Unfortunately, Zika is just one of the island's many problems.

Tapeworms, hookworms, leeches. Millions of specimens. This collection has it all — except legs.

With the Zika epidemic raging around them, OB-GYNs in Puerto Rico have launched a plan to offer free contraception across the island. Doctors say the island has a high unplanned pregnancy rate.

The warm, wet summer months in Puerto Rico are the perfect breeding time for the mosquitoes that carry Zika virus. As the mosquitoes multiply there, so do the human cases of infection.

Dr. Marlen Baroso works at the health center in Beira, a port city in Mozambique. She treats patients with ailments, accident victims, women in labor — and thousands of people with HIV.

In a pilot program in South Africa, teens who are not infected with HIV are going on a preventive regimen of anti-AIDS drugs.

It's part of a pilot program from Doctors Without Borders in a part of Mozambique where roughly 1 in 10 adults is infected with the virus.