Climate change, cholera and the return of thousands of emigrants from the neighboring Dominican Republican are fueling a humanitarian crisis in Haiti, the U.N. warned Tuesday.

The impoverished Caribbean nation is facing a deluge of problems, pushing an already vulnerable population closer to the edge, said Enzo di Taranto, who heads Haiti's U.N. Office for the Coordination of Humanitarian Affairs (OCHA).

Typhoid has broken out among Palestinian refugees from the besieged Yarmuk camp in the Syrian capital Damascus, a UN agency said Wednesday.

The UN agency for Palestinian refugees UNRWA said it had been able to confirm the outbreak after gaining access to residents of the camp sheltering in the nearby Yalda neighborhood.

U.S. scientists might have found a new way to tell who's at risk of having a premature baby, by checking the bacterial community that lives in the mother's reproductive tract.

Trillions of microbes share our bodies, living on the skin or in the gut, mouth or vagina, what scientists call our microbiome. Many of these germs play critical roles in health, from good digestion to robust immunity, but they can contribute to health problems if they get out of whack.

Drinking four or more cups of caffeinated coffee daily may significantly reduce the chance that colon cancer will return in patients who were diagnosed with stage III of the disease, a study said Monday.

The study involved about 1,000 patients, all of whom had undergone surgery and chemotherapy for stage III colon cancer.

More money is being spent on medical research but fewer new drugs are being approved and people are not living much longer than they did in the 1960s, said a U.S. study on Monday.

Among the multiple reasons suspected for the stall in medical progress: too much focus on getting published in prestigious journals and excessive red tape and regulation, said the findings in the Proceedings of the National Academy of Sciences.

Being overweight more than doubles the risk of bowel cancer in people with a certain gene disorder, but a regular dose of aspirin can reverse the trend, a study found Monday.

The international study, published in the US-based Journal of Clinical Oncology, followed 937 people with an inherited genetic disorder known as Lynch Syndrome in 16 countries, in some cases over a decade.

A psychological wound known as moral injury is gaining attention in the aftermath of the wars in Iraq and Afghanistan, with U.S. veterans now being treated for these injuries to the soul — even as medical experts debate whether moral injury is a condition unto itself or a subset of post-traumatic stress disorder.

Some questions and answers about moral injury, and how it compares with and differs from PTSD:

A chemical leak sent at least 15 people to a hospital for treatment before it was stopped at a plant on Terre Haute's south side in the U.S. state of Indiana, authorities said.

Firefighters say sulfur dioxide leaked at Hydrite Chemical Co. on Saturday night and winds carried fumes to nearby Hulman-Mini Speedway, where a crowd was watching auto races.

Sierra Leone has ended an Ebola lockdown in the northern village of Massessbe that had kept more than 500 residents in quarantine, as President Ernest Bai Koroma said only two people were still being treated for the virus nationwide.

Koroma himself on Friday cut the yellow ribbon that had ringed the village in the northern district of Tonkolili to mark the completion of the standard 21-day quarantine period, a State House release said.

Niger has stepped up the fight against breast and cervical cancer, using screening and public awareness campaigns to reverse a scourge affecting more and more women in the prime of life.

"The situation in Niger is very alarming," said oncologist Issimouha Dille. "Breast and cervical cancer are serious public health problems."