That $750 pill and more: 2015's top health stories

Infectious disease outbreaks — from MERS to measles and Ebola — dominated health news in 2015.

Ebola

Two years after the beginning of an Ebola outbreak in West Africa, the virus continued to surprise scientists.

The Ebola outbreak — the largest in history — sickened more than 28,630 people and killed at least 11,300, according to the World Health Organization.

While the epidemic subsided in 2015, the virus has never completely gone away. When 2015 began, there were 330 cases of Ebola, mostly in Sierra Leone. By the beginning of December, West Africa document just three Ebola patients. While there are still no licensed treatments for Ebola, doctors learned that aggressive treatment of dehydration and other symptoms help many patients to survive. In another piece of good news, tests showed that an experimental Ebola vaccine protected everyone vaccinated.

The only Ebola cases today are in Liberia, a nation twice declared "Ebola free."

But vanquishing Ebola could be far more difficult than anyone imagined. Scientists this year documented the first known case of sexual transmission of the virus, and studies suggest that male survivors may be able to spread the virus through their semen for nine months or more after recovering from their illness. Scientists learned that Ebola can find "sanctuaries" not just in semen, but in the eye and central nervous system, which includes the brain and spinal cord, said Amesh Adalja, a senior associate at the Center for Health Security at the University of Pittsburgh Medical Center. In another puzzling case, Scottish nurse Pauline Cafferkey survived Ebola, but later developed a life-threatening case of meningitis likely related to her illness. The massive size of the West African Ebola outbreak gave doctors a chance to study such rare occurrences, Adalja said.

Some health experts say the USA hasn't learned key lessons from Ebola experience

Scientists also learned that Ebola can cause devastating long-term side effects, such as eye pain and vision problems, as well as joint pain so severe that it prevents people from working.

Measles

A measles outbreak that started at Disneyland over the Christmas holidays in 2014 spread to 117 people this year and changed the national conversation about vaccinations. The outbreak spurred California and Vermont to strengthen their school vaccine laws. Vermont repealed its "personal belief" exemption, which allowed unvaccinated children to attend school if their parents objected to vaccines for philosophical reasons. California went even further, putting an end to both personal belief and religious exemptions. California now allows unvaccinated children to attend public school only if there is a medical reason why they shouldn't be vaccinated, such as treatment for cancer.

Measles has infected 84 people in 14 states this year

FDA bans trans fats

In a move expected to save thousands of lives a year, the Food and Drug Administration announced in June that it would require manufacturers to phase out partially hydrogenated oils — the primary source of artery-clogging trans fats — from processed foods over the next three years.

FDA to phase out trans fats from food

New mammogram recommendations

The American Cancer Society released guidelines advising women at average risk of breast cancer to begin getting annual mammograms at age 45 – five years later than it had previously recommended. The society said it reached this conclusion after carefully weighing both the benefits and harms of mammograms for younger women, whose risk of breast cancer is much lower than that of older women. The society said that women can switch to being screened every other year after age 55, an age at which breast cancers are often less aggressive. In another major change, the society said doctors no longer need to perform breast exams during women's checkups, since these exams have not been shown to save lives.

Sky-rocketing drug costs

Concern over high drug costs has been building for years as the prices of cancer drugs rose above $100,000 a year and Gilead Sciences Inc. priced its breakthrough hepatitis C drug at $84,000 for a 12-week treatment.

Outrage over drug prices boiled over in 2015 after USA TODAY reported that Turing Pharmaceuticals had purchased the rights to an old but vital generic drug called Daraprim — used to treat a life-threatening complication of AIDS — and immediately hiked the price from $13.50 a pill to $750 a pill.

Turing's CEO, former hedge fund manager Martin Shkreli, fanned the fires of public anger by engaging in public fights on Twitter, even calling a business reporter a "moron." Sen. Bernie Sanders, D-Conn., and Rep. Elijiah Cummings, D-Md., announced an investigation of the price increase, along with increases in the cost of heart drugs made by Valent Pharmaceuticals.

The issue resonated with the public. An October poll from the Kaiser Family Foundation found that 77% of those surveyed said that a top priority for Congress and the White House should be "making sure that high-cost drugs for chronic conditions, such as HIV, hepatitis, mental illness and cancer, are affordable to those who need them." In the same survey, 63% said a top priority should be "government action to lower prescription drug prices."