The worst outbreak of the deadly Ebola virus since its discovery nearly four decades ago dominated headlines worldwide in 2014. More than 17,000 cases in eight countries have been reported so far this year, resulting in more than 6,000 deaths, according to the World Health Organization (WHO).
Three countries in West Africa have borne the brunt of the disease -- Guinea, Liberia and Sierra Leone -- accounting for all but 34 cases and 15 deaths through November 30, according to the latest WHO data.
This past year also saw a spike in certain communicable diseases that, unlike Ebola, can be prevented with vaccines.
But 2014 brought some good news on the health front as well, including breakthroughs in treating Hepatitis C and the use of fecal matter as a potential treatment for bacterial infections.
Here’s a look back at some of the key health setbacks and advances in 2014.
Ebola
The Ebola outbreak struck Guinea, Liberia and Sierra Leone particularly hard in part because health services in these countries “are very stretched,” said Nick Beeching, a senior lecturer and consulting physician at the Liverpool School of Tropical Medicine in England.
"And also there is understandably a lot of fear in the local population, who are not always very keen on being quarantined," Beeching told RFE/RL.
Ebola is spread via direct contact with body fluids, whereas viruses like swine flu and SARS, both of which have seen outbreaks in recent years, are spread through the air, Beeching noted.
Transmission of Ebola can also occur by eating a wild animal infected with the virus or direct contact with an infected surface. But religious rites in handling dead bodies also played a role in this year’s outbreak.
Burying the bodies of Ebola victims was linked to 20 percent of the total infections in 2014, according to the WHO. The virus can still live inside a dead body, and burial practices involving touching or washing an infected corpse can facilitate transmission.
WHO officials noted with optimism in early December that more than 70 percent of Ebola victims’ bodies were being buried in a safe manner.
While West Africa suffered in the Ebola outbreak more than any other region, the spread of the virus stoked fear throughout the world as well.
Several U.S. states instituted policies to quarantine health workers who had come into contact with Ebola patients, a move that went beyond federal policy and drew sharp criticism from public health experts.
The global death rate for reported cases of Ebola in 2014 stood at just over 35 percent, according to the latest WHO data.
Those treated for Ebola in the United States fared better statistically, with a death rate of 20 percent. Out of 10 U.S.-based Ebola patients this year -- all but two of whom are believed to have contracted the virus in West Africa -- two have died.
An 'Extraordinary Event'
Other communicable diseases for which vaccines have long existed plagued both the developed and developing worlds in 2014.
U.S. cases of measles reached a 20-year high in 2014, according to the U.S. Centers for Disease Control and Prevention (CDC), which attributes the rise to unvaccinated individuals who brought the virus back to the United States and infected others.
The WHO warned that efforts to eliminate the disease have stalled due to a lack of progress in increasing vaccination coverage. In November, it reported that the number of deaths from measles worldwide rose to an estimated 145,700 in 2013, up from 122,000 the previous year.
The spread of polio in 2014 constituted an "extraordinary event," according to the WHO, which has registered a total of 306 cases so far this year -- 260 in Pakistan alone. The virus, which is preventable through immunization, can cause a lifetime of paralysis.
Pakistani officials have linked the polio surge to the case of a Pakistani doctor accused of using a fake hepatitis B vaccination program to confirm the location of Al-Qaeda leader Osama bin Laden, who was killed in a May 2011 raid by U.S. special forces in the Pakistani garrison town of Abbottabad.
Taliban militants in Pakistan have banned immunizations and attacked polio vaccination teams, accusing them of acting as spies for the United States. The White House said in May that the CIA would not use fake vaccination programs as a cover for spying.
Meanwhile, Middle East Respiratory Syndrome (MERS), a disease with no cure or vaccine that causes pneumonia-like symptoms, saw an uptick centered in Saudi Arabia in 2014. The disease is believed to originate in camels, and contact with the animals is seen as a risk factor. Some MERS victims, however, have reportedly had no contact with camels.
The Western Hemisphere was also hit with an outbreak of Chikungunya Fever in 2014. The WHO has registered more than 776,000 cases of the disease in the Caribbean since an initial outbreak on the French island of St. Martin last December.
Health officials have attributed 152 deaths to the illness, which is caused by a mosquito-borne virus and typically occurs in Africa and Asia. There is no known vaccine or cure.
New Treatments
Two new drugs offered breakthroughs in the treatment of Hepatitis C, but at a significant cost.
Sovaldi, which costs $84,000 for a full-course of treatment, was approved by the FDA in December of last year. A related drug, Harvoni, was approved in October and costs a reported $94,500 in the United States. The prices have caused consternation among both private and public insurers, but the drugs have fewer side effects, greater effectiveness and a shorter treatment cycle than older medications.
Farther down the pipeline, so-called “poop pills” could be used to cure difficult-to-treat bacterial infections by introducing beneficial gut microbes from another person.
In a study conducted at Massachusetts General Hospital, 15 pills of frozen human fecal matter, taken for two days, cured 14 out of 20 patients suffering from Constridium difficile, a bacteria that causes diarrhea and can lead to serious intestinal disorders.
An additional four patients were cured after re-treatment, according to the study, which was published in November.
While likely unappealing to many, the pill form is easier and less invasive than a fecal transplant into the stomach in order to inject the helpful outside bacteria into the patient’s system.
Eat Carbs, Not Fat
Studies in 2014 also revealed new findings about diet and alcohol consumption.
A February study published in the medical journal “JAMA Internal Medicine” found that Americans who consumed more than 25 percent of their calories from sugar were almost three times as likely to die from heart disease than those whose calorie intake consisted of less than 10 percent sugar.
A yearlong study funded by the U.S. National Institute of Health and published in September, meanwhile, found that a low-carbohydrate diet was more effective for weight loss and reducing cardiovascular risk than a low-fat diet.
In alcohol-related developments, a CDC report published in November found that 90 percent of binge drinkers are not alcohol-dependent. The authors note that the study could shift the paradigm for addressing alcohol abuse away from addiction treatment and toward harm reduction.