The death toll in west Africa's three-nation Ebola outbreak has risen to 337, the World Health Organisation said Wednesday, making it the deadliest ever outbreak of the haemorrhagic fever.

Fresh data from the U.N. health agency showed that the number of deaths in Guinea, the hardest-hit country, has reached 264, while 49 had died in Sierra Leone and 24 in Liberia.

U.S. senators ripped at electronic cigarette makers Wednesday for their aggressive marketing campaigns to lure youths that have drawn parallels to those once used by Big Tobacco.

E-cigarettes, a tar-free alternative that release nicotine in a vapor instead of smoke and contain fewer toxins, are booming in the United States, with a market estimated at $1 billion last year.

Morocco's health minister has advised the country's Muslim faithful against making pilgrimages to Saudi Arabia this year, with the deadly MERS virus having killed nearly 300 people there so far.

Last week, the health ministry urged the sick and the frail to postpone any planned pilgrimages until 2015, and circulated among those determined to go information on the health risks from the virus.

The death toll in west Africa's three-nation Ebola outbreak has risen to 337, the World Health Organization said Wednesday, making it the deadliest ever outbreak of the hemorrhagic fever.

Fresh data from the U.N. health agency showed that the number of deaths in Guinea, the hardest-hit country, has reached 264, while 49 had died in Sierra Leone and 24 in Liberia.

Ihor Lakatosh struggles to describe his life before the surgeries, when his severe burns went untreated for years in his native Ukraine, leaving him with one arm fused to his body, unable to walk and abandoned by his mother.

The 11-year-old boy, however, smiles widely and repeatedly makes the sign of the cross when he describes how he feels now, after a series of surgeries and physical therapy at a Boston charity hospital. "Thank you I can walk. Thank you I can walk. Thank you Lord, I can walk," he said recently through an interpreter.

A bill that would have made California the first state in the nation to require warning labels on sodas and other sugary drinks was effectively killed Tuesday.

Sen. Bill Monning's SB1000 failed on a 7-8 vote as his fellow Democratic lawmakers doubted whether a label would change consumer behavior. It needed 10 votes to pass.

Seven people believed to have the Ebola virus have died in recent days in the first deaths reported in the Liberian capital since the outbreak began, a health official said Tuesday.

Deputy Health Minister Tolbert Nyenswah told The Associated Press that brings to 16 the number of people believed to have died from the virus in the West African country. Four of the deaths were confirmed by tests to be Ebola, he said.

Women with a specific gene mutation have a higher risk of dying from a type of breast cancer, said a study Tuesday that raised prospects of targeted drugs.

Previous research had shown that the chances of surviving breast cancer after treatment were partly inherited. It was suspected that genes in the body's immune system were involved, but it was unclear which ones.

The World Health Organization says efforts to prevent the spread of a dangerous virus need to be stepped up ahead of the start of the pilgrimage season to Saudi Arabia.

The vast majority of the 701 confirmed cases and 249 deaths worldwide from Middle East respiratory syndrome have occurred in that country.

Want to make a bet? The answer probably lies in your genes.

Researchers said Monday that a study of more than 200 people has shown that genetics plays a big role in how a person acts when it comes to betting and investing.