Saudi Arabia has reported five new deaths from the MERS respiratory virus, bringing the death toll in the world's worst-hit country to 168.

In its latest tally, issued on Saturday, the health ministry said the total number of infections in the kingdom from the coronavirus since it first appeared in 2012 now stood at 529 people.

An Illinois man has contracted the MERS respiratory virus after coming into contact with the first case of the mysterious Middle East pathogen in the United States, become the third infected person.

It was during an ongoing investigation on the first case of Middle East Respiratory Syndrome Coronavirus in the United States that officials identified the new case, the Centers for Disease Control and Prevention said Saturday.

Health authorities in Saudi Arabia have reported three more fatalities from the MERS respiratory virus, taking the death toll in the world's worst-hit country to 163.

The health ministry website also revealed on Saturday that 520 cases have been recorded in the country since Middle East Respiratory Syndrome first appeared in Saudi Arabia in 2012.

A single daily pill may help prevent HIV. And in America, gay men who have lost countless loved ones to AIDS can't stop fighting about it.

Much of the debate has played out on the Internet and social media as tempers flare over promiscuity, erratic condom use and the potential to either eliminate or worsen the stubborn HIV/AIDS epidemic, which has killed 36 million people worldwide in the past three decades.

The vending machines at a Vancouver storefront look ordinary -- but instead of spitting out gum or snacks, for a few coins they deliver medical marijuana.

For Can$4 (U.S.$3.70), the brightly lit "gumball" machine drops a plastic ball filled with the so-called "Cotton Candy" variety of the drug. The "Purple Kush" option costs Can$6.

Pakistan on Thursday announced that residents of its restive tribal belt would not be able to travel to other parts of the country without getting vaccinating against polio.

The move came days after Pakistan said it would set up mandatory immunisation points at airports to help stop its polio outbreak spreading abroad, in response to new guidelines by the World Health Organization (WHO).

A potent dose of engineered measles virus has been shown for the first time to have completely wiped out a woman's cancer, U.S. scientists reported this week.

"Here we have got a therapy that you give once, and the outcome can be long-term remission of cancer," said lead author Stephen Russell, a hematologist who co-developed the therapy described Wednesday in the Mayo Clinic Proceedings journal. 

Life expectancy in the globe's poorest countries has risen by an average of nine years over the past two decades, thanks to major improvements in infant health, the United Nations said Thursday.

In its annual statistics, the UN's World Health Organization (WHO) said that six of the countries had even managed to raise life expectancy to over 10 years between 1990 and 2012.

U.S. health authorities are recommending the daily use of anti-retroviral medication to prevent HIV infection for high-risk groups.

The new guidelines by the U.S. Centers for Disease Control and Prevention unveiled this week recommends taking Truvada, a pill containing tenofovir and emtricitabine, based on studies that showed the drug can help reduce infection rates by more than 90 percent when taken every day.

Health authorities in Saudi Arabia on Thursday announced the deaths of another three people from the MERS respiratory virus, taking the country's toll to 160.

The health ministry's daily bulletin on the Middle East Respiratory Syndrome outbreak in the Gulf nation said the latest people to die were two women aged 72 and 54 and a 63-year-old man.