More than a billion people worldwide could starve if India and Pakistan unleash nuclear weapons because even a 'limited' nuclear war would cause major climate disruptions, a study warned.

In addition to clouds of radiation which could contaminate farmland far from the center of the blasts, the study found soot released into the atmosphere would devastate crop yields by cooling global temperatures and reducing rainfall worldwide.

The climate in northwestern Europe and the Balkans is becoming suitable for the Asian tiger mosquito, a disease-spreading invasive species, scientists said on Wednesday.

The warning comes from scientists at the University of Liverpool, northwestern England, who say the two regions have been having progressively milder winters and warmer summers.

Obesity, boozing and other lifestyle risks facing teenagers in the rich world are spreading fast to counterparts in poorer countries, a probe published on Wednesday in The Lancet said.

"The high-income world has been grappling with a rising tide of risks for non-communicable diseases, including the problems of obesity, physical inactivity, alcohol, tobacco and illicit drug use," it said.

Top beef exporter the United States revealed Tuesday it had discovered a case of mad cow disease in California, prompting a scramble to reassure consumers at home and abroad.

The U.S. Department of Agriculture reported the country's fourth-ever case of bovine spongiform encephalopathy (BSE), but stressed the outbreak was contained and no meat has entered the food chain.

The number of measles deaths worldwide has apparently dropped by about three-quarters over a decade, according to a new study by the World Health Organization and others.

Most of the deaths were in India and Africa, where not enough children are being immunized.

Uzbekistan on Monday denied media claims that it was secretly sterilizing women, calling the family program of Central Asia's most populous country a model for other states.

"Distorted information on the use of contraception and particularly surgical sterilization in Uzbekistan that regularly appears in the tabloid press has nothing to do with reality," the Uzbek foreign ministry said.

Hungarian diabetics who fail to stick to their diet will be deprived of more modern treatments from July, under a government decree published Monday aimed at cutting health spending.

Diabetics undergo a blood test on average every three months and those who score high levels of glycaemia more than twice a year could be turned away from treatments with analog insulin -- more efficient but also more expensive -- and left with the less efficient human insulin, under the new rules.

It's Sunday lunchtime in Las Vegas and Justin looks like he wants to curl up and die. He has a monster hangover after drinking for two days solid. But help, he hopes, is at hand.

The 38-year-old from Seattle is among the first customers trying out a new service, "Hangover Heaven", which promises to "cure" his throbbing head, sweaty pallor and general feeling of death, all within 45 minutes.

The World Health Organization said Monday it was "concerned" about an outbreak of a mysterious skin disease in central Vietnam which has killed 19 people, mostly children.

More than 170 people have fallen ill with the unidentified illness, which causes stiffness in the limbs and ulcers on victims' hands and feet that look like severe burns.

Chinese researchers said Monday they have discovered an HIV-blocking agent that could be developed into a gel to limit the sexual transmission of AIDS.

Scientists from Hong Kong University said joint research with Shanghai Targetdrug Co., Nanjing University and City University of Hong Kong had discovered a molecule that blocks HIV from entering human cells.