Parasites resistant to the frontline malaria drug have spread westward from southeast Asia to just short of the Indian border -- a gateway to Africa, researchers warned Friday.

A spread into India "would pose a serious threat to the global control and eradication of malaria," said a statement that accompanied the study published in The Lancet Infectious Diseases.

Thailand has passed a law banning foreign couples from using Thai women as surrogates after a series of high-profile scandals tainting the image of the hitherto unregulated industry.

The legislation was unanimously approved by Thailand's junta-picked parliament on Thursday in a bill spurred by the case of an Australian couple accused of abandoning a baby with Down's syndrome while taking his healthy twin sister carried by a Thai surrogate.

Tiny nano-particles that act like miniature drones could deliver a knock-out punch to plaque buildup in the arteries, according to an experimental approach described by US scientists on Wednesday.

So far the anti-cholesterol treatment has been tried only in lab mice, while the nanoparticles themselves are in clinical trials for people with cancer.

A consortium of scientists on Wednesday unveiled the largest-ever map of molecular switches that affect genes, a tool that should boost understanding into how diseases are caused.

The work, assembled by scientific publishing house Nature, is the most ambitious look yet at epigenetics, considered one of medicine's most promising frontiers.

A new vaccine against sexually transmitted human papillomavirus is more effective than the previous version and may protect against 90 percent of all cervical cancers worldwide, researchers said Wednesday.

The vaccine, Gardasil 9, is made by Merck, which also funded the study of 14,200 women aged 16-26, published in the New England Journal of Medicine.

The World Health Organization on Thursday urged countries to invest billions of dollars to tackle 17 neglected tropical diseases -- including dengue fever, leprosy and sleeping sickness -- which kill 500,000 people globally each year.

WHO said some 1.5 billion people across 149 countries are affected by the diseases, insisting additional investments would save lives, prevent disability, end suffering and improve productivity.

The flu vaccine may not have protected most people against influenza circulating widely this season, but a study Tuesday showed it was effective against the new H7N9 strain that emerged in China in 2013.

Antibodies that protect against H7N9 avian flu make up a small portion of people's immune response to the annual flu shot, "but appear to broadly neutralize H7 viruses and represent promising new targets for therapeutic development against a wide range of influenza strains," according to the research by the University of Chicago and Icahn School of Medicine at Mount Sinai.

Teenage fathers are likelier to have children with health problems because of mutations in their sperm, a study said Wednesday.

Previous research had found that teens are likelier than 20- to 35-year-olds to father a child with autism, low IQ, schizophrenia or spina bifida, although the risk is low in absolute terms.

Tougher food screening measures could be introduced in Australia with frozen berries from China linked to a growing number of hepatitis A infections, Agriculture Minister Barnaby Joyce said Wednesday.

Nanna's and Creative Gourmet brand raspberries and mixed berries were recalled after they were linked to four infections in New South Wales and Victoria states, with poor hygiene or contaminated water at their packing factory thought to be responsible.

Chinese businesswoman Chen Yili paid a South Korean hospital thousands of dollars to reshape her face in the hope she would look more like the glamorous stars she saw on television.

Instead she says she was disfigured by the operation - one of a growing number of Chinese women who claim shoddy procedures and a lack of regulation in South Korea's booming "medical tourism" industry, have left them physically scarred.