Deaths from the MERS virus have surged in Saudi Arabia, health ministry figures showed on Friday, after authorities warned of a seasonal increase in Middle East Respiratory Syndrome coronavirus (MERS-CoV).

The ministry recorded five deaths on Thursday alone, bringing to 16 the number since February 11.

A "superbug" outbreak suspected in the deaths of two Los Angeles hospital patients is raising disturbing questions about the design of a hard-to-clean medical instrument used on more than half a million people in the U.S. every year.

At least seven people — two of whom died — have been infected with a potentially lethal, antibiotic-resistant strain of bacteria after undergoing endoscopic procedures at Ronald Reagan UCLA Medical Center between October and January. More than 170 other patients may also have been exposed, hospital officials said.

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.