Four people who were infected with a virus causing severe respiratory illness across the country have died, but what role the virus played in the deaths is unclear, health officials said Wednesday.

A 10-year-old Rhode Island girl died last week after suffering both a bacterial infection and infection from enterovirus 68, Rhode Island health officials said. The virus is behind a spike in harsh respiratory illnesses in children since early August.

Five people are being infected with Ebola every hour in Sierra Leone and demand for treatment beds is far outstripping supply, the Save the Children charity warned on Thursday.

If the current "terrifying" rate of infection continues, 10 people every hour will be infected with the deadly virus in the West African country by the end of October, the London-based organisation warned.

Health officials in Pakistan on Thursday said the country was set to break its record for the highest number of polio cases in a year, as Islamist militants continue to prevent vaccination efforts.

"The number of polio cases, recorded this year has reached 187 and if it reaches 200, we will cross our own record of 199 in year 2000," Rana Muhammad Safdar, a senior official at the Pakistan National Institute of Health told AFP.

A declining sense of smell in older people is a strong predictor of death within just five years, according to research published Wednesday.

Thirty-nine percent of study subjects who failed a simple smelling test died during that period, compared to 19 percent of those with moderate smell loss and just 10 percent of those with a healthy sense of smell, the journal PLOS ONE reported.

The U.S. military will send more than a thousand troops to Liberia in coming weeks as part of Washington's effort to counter the Ebola outbreak in west Africa, the Pentagon said Tuesday.

About 700 soldiers from the U.S. Army's 101st Airborne Division and another 700 military engineers are due to deploy to Monrovia around late October, spokesman Rear Admiral John Kirby told reporters.

A UN target for slashing infant deaths will be missed, mainly through failures to roll back infectious disease and complications during pregnancy, experts said on Wednesday.

Under the fourth so-called Millennium Development Goal (MDG), all UN members were meant to reduce deaths among children under five by two-thirds by the end of 2015 from 1990 levels.

President Barack Obama's initiative to study the brain and improve treatment of conditions like Alzheimer's and autism was given a boost Tuesday with the announcement of more than $300 million in funds.

When Obama first established the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) program last year, it had $100 million in initial money for research.

If you purchased caffeine-infused underwear because of promises it will make you thinner, federal regulators say you were hoodwinked — but at least you can get your money back.

The Federal Trade Commission announced Monday that two companies — Norm Thompson Outfitters of Oregon and Wacoal America Inc. of New Jersey — have agreed to refund $1.5 million to consumers who purchased "shapewear" that supposedly can reduce cellulite and fat because it is infused with caffeine, vitamin E and other things.

The U.N. mission to combat Ebola opened its headquarters on Monday in Ghana, where it will coordinate international aid to assist West Africa to combat the accelerating crisis.

This outbreak has spiraled into the worst ever for Ebola, and the World Health Organization says it is has linked more than 3,000 deaths to the disease. Even that frightening figure is likely an underestimate of the true toll, said WHO. Liberia, Sierra Leone and Guinea have been hit hardest. Senegal and Nigeria have also been touched, but have not reported a new case in weeks.

Kids who get treated with broad-spectrum antibiotics before age two face a higher risk of childhood obesity, said a US study on Monday.

The research in the Journal of the American Medical Association (JAMA) Pediatrics is the latest to find a link between weight problems and antibiotics, which can eliminate bacterial infections but also the beneficial intestinal microflora that colonizes the gut.