Closing live poultry markets, though a huge economic setback, is a sure-fire way of curbing the deadly H7N9 bird flu in case of an outbreak, disease control researchers said Thursday.

The closure of 780 live poultry markets (LPMs) in the Chinese cities of Shanghai, Hangzhou, Huzhou and Nanjing in April reduced the daily number of H7N9 infections by more than 97 percent, said a study in The Lancet medical journal.

President Barack Obama's health secretary publicly apologized Wednesday for the rocky rollout of the U.S. health care law's new website, stressing that citizens "deserve better" from the system.

But while Secretary of Health and Human Services Kathleen Sebelius regretted that navigating HealthCare.gov has been a "miserably frustrating experience" for many, she insisted that so-called "Obamacare" has been working well for millions of Americans.

A patient suspected of having contracted the MERS coronavirus has tested negative for the lethal respiratory disease, France's health ministry has announced.

The ministry had initially said Tuesday that a person who had just returned from Saudi Arabia, where the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) first appeared in September 2012, was likely infected by the virus.

Around 7.3 million girls under the age of 18 give birth each year in developing countries, risking death and suffering that can only be addressed by changing social attitudes, a U.N. report said Wednesday.

Most are in sub-Saharan Africa and South Asia, with one in 10 girls in Bangladesh, Chad, Guinea, Mali, Mozambique and Niger reporting having a child before the age of 15, the U.N. Population Fund (UNFPA) said.

Health authorities in Oman announced the first case of MERS coronavirus in the Gulf sultanate, state news agency ONA reported.

The patient, an Omani man, is receiving treatment at a hospital and he is "stable", it said in a statement late Tuesday. "He is suffering from a chest infection."

The U.N. health agency on Tuesday confirmed an outbreak of polio in war-torn Syria, which had been free of the crippling disease since 1999, and said it feared it would spread.

Oliver Rosenbauer, spokesman for the World Health Organization's anti-polio division, told reporters that laboratory tests had confirmed the presence of the disease in 10 out of 22 suspected cases reported in children almost two weeks ago.

Mowing the lawn or washing the car are among simple activities that can reduce the risk of heart attack or stroke by almost 30 percent in people over 60, researchers said Tuesday.

A study in Sweden found that older people who were physically active around the house stayed healthier longer than couch potatoes -- regardless of whether they also did any kind of "formal" exercise like jogging or going to the gym.

The ancient practice of "swaddling" a baby in a blanket, arms restrained and legs stretched out, is making a comeback, but experts warned Tuesday it was bad for infant hips.

While many parents say the technique is soothing and aids their child's sleep, researchers underlined that links have been observed to osteoarthritis and hip replacement in middle age.

In Morocco's drug capital Tangiers, a pioneering clinic is trying to help addicts fight a rising habit in a conservative Muslim state where many would prefer the problem stay underground.

"I don't want to steal from people to get my fix," Mohammed tells a group of around 30 hard drug users who have come to the Hasnouna clinic seeking support.

Parents should limit kids' tweeting and texting and keep smartphones and laptops out of bedrooms, a pediatricans group says.

The recommendations are bound to prompt eye-rolling and laughs from many teens but the influential pediatricians group American Academy of Pediatrics says parents need to know that unrestricted media use can have serious consequences.