Health officials said Monday they expect the first patient in the United States diagnosed with a mysterious virus from the Middle East to be released soon from a hospital, though he could continue to be isolated at home.

The man has been hospitalized at a hospital in Indiana state since April 28. Officials said he fell ill with Middle East Respiratory Syndrome, or MERS, after flying to the U.S. last month from Saudi Arabia, where he is a health care worker.

Somalia is the worst country on Earth to be a mother, according to a report published by Save the Children on Monday which calls for more action to protect mothers and children in crisis-hit areas.

The London-based charity estimates that 800 mothers and 18,000 young children are dying around the world every day from largely preventable causes.

The only known U.S. case of the dangerous Middle East respiratory virus -- a medical worker who became ill after traveling to Saudi Arabia -- is improving, health officials said Monday.

No additional cases had been identified as of Sunday, the Indiana Department of Health said, adding that a press conference would be held at 1530 GMT to give further details.

The World Health Organization warned Monday that polio has reemerged as a public health emergency, after new cases of the crippling disease began surfacing and spreading across borders from countries like Syria and Pakistan.

"The conditions for a public health emergency of international concern have been met," WHO assistant director general Bruce Aylward told reporters in Geneva following crisis talks on the virus long thought to be on the road to extinction.

The countries of west Africa's Mano River Union -- Guinea, Liberia and Sierra Leone -- kicked off a summit meeting on Sunday with the region's Ebola outbreak high on the agenda.

Presidents Ellen Johnson Sirleaf of Liberia and Ernest Bai Koroma of Sierra Leone were in Conakry for the closed-door talks with their Guinean counterpart Alpha Conde, joined by Ivory Coast Foreign Minister Charles Diby Koffi.

A large study in Sweden has shown that genes are just as important as environmental factors in assessing the causes of autism.

Researchers were surprised to discover that the inheritability of the neurodevelopmental disorder was about 50 percent -- much lower than previous studies that put it at 80-90 percent -- and that it was equal to environmental causes, according to the study published in the Journal of the American Medical Association.

Young blood may hold the long-sought cure for the decline of the ageing brain, according to research which showed injections of juvenile mouse blood boosting learning and memory in older rodents, scientists said Sunday.

Multiple blood transfusions from three-month-old mice, the equivalent age of 20 to 30 years old in humans, yielded improvements in the brain structure and function of 18-month-old rodents -- about 56 to 69 in human years, a team wrote in the journal Nature Medicine.

Saudi Arabia's health ministry says one more patient who contracted the potentially fatal Middle East virus related to SARS has died and that 14 new cases have been detected.

The ministry said on its website Sunday that a Saudi man in his 70s died in Riyadh. It says this brings to 112 the number of deaths from the virus in the kingdom since September 2012.

Saudi health authorities announced Saturday two new deaths from the MERS coronavirus, raising to 111 the number of fatalities since the disease appeared in the kingdom in September 2012.

A 25-year-old man has died in the Red Sea port city of Jeddah and a woman of 69, who suffered from tuberculosis and anemia, died in Mecca, also in western Saudi Arabia, the health ministry said.

The first case of MERS, a dangerous respiratory virus that originated in the Middle East and has a high death rate, has been confirmed in the United States, officials said Friday.

The person infected with Middle East Respiratory Syndrome Coronavirus (MERS-CoV) is a health care provider who had traveled to Riyadh for work, the Centers for Disease Control and Prevention said.