Cuba said it will send nearly 300 more doctors and nurses to west Africa to help fight the Ebola epidemic.

This will raise to 461 the number of Cuban medical personnel that the country will send to battle the disease.

Sierra Leone has ordered the quarantine "with immediate effect" of three districts and 12 tribal chiefdoms -- affecting more than one million people -- in the largest lockdown in west Africa's deadly Ebola outbreak.

President Ernest Bai Koroma, in a national televised address late Wednesday, announced that the northern districts of Port Loko and Bombali were to be closed off along with the southern district of Moyamba -- effectively sealing off around 1.2 million people.

President Goodluck Jonathan appeared to jump the gun on medical advice at home on Wednesday to tell an applauding UN General Assembly that Nigeria was free of the deadly Ebola virus.

"We can confidently say that today Nigeria is Ebola free," Jonathan told the largest diplomatic gathering in the world to a ripple of applause at UN headquarters in New York.

A new government study suggests the number of U.S. adults who have tried electronic cigarettes may be leveling off.

The proportion of adults who have ever used e-cigarettes rose from about 3 percent to 8 percent from 2010 to 2012. But there was no significant change last year, according to the U.S. Centers for Disease Control and Prevention study.

The patient, a slight woman in her 30s, lay motionless on the stretcher as a half-dozen men in biohazard suits transferred her from a C-27J cargo plane into an ambulance and then into a mobile hospital isolation ward, never once breaking the plastic seal encasing her.

The exercise put on Wednesday was just a simulation of the procedures that would be used to evacuate an Ebola patient to Italy. But for Italian military, Red Cross and health care workers, it offered essential experience, especially for those on the front lines of the country's sea-rescue operation involving thousands of African migrants who arrive here every day in smugglers' boats.

U.S. health officials Tuesday laid out worst-case and best-case scenarios for the Ebola epidemic in West Africa, warning that the number of infected people could explode to at least 1.4 million by mid-January — or peak well below that, if efforts to control the outbreak are ramped up.

The widely varying projections by the Centers for Disease Control and Prevention were based on conditions in late August and do not take into account a recent international surge in medical aid for the stricken region. That burst has given health authorities reason for some optimism.

Three more people have died from Legionnaire's disease in Catalonia in northeastern Spain, officials said Tuesday, bringing to seven the death toll from the lung infection in the region in just over a week.

The three deaths took place in Ripollet, a town near Barcelona, Catalonia's health department said.

A simple breath test may one day show whether someone has a strain of tuberculosis that will respond to a frontline antibiotic, or a drug-resistant type, scientists said Tuesday.

Building on previous work for a fast-track breath test, their new prototype technique looks for traces of nitrogen gas emitted by the disease-causing germ Mycobacterium tuberculosis.

U.S. soft-drinks giants Tuesday promised to work to reduce the country's beverage calorie consumption by 20 percent by 2025 in a campaign to counter obesity trends.

Coca-Cola, PepsiCo and Dr. Pepper Snapple pledged to provide smaller-sized bottles, and more water and other low- or no-calorie beverages, to the market to help bring down per-person consumption of their high-sugar drinks.

Fewer than a quarter of U.S. children prescribed medication for attention deficit hyperactivity disorder (ADHD) get the recommended behavioral therapy along with it, said a study out Monday.

The findings in the Journal of the American Medical Association (JAMA) Pediatrics examined records of more than 300,000 children from 1,516 counties across the United States who had received an ADHD prescription.