Higher levels of pesticide residue in fruit and vegetables are associated with lower quality of semen, according to a study published on Tuesday.

Its authors said the research was only an early step in what should be a much wider investigation.

An American healthcare worker who contracted the dangerous Ebola virus while working in Sierra Leone has improved and is now listed in fair condition, hospital officials said Monday.

The man, whose identity has not been revealed, "has improved from serious to fair condition," said a statement from the National Institutes of Health Clinical Center.

Children of richer, better-educated parents have bigger brains and more cognitive skills than their less-fortunate peers, but social help and teaching can help to overcome the differences, a study published on Monday said.

The distinctions were most profound in regions of the brain supporting language and reading, executive functions like memory and decision-making, and spatial skills, experts in the United States reported in the journal Nature Neuroscience.

Nine Indonesian men have died after consuming alcohol mixed with mosquito repellent, police said Monday, the latest deaths in the country linked to tainted drinks. 

The men bought the drinks on the street in the city of Prabumulih on Sumatra island on Thursday and were admitted to local hospitals after falling ill, local police spokesman Djarod Padakova told Agence France Presse. 

Sierra Leoneans were once again allowed to leave their homes Sunday evening after the government announced the end of a three-day nationwide lockdown aimed at preventing a resurgence of the deadly Ebola virus.

During the curfew period -- which was ordered by President Ernest Bai Koroma and ran from 0600 GMT on Friday until 1800 GMT Sunday  -- some 26,000 volunteers went door-to-door to check for sick people and raise awareness about the disease.

U.S. President Barack Obama on Friday rolled out plans to cut inappropriate antibiotic use by half, in an effort to tackle drug resistance.

According to the Centers for Disease Control and Prevention, drug-resistant bacteria, also known as "superbugs," kill 23,000 people a year in the United States.

A British army reservist who contracted Ebola while working as a volunteer nurse in Sierra Leone has fully recovered after becoming the first patient in the world to receive an experimental new treatment.

Anna Cross, 25, was discharged on Friday from the Royal Free Hospital in London where she was taken earlier this month after being evacuated from west Africa on a military plane.

Indiana Gov. Mike Pence overrode state law and his own anti-drug policies Thursday to authorize a short-term needle-exchange program designed to help contain HIV infections in a rural county where more than six dozen cases have been reported, all of them tied to intravenous drug use.

Pence issued an executive order declaring a public health emergency in Scott County, an economically depressed area about 30 miles north of Louisville, Kentucky, that has seen 79 new infections since December. The county typically sees only about five HIV cases each year, health officials said.

A Cambodian court on Friday sentenced three people to between 10 and 15 years jail for organ trafficking, after they persuaded poor Cambodians to sell their kidneys to wealthy compatriots undergoing dialysis in Thailand.  

The convictions were the first for organ trafficking in the impoverished Southeast Asian nation.

Two experimental Ebola vaccines, tested in Liberia on more than 600 people in a phase 2 clinical trial appear to be safe, the U.S. National Institute of Allergy and Infectious Diseases (NIAID) said Thursday. 

The results confirm two clinical trials, each with some 20 people, that were carried out earlier in the United States.