Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:
Joan Rivers Suffers Cardiac Arrest
Comedian Joan Rivers was rushed to Mount Sinai hospital in New York City Thursday morning after suffering cardiac arrest, according to law enforcement officials.
Rivers, 81, was found unconscious and unresponsive by emergency workers who responded to 201 East 93rd St. at 9:40 a.m., The New York Times reported.
That is the address of an outpatient care facility called Yorkville Endoscopy. ABC and other news organizations reported that Rivers was having vocal cord surgery at the facility.
On Twitter, E! network's Ken Bake said Rivers was in stable condition, The Times reported.
Brain-Eating Amoeba in Louisiana Parish Water System
The presence of a brain-eating amoeba has been confirmed in the water supply of a Louisiana parish, officials say.
The Naegleria fowleri amoeba was found in the water system of St. John the Baptist Parish. The system supplies water to more than 12,000 people in three towns, ABC News reported.
If contaminated water travels through the nose to the brain, the amoeba can cause a deadly form of meningitis. Drinking contaminated water poses no threat, according to the Louisiana Department of Health and Hospitals.
There have been no reports of infections from the amoeba in the parish, and the source of contamination has not been identified. Extra high levels of chlorine will be flushed through the water system for 60 days to kill any amoeba, ABC News reported.
Many Parents Uncomfortable About Kids Playing Football: Poll
Nearly half of American parents are uncomfortable about their children playing contact sports such as football and hockey amid growing concerns about the long-term effects of concussions.
A new poll found that 44 percent of parents weren't comfortable with their children playing football, the same percentage was uncomfortable with their children playing ice hockey, and 45 percent had doubts about wrestling, the Associated Press reported.
However, only five percent of the 1,044 adults who took part in the AP-GfK poll said they discouraged their youngsters from participating over the last two years.
Most of the parents said they were comfortable with their children taking part in other types of sports such as baseball and softball, soccer, swimming, track and field, and basketball, the AP reported.
Training for coaches in youth and high school programs has been increased, and helmet makers are offering new products designed to reduce the force of impact, but it's not clear whether these new helmets will be effective.
And despite concerns about concussions, the number of high school students playing football has declined only slighty. Nearly 1.1 million students played 11-man football in the 2012-13 school year, according to the National Federation of State High School Associations. That's down by about 10,000 from the year before and down more than 20,000 since 2008-09, the AP reported.
In related news, a group of American soccer parents and players filed a lawsuit against FIFA and several U.S.-based soccer organizations seeking new safety rules, such as limiting headers for players 17 and younger.
The lawsuit -- which was filed in federal court in San Francisco and does not seek monetary damages -- alleges that nearly 50,000 high school soccer players suffered concussions in 2010, the AP reported.
Along with new safety rules, the lawsuit wants FIFA to permit temporary medical substitutions of players that aren't included in the maximum three player replacements allowed in most FIFA-sponsored games, the AP reported.
"We believe it is imperative we force these organizations to put a stop to hazardous practices that put players at unnecessary risk," said Steve Berman, a Seattle-based lawyer representing the soccer parents and players.
He helped negotiate a recent proposed legal settlement in a case involving the NCAA, which agreed to toughen return-to-play rules for players who suffer head blows. The NCAA also promised to create a $70 million fund to pay for thousands of current and former athletes to be tested for brain trauma, the AP reported.