Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:
U.S. Adult Smoking Rate Falls
The number of American adults who smoke fell to 18 percent in 2011, according to the Centers for Disease Control and Prevention.
The adult smoking rate had been declining for decades but then seemed to level off at about 20 to 21 percent before falling to 19 percent in 2011, the Associated Press reported.
The latest findings are from a survey of about 35,000 adults. The smoking rate was 9 percent among people ages 65 and older but about 20 percent for younger adults. Men had a higher smoking rate than women.
The survey did not include teens, but a previous CDC study found that about 16 percent of high school students were smokers in 2011, the AP reported.
Factors that may have contributed to this latest decline in adult smoking include more public smoking bans, higher state and federal tobacco taxes, and increased spending on prevention and cessation programs, according to Patrick Reynolds, executive director of the Foundation for a SmokeFree America.
"This is a real decline in smoking in America. I'm ecstatic about it. It's proof that we are winning the battle against tobacco," he told the AP.
Smoking is the leading cause of preventable illness and death in the U.S.
Swimmers Warned About Deadly Amoeba
Swimmers in Florida are being advised to avoid stagnant water that could contain a type of amoeba that can cause a potentially deadly brain infection.
Naegleria fowleri is invisible to the naked eye and can be found in warm, standing water, according to an alert issued by the Florida Department of Health. It said that the amoeba is usually harmless, but can cause a fatal brain infection if inhaled through the nose, ABC News reported.
"Wear nose clips, hold your nose shut or keep your head out of the water when swimming, jumping or diving in any freshwater," the health department advised. "Closing your nostrils may reduce your chance of becoming infected."
Infections caused by N. fowleri are extremely rare but almost always result in death. Between 1962 and 2012, 128 people in the United States were infected and only one survived, according to the Centers for Disease Control and Prevention.
The amoeba was linked to the death of a Minnesota child last summer and killed four people in Virginia, Florida, Kansas and Louisiana in 2011, ABC News reported.
Spraying Begins in Dallas to Control West Nile Virus
Spraying is being conducted in North Texas after health officials detected a large increase in the type of mosquito that primarily carries West Nile virus.
The region was at the center of a national outbreak last year that resulted in the country's highest annual death toll from West Nile virus, the Associated Press reported.
In Dallas, trucks will spray through early Wednesday morning in neighborhoods where tests have revealed a rise in the species of mosquito most likely to transmit the virus.
There are no confirmed cases of West Nile in either Dallas or Dallas County and the spraying is being done to stem any outbreak, Crystal Woods, with the Dallas division manager for mosquito control, told the AP.
Drug Makers Can be Sued Over Deals to Delay Generic Drug Sales: U.S. Supreme Court
Makers of brand-name drugs can be sued for violating U.S. antitrust laws if they pay a potential competitor to delay selling generic versions of the drugs, the Supreme Court ruled Monday in a 5-3 decision.
The court said that a "large and unjustified" payment to settle a patent dispute over generic drugs can trigger an antitrust claim against the maker of the brand-name drug, the Los Angeles Times reported.
So-called "pay-for-delay" deals between brand-name and generic drug makers cost consumers and health plans $3.5 billion a year, according to the Federal Trade Commission.
Monday's ruling is expected to lead to lower drug prices for consumers, the Times reported.