Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:
Three-Week-Old Boy Receives Heart Transplant
A baby boy in California is recovering well 2 weeks after he received a life-saving heart transplant when he was just 3 weeks old.
Dravyn Johnson, of Orange County, was born with a severe heart defect and was transferred to Mattel Children's Hospital UCLA when he was just a few days old. It was impossible to repair his heart, so surgeons put him on the transplant list, CBS News reported.
A new heart -- the size of strawberry -- became available sooner than expected and Dravyn became the youngest heart transplant recipient at UCLA in 25 years.
He was released from the hospital on Wednesday and is spending his first day at home. He will require follow-up appointments and is expected to remain on medications. Doctors said his new heart should last 20 years before he'll need another transplant, CBS News reported.
Deaths From Extreme Cold Highest in Rural Areas of Western U.S.
The rate of cold-related deaths in rural areas of the western United States is much higher than in other regions of the country, according to a new study.
Centers for Disease Control and Prevention researchers analyzed more than 5,800 cold-related deaths that occurred nationwide from 2010 to 2013. The cold-related death rate was 20.5 per million in rural areas of the western U.S., compared with 4.5 to 7.8 per million in other rural regions.
Cold-related death rates in urban areas ranged from 2.9 to 5 per million, according to the study in BMJ.
Many rural counties in the western U.S. have high poverty rates, the researchers noted. An earlier CDC study found an increased risk of cold-related death among people who lived in areas with rapid temperature changes, large shifts in nighttime temperatures, and at high elevations.
Previous research has shown that the risk of cold-related death is highest among older adults, infants, men, blacks, and people with chronic health problems such as heart and lung diseases.
The study also found that weather-related deaths from extreme heat and cold, storms, and floods, can be up to seven times higher in low-income counties than in high-income counties.
Tulane Lab Worker Tests Positive for Deadly Bacteria
A lab worker is the first person to test positive for a deadly bacteria that escaped a primate research laboratory, a Tulane University spokeswoman says.
Initial blood tests from the animal clinic employee at the Tulane National Primate Center in New Orleans showed current or prior exposure to burkholderia pseudomallei bacteria, ABC News reported.
However, the levels of antibodies to the bacteria were so low they were within levels that sometimes occur among members of the public with no exposure to the bacteria, and the worker showed no symptoms, Tulane officials said.
The Centers for Disease Control and Prevention will conduct further tests to confirm the initial results.
At least eight monkeys at the primate center initially tested positive for the bacteria, which is more commonly found in Southeast Asia and Northern Australia, ABC News reported.
A federal investigator also tested positive for exposure to the bacteria, but it wasn't clear if the exposure occurred at the primate center or when the investigator visited an infected region, the CDC said.
New Type of Artificial Heart Could Offer Permanent Replacement For Failing Hearts
A new type of artificial heart that propels blood through the body instead of pumping it could offer the first permanent mechanical replacement for people with failing hearts, according to the researchers working on the device.
Because of the heavy workload, an artificial heart that uses many moving parts to pump blood would quickly wear out, Dr. William Cohn, chief medical officer of BiVACOR, told ABC News.
But there is only one moving part in the bionic heart being developed by BiVACOR, which is headquartered at the Texas Heart Institute in Houston.
"The device has performed in many respects better than any artificial heart anybody has come up with in the last 50 years," Cohn told ABC News.
He and his colleagues consider it the "first legitimate shot on goal for a permanent mechanical replacement for the failing human heart," he added.
Most Listeria Outbreak Wrongful-Death Lawsuits Settled
Most of the wrongful-death lawsuits arising from a deadly listeria outbreak in 2011 have been settled. The outbreak that killed 33 people and sickened more than 140 others was traced to a cantaloupe farm in Colorado.
On Wednesday, a Denver District Court judge approved settlements for relatives of 30 of the people who died. The families sued companies that handled or sold the melons, the Associated Press reported.
In addition, lawsuits by 20 people who became ill in the outbreak were settled.
Details of the proposed settlements are confidential, said plaintiffs' attorney Bill Marler, who noted that medical expenses from those cases were more than $12 million, the AP reported.