Brenda Fitzgerald, the director of the Centers for Disease Control and Prevention, has resigned following a report that she traded tobacco stock while leading the agency tasked with reducing use of tobacco. 

The director of the Centers for Disease Control and Prevention says officials are finding it challenging to eradicate mosquitoes in a part of Miami where 14 people appear to have contracted the Zika virus.

Prescription painkillers should not be a first-choice for treating common ailments like back pain and arthritis, according to new federal guidelines designed to reshape how doctors prescribe drugs like OxyContin and Vicodin.

New details about the possible effects of the Zika virus on the fetal brain emerged Wednesday as U.S. health officials say mosquito eradication here and abroad is key to protect pregnant women until they can develop a vaccine.

U.S. health officials issued guidelines Friday to prevent the sexual transmission of the Zika virus, telling men who have been to outbreak areas to use condoms during sex with pregnant women.

Centers for Disease Control and Prevention officials say a lab technician is being monitored for possible exposure to the Ebola virus.

Federal health officials are significantly expanding the breadth of vigilance for Ebola, saying that all travelers who come into the U.S. from Ebola-stricken West African nations will now be monitored for symptoms of illness for 21 days.

Federal health authorities are telling the nation's hospitals to "think Ebola." CDC Director Tom Frieden is urging hospitals to watch for patients with fever or symptoms of Ebola who have traveled from the three Ebola-stricken African nations in the past 21 days.

Authorities in Dallas are trying to locate a homeless person who might have had contact with the lone Ebola patient diagnosed in the U.S. Dallas County Judge Clay Lewis Jenkins didn't identify the person, whom he described as a "low-risk individual identified as a contact."