Here's a look at some of the top health news being talked about around the U.S. and the world today:

• Many doctors are reluctant to turn in their colleagues when they recognize one is incompetent, according to a new study. Reported by Reuters, the study - based on self-reporting surveys - found one in three doctors had known at least one fellow doctor who they believed was unfit to practice, but those doctors did nothing.

• Watch out, women with a pear-shape. The areas of the body where a woman gains weight as she ages may play a role in how well her memory holds up, according to new research. Women who gained the most weight around their hips appeared to fare worse than those who gained around the mid-section, CNN reported.

• Officials are concerned about a resurgence of dengue fever in the continental U.S. after a survey of Key West residents showed a growing number of illnesses there, the Los Angeles Times reported. Dengue fever is the most common mosquito-transmitted disease in the world and usually brings high fever, widespread rash, headache, fatigue and muscle aches.

Tina Reed covers health and the environment for AnnArbor.com. You can reach her at tinareed@annarbor.com, call her at 734-623-2535 or find her on Twitter @TreedinAA.