Arizona public health officials expect this to be one of the most virulent flu seasons on record. To help individuals track cases of flu and flu-like illness, the Centers for Disease Control has created a new app for some smart phones.

The CDC records and tabulates cases of flu-like symptoms as they are reported by participating doctors. The FluView app makes that surveillance data available to iPhone users.

An image of the United States appears on the opening screen. App users can tap any state to link to public health department web pages.

The app is part of an emerging field of mobile health. Often referred to as "mhealth," it uses mobile technologies to assist, and in some cases transform, health care delivery, research, policy and business.