Tick and Mosquito Infections Spreading Rapidly, C.D.C. Finds

Farewell, carefree days of summer.

The number of people getting diseases transmitted by mosquito, tick and flea bites has more than tripled in the United States in recent years, federal health officials reported on Tuesday. Since 2004, at least nine such diseases have been discovered or newly introduced here.

The Centers for Disease Control and Prevention did not suggest that Americans drop plans for softball games or hammock snoozes. But officials emphasized that it’s increasingly important for everyone — especially children — to be protected from outdoor pests with bug repellent.