Lyme disease cases increasing in N.H.

New Hampshire health officials are warning people to take precautions against ticks after new data showed a dramatic increase in the number of cases of tick-borne Lyme disease in the southeast part of the state.

Half of the reported cases of Lyme disease in New Hampshire last year were in Rockingham County, according to the state's data.

Lyme disease, which is transmitted to humans by the bite of infected ticks, causes more than 20,000 infections in the United States each year, according to officials.