Pennsylvania officials are warning residents that there is now a danger of Lyme disease in every county in the commonwealth.
Department of Environmental Protection researchers say that blacklegged deer ticks have now been observed in all 67 Pennsylvania counties, the first time that has happened.
The ticks are the primary carrier of the disease that can cause fever, fatigue, headache, muscle aches and joint pain.
In recent years, the tick has become embedded in western Pennsylvania, although the rate of Lyme disease is lower there than in the rest of the commonwealth.
Pennsylvania has reported the most cases of Lyme disease in the nation for the past five years.
Officials say parents should check children for ticks, and showering within two hours of outdoor exposure may also help prevent transmission.