NewsDesk @bactiman63

Washington state health officials are reporting the first locally acquired human case of the tick-borne disease anaplasmosis in a Washington resident discovered on August 8. A Whatcom County man in his 80s was hospitalized with severe disease, and is now in recovery, after working in the brush in Mason County where he was likely bitten by an infected tick.

Ixodes pacificus
Image/CDC

Human cases of anaplasmosis have been identified in Washington before, though all previous cases involved travel outside of the state. Until now, only dogs have been diagnosed with locally acquired anaplasmosis in Washington.

Anaplasmosis is caused by bacteria carried by infected ticks. Symptoms include fever, headache, malaise, and body aches. Anaplasmosis can be a serious illness if not treated with antibiotics promptly and correctly.

In Washington, the disease is spread by the western blacklegged tick (Ixodes pacificus) which are mainly found in the western part of the state as well as along the eastern slopes of the Cascades. Western blacklegged ticks infected with Anaplasma spp. bacteria, which causes the disease, have previously been found in Washington at very low levels.

“Not all tick bites will cause disease,” said Scott Lindquist, MD, MPH, State Epidemiologist for Communicable Diseases. “However, people across Washington are at risk for tick-borne illnesses and should take precautions to prevent tick bites.”