Health officials say tick-borne diseases rising

Published 12:41 pm Saturday, May 7, 2011

ST. PAUL — Minnesota health officials on Friday urged residents to protect themselves against ticks after the number of tick-borne diseases rose to record levels in 2010.

The Minnesota Department of Health said Friday there was a significant increase in the number of anaplasmosis cases last year, more than double what the department had been seeing in recent years.

Anaplasmosis is one of three diseases carried by the blacklegged tick, formerly known as the “deer tick.” The health department reported about 30 percent of the 720 anaplasmosis patients in 2010 required hospitalization. One person died.

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State epidemiologist Dave Neitzel said the number of anaplasmosis cases was rivaling Lyme disease in some areas of the state. In Aitkin, Beltrami, Carlton, Cass, Crow Wing and Hubbard counties, those cases exceeded Lyme disease cases in 2010.

The number of anaplasmosis disease cases rose more than 20 percent from 2009, but still trailed the nearly 1,300 reports of Lyme disease.

Besides anaplasmosis and Lyme disease, the other common disease carried by the blacklegged tick in Minnesota is babesiosis, of which there were 56 cases in 2010. That’s up from 31 cases in 2009. Nearly half of the babesiosis cases required hospitalization and one person died.

The most common symptoms of the both anaplasmosis and babesiosis are fever, fatigue and muscle ache, with anaplasmosis characterized by its sudden onset. Lyme disease is known by the rash near the bite.

The increase in tick-borne illness is likely the result of expanded suitable tick habitats across the state, Neitzel said. Ticks require a hot, humid climate and small mammals or deer to feed on. Rather than harm the ticks, the thick layer of snow that covered the ground this winter actually provided insulation and helped tick survival, Neitzel said.

The upshot in illnesses could also be the product of more testing by doctors and using better methods, he said.

The department is stressing the use of DEET- or Permethrin-based repellents. People who’ve been in the woods recently should check themselves thoroughly when they return, as it takes between one and two days for the tick to attach before it bites.

“The quicker you get them off of you the better,” Neitzel said.

It’s not only blacklegged ticks people need to worry about. American dog ticks, or “wood ticks,” have caused Rocky Mountain spotted fever in rare cases, Neitzel said.