With summer in full swing, ticks and mosquitoes are out in Borderland. A record number of tick-born illnesses were reported to the Minnesota Department of Health last year. Health officials are warning that prevention of bites is vital in protecting against disease.
Melissa Kemperman, an epidemiologist with the Minnesota Department of Health, said the cause of the record number of cases could be more people being exposed as they do outdoor activities, more infected ticks, or a combination of both.

Tick-borne illnesses
Bites from blacklegged ticks, also called deer ticks, led to a record number of tick-borne disease cases in Minnesota in 2007, according to MDH.
Last year 1,239 Lyme disease cases were reported, up from the previous record of 1,023 cases reported in 2004.
People are at the greatest risk for becoming infected between spring and mid-summer, Kemperman said. Deer ticks are typically found in hardwood forests. In Koochiching County, the swampy areas are too wet for ticks to survive, but they can survive in the county’s upland areas, Kemperman said.
Deer ticks are smaller and darker in color than the common wood ticks that people may encounter this time of year, according to MDH. Deer ticks also don’t have the white markings that the wood ticks have.
Koochiching County is not located in the range where the risk of infected ticks exists, Kemperman said. But over the past few years deer ticks have expanded their range into parts of west-central, northwest and northeast Minnesota, Kemperman said. A few scattered cases have been reported in the area south of the border, she said. Canada has also found some infected tick populations around the Lake of the Woods area.
Not all deer ticks carry the organisms that cause disease. A deer tick needs to be attached for 24-48 hours to transmit Lyme disease bacteria. Not every person who is infected with these organisms will develop symptoms.
People who are infected with Lyme disease often feel like they have the flu, according to the MDH.
Between three and 30 days after a deer tick bite, symptoms may appear that include a distinctive rash, fever, chills, headache, muscle and joint pain and fatigue.
Days to weeks after the onset of the disease, the person may experience multiple rashes, facial paralysis on one side of the face, fever, stiff neck, headache, weakness or numbness in arms and legs, irregular heart beat and persistent weakness and fatigue.
Weeks to months following the onset of the disease, people may experience arthritis in one or more joints, problems with the nervous system and persistent weakness and fatigue.
Lyme disease is treated with antibiotics and is most effective if caught early, according to the MDH.
Deer ticks also carry disease-causing organisms that cause human anaplasmosis and babesiosis, which were reported in record numbers last year. In 2007, 322 human anaplasmosis cases and 24 babesiosis cases were reported to MDH, an increase from 186 human anaplasmosis cases and 18 babesiosis cases reported in 2006.
Symptoms of human anaplasmosis include a fever over 102 degrees, severe headache, muscle aches, chills and shaking. It is treated with antibiotics.
Symptoms of babesiosis are high fever, muscle aches, chills, fatigue, headache and loss of appetite. The symptoms may go away without treatment, but it’s treated with antimicrobial drugs.

West Nile Virus
West Nile Virus is transmitted to people and horses through the bite of an infected mosquito.
One human case of the virus was reported in Koochiching County in 2007. The risk for the virus is lower in the county, but it is not nonexistent, Kemperman said.
People are at risk for being bitten by an infected mosquito between mid- to late-summer and at dawn and dusk, Kemperman said.
About 20 percent of people bitten by an infected mosquito will develop West Nile fever symptoms, according to the MDH. Symptoms of West Nile fever include the sudden onset of a high fever, severe headache, nausea, vomiting, sore throat, backache, joint pain, prominent muscle aches and weakness, prolonged fatigue and a rash.
About one in 150 people infected with the virus will develop a severe illness called West Nile encephalitis, according to MDH. Symptoms of West Nile encephalitis include mental status changes, vomiting, sensitivity to light, altered reflexes, seizures. About 15 percent progress to a coma.
About 10 percent of severe West Nile cases are fatal, according to MDH. Most severe cases are in the elderly.
About 33 percent of horses showing symptoms are put down or die from West Nile infections.

Prevention
Campers, hikers, farmers and people in outdoor occupations are at risk for tick-borne diseases. Repellents containing DEET should be used when outdoors, Kemperman said. Products containing up to 30 percent DEET are safe for clothes or skin and are effective, she said. Permethrin-based products, which are applied to clothing only, can also be used.
When outside, the MDH recommends wearing long-sleeved shirts and long pants tucked into the top of the socks or boots to create a barrier. Wearing light-colored clothes also makes it easier to see ticks.