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When spring comes, so do tick-borne diseases

A blacklegged tick (deer tick) nymph.1 / 3
A blacklegged nymph, adult female and larvae.2 / 3
A common wood tick.3 / 3

According to David Neitzel, "bug expert" at the Minnesota Department of Health Acute Disease Investigation and Control program, once the snow melts, out come the ticks and, with them, diseases like Lyme disease, human anaplasmosis, babesiosis, ehrlichiosis, Powassan encephalitis, and Rocky Mountain spotted fever. Reports of deer ticks are already coming in from nearby counties and northern Minnesota.

Recent years have shown an increase in tick-borne diseases. Over 1,200 cases of Lyme disease - the most commonly seen tick disease - were reported in Minnesota in 2011 with 17 in Goodhue County residents, up from seven in 2010. Lyme diseases numbers were down a bit in 2012 (872) likely due to the hot, dry summer.

Lyme disease is spread from the blacklegged tick, also called deer tick, which is commonly found in wooded areas. Only the immature nymphs or adult females can transmit disease. Adults are more active in the fall. Nymphs hatch in early spring and start looking for a warm animal or person to feed on. Because they are so tiny, it's important for people to check and recheck for them when out in the woods.

The adult female has a reddish-orange back. It can be distinguished from a wood tick, which is larger and has white markings on its back. Wood ticks are common in spring and early summer.

Ticks can be avoided by tucking pants into socks or boots and using a repellent with DEET or permethrin. Wearing light-colored clothing will make ticks easier to see.

To remove ticks, use a tweezers to grasp the tick close to its mouth and gently and slowly pull it out, then apply an antiseptic to the bite. Do not burn it off or use petroleum jelly.

Prompt removal of attached ticks prevents disease.

Not all people bitten by a deer tick will get a disease, and not all ticks carry diseases.

If a deer tick is infected, it must be attached for at least 24 hours before it can transmit a disease.

Lyme disease is easier to treat if recognized early. Symptoms appear within three to 30 days and include a skin rash that has a bull's-eye appearance (although not everyone gets the rash), fever and chills, tiredness, muscle or joint pain. Other conditions can occur later such as facial paralysis, irregular heartbeat, weakness, numbness or pain in arms and legs, memory problems or arthritis in joints, usually the knees which may be swollen and painful.

A doctor can diagnose Lyme disease by symptoms and a blood test and treat it with antibiotics.

Two diseases which are less common than Lyme disease - human anaplasmosis and babesiosis - can also be transmitted by the deer tick. Symptoms include high fever, muscle aches, chills, severe headache, and sometimes nausea, vomiting, cough and aching joints. Sometimes patients have no symptoms. Treatment is with antibiotics.

In 2012 471 cases of anaplasmosis and 37 cases of babesiosis were reported. Rocky Mountain spotted fever, Powassan encephalitis and ehrlichiosis are less common in Minnesota.

Mosquitoes, too

When things warm up during summer months, mosquitoes become the next vector of diseases like West Nile virus, La Crosse encephalitis, Western equine encephalitis and Eastern equine encephalitis.

Mosquitoes look for standing water sources for breeding. The tree-hole mosquito, which causes La Crosse encephalitis, gets its name from the crooks in trees where water is held, but other things that hold water also will increase their habitat, such as old tires, pots, buckets, etc.

Symptoms can vary from fever and headache to seizures, coma, and death. Over 60 cases were confirmed in Minnesota counties along the Mississippi River since 1985, 13 in Goodhue County.

West Nile virus first appeared in the U.S. in 2002 and was identified in birds, horses, and humans. Often, people who get West Nile virus have no symptoms. Of the 70 cases confirmed in Minnesota in 2012, 51 percent had fevers, 49 percent had encephalitis or meningitis, and one died. No cases were reported in Goodhue County.

These mosquitoes are most often seen mid-July to mid-September in western and southern agricultural areas in Minnesota.

While the number of mosquitoes that are actually capable of causing infection in humans is relatively small, but it is always advisable to take preventive measures to protect yourself.

• Wear mosquito repellent containing up to 30 percent DEET (10 percent for children).

• Wear long sleeve shirts and pants.

• Avoid outdoor activity at peak mosquito feeding times (dawn and dusk).

• Eliminate water-holding containers (buckets, tires, etc.) from your property.

This will reduce numbers of several mosquito species.

-- Vicki Iocco is a public health nurse in charge of the Goodhue County Health and Human Services Disease Prevention & Control Program.