West Nile Virus and Lyme Disease

By Douglas MacQueen, MD

There are currently two zoonotic diseases making the news, West Nile virus and Lyme disease. A zoonotic disease is one that can be passed from animals to humans.

How prevalent are West Nile virus and Lyme disease in upstate New York?

Right now West Nile virus is most active in the Midwest and South. The number of reported cases of West Nile virus in New York is very low this year, most of them in New York City. By contrast, Lyme disease is quite common in this region.

How do West Nile virus and Lyme disease spread?

Both diseases are transmitted to people when an insect feeds on the blood of a small mammal or bird that is infected, and then feeds on the blood of a human being. West Nile is a virus that is spread by mosquito bite. Lyme disease is a bacterial infection that is spread by deer ticks.

Do all ticks carry Lyme disease?

Only deer ticks transmit Lyme disease but not all deer ticks carry the bacteria. Deer ticks are significantly smaller than the common dog tick, which does not carry Lyme disease. A deer tick must be attached to you for about thirty-six hours in order to transmit Lyme disease. If you discover a deer tick that is still flat looking, there is little risk of infection. However, if you remove a deer tick that is fully engorged with blood, there is a chance it could have infected you with the Lyme bacteria.

What is the best way to remove a tick?

Carefully take hold of the tick with a pair of tweezers as close as possible to the place where its head meets your skin. With a slow, steady motion gently pull it out. Some people will quickly develop a red itchy bump where they’ve recently removed a tick. This is not Lyme disease, but an allergic reaction to the tick’s saliva.

What are the symptoms of Lyme disease?

The early symptoms are fever, chills, low energy, and body aches.  They are often accompanied by a round red rash anywhere on the body, including the head, groin, and armpits. It is not painful or itchy, but can increase in size and in some cases the center clears out, resembling a bulls-eye. It’s important to see your doctor if you have these symptoms.

Is Lyme disease curable?

Yes, Lyme disease is completely curable at any stage of the illness with a course of antibiotics, though early treatment is best. It is important to note that the diagnosis of early Lyme disease is based on symptoms, and not on a blood test. Early in the course of the disease a blood test for Lyme disease will come back negative, even if you have been infected.

What if I don’t get early treatment?

If Lyme disease is not treated right away, the initial symptoms go away; however, fever, aches, and fatigue may return later on. At this point, the Lyme test will be positive. Untreated over an extended period of time, Lyme disease can cause heart rhythm problems, arthritis in the large joints, meningitis, and Bell’s palsy. However, even at this stage Lyme disease is 100 percent curable, despite the common misconception that it is incurable if not treated early. Having Lyme disease in the past gives you no protection against a future Lyme infection, so you can get it again.

Is West Nile disease curable?

There is no treatment for West Nile virus, but in most cases, the body’s immune system eliminates the infection. Eighty percent of people who get it have no symptoms, while the remaining 20 percent develop flu-like symptoms. Less than 1 percent of infected people will develop severe disease and need to be in the hospital for supportive care.

How do I protect myself from these two illnesses?

Remove containers with standing water to eliminate mosquito breeding sites and wear insect repellent, particularly at dusk, to avoid mosquito bites. To protect against Lyme disease, wear long sleeves and long pants when walking in the woods or brush, tucking them into your socks for better coverage.

Dr. MacQueen is an infectious disease specialist who is board certified in internal medicine. He is on the medical staff of Cayuga Medical Center and can be reached at the Cayuga Center for Infectious Diseases at (607) 241-1118.

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