West Nile Virus and
By Douglas MacQueen, MD
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?
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?
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
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
Is West Nile
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?
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.