"TICKs" The Season
Tuesday 21st of February 2017
Tick season is here. It's always here. Whether you're taking a
nice walk in a park or hiking with the grandkids through the woods,
it's better to be aware and take precautions. Well, here they are -
Ticks are bloodsucking external parasites that feed on humans, wild
and domestic mammals, birds, reptiles and others. They are totally
dependent on the blood/tissue fluids of the host.
Ticks are second only to mosquitoes as transmitters of infectious
agents to humans. The longer an infective tick feeds, the greater
the chance of infection.
Ticks are not insects. Insects have 6 legs as an adult and three
body segments, whereas, ticks have 8 legs as an adult and two body
segments. Ticks are arachnids, as are chiggers, spiders, and mites.
A hard tick seeks a blood meal at ground level by climbing onto
vegetation and using their forelegs to feel/grab for a host. Ticks
are usually found from ground level to 3 feet above the ground. A
tick uses carbon dioxide, scent, body heat, and other stimuli to
find a host.
When ticks feed they cut the skin with their mouthparts, insert
their mouthparts into the wound, use their "teeth" to cut blood
vessels under the skin (causing blood to pool), inject anti-clogging
agents into the host, and suck the victims blood.
Ticks have four life stages: egg, larva, nymph, and adult. The
larva, nymph, and adult are called ''active" stages. The egg hatches
into a larva. A larva (''seed'' tick) has 6 legs. It feeds and molts
(shedding its cuticle) into a nymph. The nymph has 8 legs and no sex
differentiation. It feeds and molts into an adult. The adult is
differentiated into male or female. The female requires a blood meal
in order to lay eggs.
Many tick life cycles are completed within one to two years.
However, depending on the ease or difficulty of finding a blood
meal, ticks may require only a few months or as long as three years
to pass through all stages.
Taking the following actions will reduce ticks on property.
Ticks are susceptible to dehydration. You can reduce humidity in
property by: pruning trees, clearing brush, removing litter, mowing
grass, and letting grass dry thoroughly between waterings. Also,
move the shrubby overgrowth between the lawn and woods father away
from areas frequented by people and pets.
Modify your property so that it is unattractive to animals that are
hosts to ticks by: eliminating birdfeeders, birdbaths and
salt-licks; erecting fencing around the property; clearing away
wood, garbage, and leaf piles; and removing stonewalls.
Directly kill ticks that live on the property by applying acaricides
(tick-killing chemicals). Acaricides include: cyfluthrin,
chlorpyrifos, and carbaryl. Granular and liquid sprays are
Modify outdoor areas: widen trails, stay in the center of paths, and
move playscapes to safe areas.
Avoid tick infested areas, whenever possible.
Wear light-colored clothing. This allows you to more easily see
ticks on your clothing.
Wear a long-sleeved shirt and long pants. This reduces the skin area
exposed to ticks.
Tuck your shirt into your pants and pants into your socks. This
keeps ticks on the outside of clothing as they crawl upwards.
Use EPA-approved tick repellents. Wash off repellents when you
Conduct frequent tick-checks. This includes a visual inspection of
the clothing and exposed skin, followed by a naked, full-body
examination in a private location.
Avoid sitting on the ground.
Also check your pets, especially around the ears or eyes.
Vaccine trials to prevent LD are currently underway.
Tick's mouthparts have harpoon-like barbs that are designed to
penetrate and maintain attachment to the skin. Ticks secrete a
cement-like substance that helps them adhere to the skin. For these
reasons ticks often are firmly attached to humans and animals.
1. Using a fine-point-tweezer, grasp the tick's mouthparts (place of
attachment) as close to the skin as possible.
2. Gently pull the tick straight out with steady pressure.
3. Place the tick in a small vial, label with the date & your
name/address; send for testing, if available.
4.Wash your hands. Disinfect the tweezers and the bite site.
5. Contact your doctor.
Children should be told to seek adult help for tick removal.
It is better to wait and correctly remove the tick with a
fine-point-tweezer than to pull the tick off with your fingers.
If you must remove the tick with your fingers, use a tissue or leaf
to avoid contact with potentially infected tick fluids.
Do not prick, crush or burn the tick, as it may cause the release of
infected tick fluids.
Do not try to smother the tick (e.g. petroleum jelly, nail polish)
as the tick has enough oxygen to complete feeding.
TICK TRANSMITTED DISORDERS
This is a malaria-like infection caused by protozoa, Babesia spp.,
that parasitize red blood cells. There are several species in the
East and a newly described species from the western U.S. The first
U.S. case report of babesiosis in a human was from Nantucket Island,
MA in 1969. Immunosuppressive may occur during this disease.
Symptoms: fever, chills, fatigue, headache, muscle pain, and a
breakdown of red blood cells (hemolytic anemia). Laboratory
confirmation is based on identifying the parasite within red blood
cells or on a positive antibody titer. Subclinical chronic infection
does occur and a negative blood smear does not exclude infection.
This disease is more severe (sometimes fatal) in elderly people and
those who have had their spleens removed. Treatment is with
clindamycin with oral quinine. Extremely ill patients may benefit
from a blood transfusion.
Transmission: The black-legged & western-legged ticks.
COLORADO TICK FEVER
This is a viral disease of short duration and low mortality that
occurs in the western U.S. Between 200-300 cases are voluntarily
Symptoms: sudden onset of fever, chills, severe headache, muscle
aches, and occasionally, a faint rash, which lasts about a week.
After a 2-3 day remission, symptoms, accompanied by a drop in white
blood cells, may recur. Complications include encephalitis and
severe bleeding. Diagnosis is assisted by serologic testing.
Treatment is with analgesics and supportive therapy.
Transmission: Rocky Mountain wood tick.
EHRLICHIOSIS (HME & HGF)
The various forms of human and animal ehrlichiosis are caused by
rickettsiae (intracellular parasites). The first case of
ehrlichiosis was described in dogs in Africa in 1935. In 1986 the
first U.S. acquired human disease was described. This human
infection was named human monotypic ehdichiosis (HME) and is caused
by Ehdichia chaffeensis. Most cases are reported from the South
Central and Southeastern U.S. A rash occurs in a small percentage of
people. A related variation, called human granulocytic ehrlichiosis
(HGE), was described in 1994. HE is the human disease caused by E.
equi, the cause of ehrlichiosis in horses. It has been found in AK,
CA (serology), CT, FL, GA, MA. MD, MN, NY, PA, RI, TN, and WI.
Separate tests are required for each disease, Coinfection with LD
varies, but 9% to 21% is the average. Persisting infection can
Symptoms: fever malaise headache chills, severe muscle aches & pain,
vomiting, anemia, lung infection
abnormal decrease in white & red blood cells, decrease in platelets,
or elevated liver enzymes. Sometimes
symptoms are nonspecific. Laboratory diagnosis is made by testing
acute and convalescent serum. Delayed treatment can result in death.
Treatment is with tetracycline/doxycycline.
HME - probably the lone star tick.
HGE - probably the black-legged tick.
Worldwide there are over 850 tick species, about 100 of which are
capable of carrying diseases. In the U.S. four genera, Amblyomma,
Dermacentor, Ixodes and Ornithodoros transmit to humans the vast
majority of diseases caused by bacteria, viruses, protozoa, and
LYME DISEASE (LD)
LD is caused by the bacterium Borrelia burgdorferi. The disease was
first described in European literature over 100 years ago. The
causative agent was discovered in 1981 byWilly Burgdorfer, Ph.D.,
M.D.(Hon). New Borreliastrains causing Lyme-like symptoms have
recently been discovered in various parts of the world. There are
over 300 strains of this bacterium in the U.S. alone. Coinfections
can make LD worse.
Symptoms: initially are flu-like (fever, headaches muscle aches and
pain), with or without a centrifugally expanding rah that has
lighter and darker rings of discoloration called erythema migrant (EM).
Later symptoms include multiple rashes, joint swelling, joint pain,
lossof reflexes, cranial nerve palsies (e.g. facial or oculomotor
paralysis, loss of smell or taste, swallowing problems visual
disturbances), cognitive or behavioral changes, disorder of the
peripheral nerves, head conduction defects, stroke and inflammation
of various parts of the eye. Serologic tests cannot be relied upon
for diagnosis. Treatment is with various antibiotics. It is
recommended treatment on tick-bites under certain conditions. Some
people have ongoing symptoms, which may be due 10 persisting
infection or the triggering of an autoimmune reaction.
Transmission: Transmitted primarily by the black-legged tick in the
eastern and mid-U.S. and by the western black-legged tick in the
ROCKY MOUNTAIN SPOTTED FEVER (RMSFI)
RMSF, also called tick-borne typhus, is caused by Rickettsia
rickettsii and was first identified in 1873. The disease is reported
from all over Noah America but is most prevalent in the eastern U.S.
Symptoms: sudden onset of flu-like aches and pain headache, chills,
confusion, light sensitivity and high fever. A reddish-to-black rash
(resembling measles) stabs on the extremities (e.g., wrists and
ankles) and may spread to the entire body. Death can occur.
Serologic tests will not be positive until 10-14 days after onset.
Therefore, doctors must make a clinical diagnosis and treat early,
as the main cause of death is delayed treatment or improper use of
antibiotics. The treatment is either tetracycline/doxycycllne or
Transmission: American dog tick, Rocky Mountain wood tick, and
Pacific Coast tick. All stages of ticks can transmit the pathogen.
Transmission can occur within a few hours of feeding.
TICK TRANSMITTED DISORDERS
TICK-BORNE RELAPSING FEVER
This is a multisystem disease caused by the spirochetes Borrelia (B.)hermsi,
B. turicata, and B. parked. In North America the disease occurs
primarily in the western U.S.
Symptoms: repeating bouts of fever lasting 2-9 days alternating with
afebrile periods. Additional symptoms include sudden onset of fever,
chills, headache, muscle and joint pain. Laboratory diagnosis is
most often made by detecting spirochetes in peripheral blood smear
taken during febrile episodes. Laboratory tests are available.
Treatment is with penicillin or tetracycline/doxycycline.
Transmission: The pathogen is transmitted by soft ticks Ornithodoros
hermsi, 0. turicata and rarely 0. parked, and can be transmitted
transovarially from the female to her eggs. 0. hermsi, O. turicata
tick feed mainly at night and can transmit the spirochete within
This is a potentially fatal reaction to a paralyzing toxin secreted
in thesaliva of feeding tick. Tick paralysis occurs in Europe, Asia,
Africa, Australia, and North America This :condition causes injury
or death to thousands of animals each year. The condition was first
recognized in Australia in 1824 The first North American case was in
British Columbia in 1912.
Symptoms: headache, vomiting, general malaise loss of motor function
and reflexes, followed by paralysis that starts in the lower body
(especially the legs) and spreads to the rest of the body. This can
cause respiratory failure and Oath. Death in young children can
occur in one or two clays. Temperature and blood chemistry are
usually normal. Treatment is to remove the tick.
Transmission: A wide variety of ticks can cause the condition
Important vectors In North America include: the American dog tick
and the Rocky Mountain wood tick. The black-legged tick can also
pause this condition. While feeding larva and nymphs can cause
paralysis in laboratory tests, the majority of naturally occurring
cases involve feeding female ticks. Male ticks appear not to cause
TULAREMIA (rabbit fever)
The bacterium Francisella tularensis causes tularemia. This disease
was identified in 1911 and in North America is found primarily in
the south central U.S. However, cases are reported from almost every
Symptoms: repeated spikes of severe fever local skin ulcers enlarged
lymph nodes, conjunctivitis and/or pneumonia. Laboratory diagnosis
is often based on antibody test. The disease is treated with
Transmission: Lone star tick, Rocky Mountain tick, Pacific Coast
tick, American dog tick, black-legged tick, horseflies, deerflies,
and contact with infected animals or infected water. Most cases in
the south central U.S. are caused by tick-bites. Most cases in the
rest of the country are primarily due to contact with infected