Tuesday, July 4, 2017

Ticks: Lyme, Anaplasmosis, Babesiosis

From left to right: larvae, nymph, adult male, adult female.
Nymphs and adult females are the vectors for human infection.
Ticks get on your shoes, socks or legs when you brush against
vegetation. Ticks do not drop from above. The CDC website
recommends chemical repellants, also how to do a tick check
and how to wash and dry clothes to kill ticks.
June and July are the prime months for contracting a tick-borne disease. During these months the vector is the nymph stage, which is about the size of a poppy seed. There is a lessening incidence in August, September and further into fall and winter, as the vector becomes the more easily seen adult female tick (the size of a small apple seed), and also because people spend less time outdoors with the onset of colder weather.

An observation here: the term 'bite' is not descriptive. If not detected, a nymph will latch on for 3-4 days for a blood meal before dropping off; adult females stay attached for 7-10 days. Adult males are not on you for a meal. Rather, they are wandering around looking to find and fertilize a female. This meet-and-mate part of the tick's life cycle is the reason that deer are integral to a region harboring a serious tick disease problem. Small mammals (mice, chipmunks, etc.) are vectors for the larval and nymph stages to become infected, but a large mammal species such as deer is essential for the mating and final blood meal that allows the fertilized adult female tick to lay up to 3,000 eggs.    

Lyme, Anaplasmosis and Babesiosis are the big three for New England, but the full count for tick-borne diseases now overtops a dozen. More information on tick-vector diseases can be seen as the Centers for Disease Control website: http://www.cdc.gov/ticks/. The CDC has great information on the tick diseases, and also on practical matters such as how to avoid getting bitten by a tick, and what to do once you have been bitten.

Lyme starts subtle. If the stricken person missed the actual bite, then the first sign is often but not always the signature "bull's eye" rash. Moderate fever, chills, fatigue, muscle ache and a headache may accompany the rash. Only months after the rash and the initial set of symptoms are gone is there a possibility that really bad consequences set in: arthritis, partial facial paralysis, meningitis, limb weakness, and so forth.

Anaplasmosis is not subtle. The symptoms are more akin to being run over by a car, having it circle around to hit you again, and then one more time to park on your head. Some 7 to 10 days after the bite the symptoms arrive all at once: extreme fatigue, high fever, uncontrollable shivering alternating with profuse sweating, night sweats, headache, nausea, abdominal pain, loss of appetite, weight loss, muscle pain, cough, mental confusion, and extreme fatigue. Really extreme.

Babesiosis is not subtle. Symptoms, arriving 10-30 days after being host to a tick, are akin to those of Anaplasmosis, plus it destroys red blood cells and platelets. From the latest data published by the CDC, Massachusetts has more cases of Babesiosis than any other state.

The CDC uses the term "malaise," but this does not convey the soul-crushing lethargy of either of these full-speed infections. Not everyone exhibits all the symptoms, and many of these symptoms overlap with what people expect if they have the flu, causing many people to delay seeking a medical evaluation, or doing so, getting a misdiagnosis.

Actually, these days, diagnosis and treatment are straightforward. Do you have some or all of that litany of symptoms, especially fever and fatigue? Were you in any place a week or four ago where there might have been ticks? That's it. A blood sample will be taken, but especially early in the course of the infection the test results can be false negative (says you don't, but you do). Standard medical practice is to start antibiotic treatment immediately. Treatment should never be delayed until the lab results are back. These days, there is an assumption that more than one disease is transmitted from the same tick, so for Babesiosis, doctors may prescribe multiple antibiotics.

Neither casual contact nor intimate sexual contact will pass on any of these diseases, but receiving a blood transfusion has been a confirmed vector. There are no laboratory screening tests to verify that donated blood is not infected. 

Not treating infections in a timely fashion can have very serious consequences. Delayed treatment may require hospitalization and intravenous antibiotics. Especially in older or immuno-compromised people there are risks of compromised breathing, kidney failure, nerve damage and death. A practical point - your guests can contact a tick disease here, then travel to regions where doctors may not have tick disease awareness. Your parting words might include "Safe travels, and if you develop a rash or become ill, tell your doctor you were in tick territory."

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