May is Lyme Disease Awareness Month
Lyme is the most prevalent vector-borne disease and one of the fastest spreading diseases throughout the United States, and the subjects of diagnosis and treatment of Lyme are politically-charged.
This series of diaries is designed to provide information to the Daily Kos community both for Lyme disease prevention and for those Kossacks living with Lyme. Because the disease is often missed by physicians, these diaries may assist an individual or two in pursuing testing which might otherwise have been missed.
The LymeDiseaseAwareness series will be eclectic including personal statements, informational pieces about the science of Lyme, and calls to action for community and political advocacy.
We hope you'll all join us in learning about this rampant disease and the medical/industrial/political morass in which Lyme patients find themselves.
The LymeDiseaseAwareness Team
Today's diary by: 42
Ticks: Cesspools of Disease
While parasitic ticks have been around for centuries, the diseases they spread have recently been undergoing intense scrutiny. These diseases are considered emerging diseases as they are now rapidly increasing in scope and range, with new tick-borne disease pathogens still being discovered.
With just one blood meal, ticks have the potential to transmit multiple diseases. Co-infections are the rule, not the exception. Bartonella is more prevalent than Lyme in some areas of New Jersey. Eighty-four percent of the ticks that Eva Sapi, PhD. studied in CT were infected with various mycoplasma.
Out of 820 species of ticks, only 100 or so can transmit illness to humans. Eighty-four of those species can be found in the United States. Several of those are of particular concern for the spread of disease, most notably, the members of the Ixodes genus for their role in spreading Lyme disease.
Westerners must contend with the western blacklegged tick (Ixodes pacificus), while in the East and Mid-West the blacklegged deer tick (Ixodes scapularis) is the most common vector of Lyme and other diseases. The common and much larger dog tick (Dermacentor variabilis) is found in the East and Central portions of the country, and while it is normally not known for Lyme, it can transmit other diseases, in particular, Rocky Mountain Spotted Fever.
The aggressive lone star tick(Amblyomma americana), found in southeastern and south-central United States, transmits a milder illness, Master’s Disease aka STARI, Southern Tick Associated Rash Illness. (This illness does NOT show up on the current Western Blot Lyme tests.) Especially for the eastern half of the country, there is much overlap of tick ranges with the lone star tick now being reported as far north as Maine.
Tick Life Cycle
The spread of Lyme disease is closely linked to the tick’s stage of development - primarily the immature form, the nymph, causes most human infection.
As members of the arachnid family, ticks are not insects, but are closely related to mites, spiders and scorpions. They have 2 body parts, not 3. Adults and nymphs have 8 legs; larva have 6;
The life cycle of the black-legged deer tick, like other ticks, encompass four stages: Egg -> larva -> nymph -> adult. Life cycles, however, differ in many areas based on local and regional habitat and climactic variation. Typically though, ticks feed once, then molt and move to the next stage of development. The entire process takes 2 – 3 years.
2 year life cycle
Eggs are laid from late fall to winter. Depending on the species, usually only 1 batch of 200 – 23,000 eggs are laid. The Larva or "seed tick" emerges from late July to September with peak activity being in August. These ticks are ‘pepper-sized’. [To get an idea of hard they are to spot, try sprinkling a little ground pepper on your arm, and see if you can find them.] It is rare, but not impossible for the larva to be already infected with pathogens. Since they are small, they do not travel far from where they are hatched; and prefer shady, moist areas - especially leaf litter, where they await their first blood meal from mice, birds, moles, chipmunks, or squirrels. These small animals are natural reservoirs for disease pathogens, which are then transmitted to the larva when they feed. The larva triple in size, and molt after at least one feeding.
It is during the nymph and adult stages that ticks go on to infect other small mammal species, as well as migrating birds, deer, domestic animals and humans.
Nymph
The poppy seed size nymphs emerge in Spring with the return of warm weather. Their peak activity is May and June. Like the larva they prefer shadier, moist "understory" and leaf litter, the underside of shrub leaves, fallen tree limbs and logs, stone walls, and the undersides of picnic tables. Nymphal ticks are more mobile than the larva; they can and do climb to go after their targeted meal, including humans. After feeding for 3-4 days, the nymph drops off, and starts the molting process.
The adult ticks emerge in the fall – with a peak in October. They are roughly sesame seed size with the female being larger. The smaller male ‘usually’ feeds just on moisture. They are active above ground level, questing about waist-high from tall grass or weeds where it is easier for them to attach to their larger prey.
4 stages - deer tick
Deer ticks preferred host is, naturally, deer. However, if there are no deer in the area, they then will attach and feed on any larger animal that happens to come by: bear, coyote, fox, woodchucks, raccoons, dogs, even humans. These larger creatures carry the ticks into new habitats where the disease cycle starts over again. Male ticks usually mate with one or more females and then die, although some may live for several months. Females die soon after depositing their eggs in protected habitats on the ground.
Tick-born Pathogens:
• Borrelia burgdorferi (Bb) and other Borrelia species, such a B. garinii, B. afzelii...
With over 300 known strains of the Lyme disease bacteria worldwide, Lyme disease is the fastest growing infectious illness in the United States, growing at five times the rates of the AIDS and HIV infections. Lyme disease has been reported in every State, every continent and nearly every area including Canada and the Caribbean.
Lyme disease is a multi-system disease, which left untreated can affect virtually every tissue and every organ of the human body. Symptoms of Lyme disease can range widely and include migraines, paralysis, joint pain, cardiac trouble, and overall malaise. It can be fatal.
According to conservative CDC estimates, as many as 344,860 people may have acquired the disease as of 4/25/09 - more than cases of AIDS, West Nile Virus, and Avian Flu combined. The CDC states that only 10% of cases are reported.
• Babesia microti, B. duncani/WA1, MO1, B. divergens
Babesia are protozoa that reside in the tick salivary glands - transmission is much quicker than that for Borrelia burgdorferi.
Babesiosis is an infection caused by a parasite that infects red blood cells. Babesia microti is believed to be the most common piroplasm infecting humans, but scientists have identified more than 20 piroplasms carried by ticks. Ticks may carry only Babesia or they may be infected with Babesia and Lyme spirochetes. The first case of babesiosis was reported in Massachusetts 40 years ago, but cases have been reported all across the U.S., Europe and Asia since then.
Symptoms of babesiosis are similar to those of Lyme disease, but it more often starts with a high fever and chills. As the infection progresses, patients may develop fatigue, headache, drenching sweats, muscle aches, nausea and vomiting. Babesiosis is often so mild it is not noticed but can be life-threatening to people with no spleen, the elderly and people with weak immune systems. Complications include very low blood pressure, liver problems, severe anemia (a breakdown of red blood cells), and kidney failure.
Time for Lyme
• Ehrlichia chaffeensis or Human Monocytic Ehrlichia (HME)/Anaplasma phagocytophilum or Human Granulocytic Anaplasmosis (HGA)
Transmission time for HME/HGA is much less than the 24 hours that is generally ascribed to Lyme.
Ehrlichiosis is common in two forms, both of which are caused by tick-borne parasites called Ehrlichia that infect different kinds of white blood cells. In HME (human monocytic ehrlichiosis), they infect monocytes. In HGE (human granulocytic ehrlichiosis, also called anaplasmosis), they infect granulocytes. Ehrlichiosis and anaplasmosis share the same symptoms: sudden high fever, fatigue, muscle aches and headache. The disease can be mild or life- threatening. Severely ill patients can have low white blood cell count, low platelet count, anemia, elevated liver enzymes, kidney failure and respiratory insufficiency.
Effective diagnosis is difficult, as only two species of these parasites have been identified and scientists believe there may be dozens of other species causing Erlichiosis. Ehrlichia parasites multiply inside host
cells, forming large mulberry-shaped clusters called morulae which doctors can sometimes see on blood smears, but most often a diagnosis is surmised when patients do not respond well to treatment for Lyme
disease.
• Bartonella henselae (cat scratch fever) and other Bartonella-like organisms
Bartonellosis is known to be caused by a bacteria carried by fleas, body lice and ticks. Scientists suspect that ticks are a source of infection in some human cases of bartonellosis. People with tick bites and no known exposure to cats have acquired the disease. People who recall being bitten by ticks have been co-infected with Lyme and Bartonella. More research needs to be done to establish the role of ticks in spreading the disease. Bartonellosis is often mild but in serious cases it can affect the whole body. Early signs are fever, fatigue, headache, poor appetite and an unusual, streaked rash. Swollen glands are typical, especially around the head, neck and arms. Lymph nodes may be enlarged and the throat can be sore. Polymerase chain reaction (PCR) and tissue biopsy can be used to confirm a diagnosis; however they are insensitive, as are standard blood tests.
• Mycoplasmas, including M.fermentans of Gulf War Syndrome infamy
• Rickettsia rickettsia or Rocky Mountain Spotted Fever (RMSF)
• Francisella tularensis (Tularemia)
• Q Fever
• Colorado Tick Fever
• Tick Relapsing Fever
• Tick Paralysis - while not an infectious agent, this disease is caused by a neurotoxin produced by an engorged, egg-laying female tick. The paralysis starts in the lower body and spreads to the rest of the body. This can cause respiratory failure and death. Death in young children can occur in one or two days. If the tick is found and removed, the paralysis generally resolves.
• Viruses, nematodes and other unknown agents may also be transmitted.
For every known tick-transmitted disease, it is theorized that there is another awaiting discovery. These co-infections may add to the severity of Lyme disease and make treatment more difficult. There is still much unknown about tick-borne diseases and much more research waiting to be done.
Next week, we will discuss how you can protect yourself, your pets and your property.
