Understanding Lyme Disease
Evolution of Lyme Disease
Though Lyme Disease was first observed in Connecticut in 1975, it took several years to realize that it was a tick-borne ailment, and a total of six years to identify the bacterial organism (Borrelia burgdorferi) responsible for the sickness. Further research revealed that the invertebrate responsible for transmitting the disease to humans is the deer tick (Ixodes scapularis).
Contrary to popular belief, this tiny blood-sucking animal is not an insect. Rather, it belongs to the Arachnid classification, which also includes mites and spiders. Since 1975, the frequency of Lyme Disease has been steadily increasing. Many health experts now consider the malady to have reached epidemic status.
The Bull's Eye Rash
Since the first diagnosis in the 70s, Lyme Disease has continued to spread sometimes at an alarming rate. Following are a few basic facts that can help define the nature of Lyme Disease and some biological information about the wild animals that are involved in the transmission of the sickness.
- It is estimated that only 50 percent of bites by infected ticks leave the telltale Bull's Eye Rash associated with Lyme Disease.
- Pennsylvania, New York, New Jersey, Wisconsin, Connecticut, Massachusetts, Minnesota, Maryland, New Hampshire and Virginia are the ten states that have the most cases of Lyme Disease.
- The bacteria that causes Lyme disease is hard to detect and hard to kill.
- Deer do not cause Lyme Disease.
- Common Symptoms for Lyme Disease include: fatigue, neck stiffness or pain, jaw discomfort, muscle pain, joint aches, swollen glands, memory loss, cognitive confusion, vision problems, digestive issues, headaches and fainting.
Lyme Disease Epidemic
Is Lyme Disease Becoming An Epidemic
Current Status of Lyme Disease
Here is how the Center for Disease Control (CDC) defines an epidemic: "An epidemic is the occurrence of more cases of disease than would normally be expected in a specific place or group of people over a given period of time."
Writers of all stripes are sounding off on the increasing number of cases of Lyme Disease, not only in the United States, but in other parts of the world as well. At Creations Magazine the headline read, Is Lyme Disease the New HIV?, while at Mindful Healthy Life, another article was titled, Lyme Disease: An Epidemic. Even Mitt Romney, the Republican presidential nominee of 2012, joined the fray when he released a flyer promising to address the problem of the Lyme Disease epidemic in Virginia.
Last July, Michael Specter wrote a piece for the New Yorker, called the Lyme Wars, in which he says that Lyme Disease is the "most commonly reported tick-borne illness in the United States". Specter goes on to discuss the various attitudes towards Lyme Disease by health professionals. And finally, as recently as August 2013, the CDC called this sickness a national epidemic after determining that only 10 percent of Lyme cases are actually reported.
A Corkscrew Bacteria
The Spirochete Bacteria
The spirochete group of bacteria are so named because of the corkscrew shape of each strand of bacteria. Of this group, the two most familiar species are the ones that are responsible for Lyme Disease and syphilis. Spirochete bacteria are usually found in viscous environments, such as the bloodstream and intestines of warm-blooded animals. However, not all these microscopic organisms are destructive, for some live in the intestinal tracts of large animals, primarily as an aid in digestion.
Lyme Disease Risk Map
The Importance of the Mouse
The bacteria that causes Lyme Disease in the human population begins its life cycle in the blood and tissue of the white-footed mouse. Since this mouse can also serve as a home for the deer tick larva, understanding the life habits of this small rodent is very important. For it is here that the tick picks up the disease-causing bacteria that it eventually transports to larger mammals, such as man.
The white-footed mouse can be found in grassy and brushy fields, as well as well-drained upland forests across the eastern two thirds of the U.S. This animal tends to nest underground, where they may have 2 to 4 litters a year with each birth containing 3 to 5 baby mice.
Please note: More recent research shows that other small mammals may also host both the Borrelia bacteria as well as the deer or black-legged tick.
Sizes of the Deer Tick
Stages of the Deer Tick Life Cycle
- in the spring pregnant female deer ticks drop from their host and lay their eggs under the leaf litter of the forest.
- In the summer the eggs hatch and turn into larvae. The larvae then find a host, such as small mammal or bird, where they attach themselves and feast on their blood.
- In the fall, the larvae fall to the grown and morph into a nymph. The nymph then goes into a dormant stage for the winter.
- In the spring the nymph finds another host, which may include small or large mammals, including man. At this the nymph can climb into low vegetation that grows near the ground. After feeding the nymph drops to the ground and turns into an adult.
- Throughout the fall both male and female ticks look for a larger host. At this stage the tick can climb several feet onto green vegetation and find a host in that manner.
- Adult males and females spend the winter on their host and then mate in the spring. The adults soon die after mating
The Deer Tick
It is important to note that the deer tick has a two year life cycle. During each winter the tick goes into a dormant stage only to be revived with warmer weather. In the United States there are two species of ticks than can carry the Lyme Disease bacteria. One is the deer tick (Ixodes scapularis), which is also called the black-legged tick. The other is simply called the western black-legged tick (Ixodes pacificus).
Though the adult tick is larger and readily able to find its way onto a large host, such as deer or man, it is the nymphal stage that more often transmits Lyme disease to the human population. Transmission by adult ticks occurs less frequently because the adults are easily visible and as a result they are usually removed before the bacterial organism can find its way into the bloodstream of the new host. On the other hand the nymph, because it is so small, can easily go undetected in its new home.
Understanding this part of the science enables us to be on the lookout for nymphal infections in the late spring, when they are most active. Furthermore, since the nymph can only access low-growing vegetation, everyone must take preventive action, when walking outdoors in areas prone to Lyme Disease.
The Biology and Ecology of Lyme Disease
Effects of the Disease
So far, not much has been said about the diagnosis or treatment of Lyme Disease. Although this video is mainly about the biology and ecology of this ever-so-common sickness, the visual depiction does go a little bit further in discussing the effects of this disease.
Adult Deer Tick
Some Helpful Links To Keep Up With The Changing Situation
The information on the severity and widespread nature of this disease is changing all the time. For example, not only mice, but also chipmunks and shrews, may harbor the Borellia bacteria that causes the sickness.
Then there is the microbiological research, which shows that there are several species of Borellia bacteria, causing Lyme disease, not just one. To keep abreast of the latest developments, you might want to actively follow one of these sites, dedicated to providing current information about the disease.
Deer Do Not Cause Lyme Disease
Contrary to popular belief, deer are not essential to the spread of Lyme Disease, even though they often act as hosts for the mature deer tick.
John Griffin, the head of the DNR in Maryland, said that "even a dramatic reduction in the deer population would do little to dampen the disease." Further information is provided by the Animal Advocates of Howard County (MD), who stated that "killing deer increases the amount of food and cover available for mice, birds and other hosts, which in turn will boost tick numbers and escalates the spread of Lyme disease."
A Country & Western Celebrity Struggles With Lyme Disease
“All of a sudden he was back. There are still bad days, but some days he’s perfectly normal and it’s easy to forget that he is even battling anything.”
- Lisa Kristofferson, commenting on her husband's case of Lyme Disease
Several years ago, noted Nashville singer Kris Kristofferson was diagnosed with a disabling dementia that may have been related to Alzheimer's Disease. His symptoms included a debilitating memory loss, which his doctors suggested may have been caused by his participation in football, rugby and boxing during his younger years. After battling with the condition for a long time, one doctor suggested that Kris take a test for Lyme Disease. He did and the results were positive.
After receiving the diagnosis he underwent a three-week treatment for Lyme disease and surprisingly, the old, cantankerous Kris Kristofferson has returned. According to his wife, Lisa, he still has his bad days, but his overall memory and outlook on life have significantly improved. Gone are the anti-depressants and specialized Alzheimer meds and returning is a new Kris Kristofferson, who is able once again to go on the road and do live concerts for his fans.
Update: Lyme Diseases and Climate Change
Is a warming climate increasing the incidence of Lyme disease? Dr. John Aucott of the Johns Hopkins Rheumatology Lyme Disease Research Center in Baltimore thinks there is a connection. He believes that a series of warmer winters and springs can increase the activity of mice and deer ticks, the two main carriers of the bacteria, which causes the debilitating disease. Throw in increased outdoor activity by the human population during these times of warmer weather and perhaps, here lies at least part of the explanation why Lyme disease is increasing in the US.
Even with warmer winters, Dr. Aucott reminds us that the prime season for infection takes place during the months of June and July, when the nymph stage of the deer tick is most active. Furthermore, most cases of Lyme disease are concentrated in fourteen states located in the northeast and upper midwest sections of our country.
Questions & Answers
Can a tick bite cause a black and blue bruise?
First of all, let me clarify my role in this article. I am not a medical practitioner, just a science reporter. Keeping that in mind, I did a little research into the question and found some evidence that bites from ticks infected with Lyme disease could leave a bite that turns the same color as a black and blue bruise. Here's a good link from a reputable source with pictures: https://www.cdc.gov/lyme/signs_symptoms/rashes.htm...Helpful 5