May 29, 2014
Lyme Disease May Have Been Around Long Before Humans: Study
Alan McStravick for www.redorbit.com - Your Universe online
If you are a camper or one who enjoys being in the outdoors, you are most likely well aware of Lyme disease and the precautions necessary to avoid being exposed to it. As the Centers for Disease Control and Prevention (CDC) notes, Lyme disease is caused by the bacterium Borrelia burgdorferi. Humans are made susceptible when they are bitten by infected blacklegged ticks. With simple actions like applying insect repellent, promptly removing attached ticks and avoiding tick-friendly habitats, infection can be prevented.
Those unfortunate enough to be exposed to Lyme disease will likely suffer from fever and fatigue as well as a persistent headache and a rash that arises around the affected area. Without prompt and proper medical attention, Lyme disease infection spreads to the joints, heart and nervous system and can potentially be fatal.
Lyme disease only made it onto the scene some 40 years ago -- or so we thought. New research out of Oregon State University is challenging that common knowledge. Thanks to new discoveries of ticks trapped in amber, the researchers have found that B. burgdorferi has called Earth home for some 15 million years, far pre-dating human existence on the planet.
The amber obtained for the study was sourced from the Dominican Republic. In it, they found the spirochete-like bacteria that is B. burgdorferi. Those results have been published in the journal Historical Biology.
Another related study by a team of OSU scientists found the first fossil record of Rickettsial-like cells. This is a bacteria that is responsible for causing many and various types of spotted fever. Samples for this study were located in Myanmar and contained ticks dating back some 100 million years. These results were published in Cretaceous Research.
“Ticks and the bacteria they carry are very opportunistic,” said George Poinar, Jr, a professor emeritus in the Department of Integrative Biology of the OSU College of Science, and one of the world’s leading experts on plant and animal life forms found preserved in amber. “They are very efficient at maintaining populations of microbes in their tissues, and can infect mammals, birds, reptiles and other animals.
“In the United States, Europe and Asia, ticks are a more important insect vector of disease than mosquitos,” Poinar said. “They can carry bacteria that cause a wide range of diseases, affect many different animal species, and often are not even understood or recognized by doctors."
“It’s likely that many ailments in human history for which doctors had no explanation have been caused by tick-borne disease,” he added.
With its discovery in 1975, Lyme disease could be illustrative of Poinar's point. Many people may likely have suffered from joint, heart and nervous system issues without realizing they had, in fact, been bitten by a tick. Now, we know that a quick course of antibiotics can cure the condition. With a surge in deer populations, there has been a significant increase in Lyme disease diagnoses.
This research is most interesting because it is verification of a specific bacterium, a soft-bodied organism that rarely shows up in the fossil record. Amber, which originates as a free-flowing sap, is the one exception that can capture and keep bacteria for posterity.
In addition to this latest find, Poinar has been responsible for revealing the ancient presence of diseases like malaria, leishmania and others over his 30-year career. His expertise in the field led Poinar to note that humans have likely been subjected to diseases, like Lyme disease, over the entirety of human history thanks to ticks. He cites the Tyrolean iceman, the oldest documented case of the disease, a 5,300-year-old mummified corpse found in a glacier in the Italian Alps.
“Before he was frozen in the glacier, the iceman was probably already in misery from Lyme disease,” Poinar said. “He had a lot of health problems and was really a mess.”