The bacteria that causes Lyme disease has been around for a super-whopping long time, according to evidence pried from ticks trapped in amber some 15 to 20 million years ago.
Researchers from Oregon State University (OSU) studied four ticks found in the Dominican Republic, and the sap-trapped critters revealed a large grouping of cells that bear a close resemblance to Borrelia, a type of bacteria that to this day causes Lyme disease.
The ticks represent the oldest known fossil evidence of Borrelia, and they suggest the startling notion that tick-borne bacteria has likely been delivering Lyme disease to humans for as long as there have been humans.
Soft-bodied bacteria aren't often preserved in the fossil record, but amber, which starts out as tree sap, makes a great preservation medium, as it slowly bides its time and becomes a mineral.
Lyme disease itself was not even identified until 1975. The disease -- which hampers the joints, heart and central nervous system -- can be cured with antibiotics if it's caught early, but it's often misdiagnosed.
The tick-borne disease has been on the rise, thanks to growing deer populations in many areas. Lyme disease cases in Nova Scotia, for example, nearly tripled in 2013 from the prior year.
"In the United States, Europe and Asia, ticks are a more important insect vector of disease than mosquitoes," noted George Poinar, Jr., professor emeritus in the Department of Integrative Biology of the OSU College of Science, in a press release.
"(Ticks) 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," Poinar said. "It's likely that many ailments in human history for which doctors had no explanation have been caused by tick-borne disease."
The oldest known case of Lyme disease was found in a 5,300-year-old Tyrolean "iceman" mummy from the Italian Alps.
"Before he was frozen in the glacier, the iceman was probably already in misery from Lyme disease," Poinar said.
The OSU findings were published in the journal Historical Biology.