As many as 70 percent of deer ticks are capable of passing on conditions like Lyme disease and recurring fevers to the humans they bite, says a recent study conducted at the Columbia University Center for Infection and Immunity.
Published in the September issue of the peer-reviewed Vector-Borne and Zoonotic Diseases, the study describes deer ticks as carriers of a "plethora of pathogens" potentially dangerous to humans. The most common disease-producing bacterium found in the roughly 300 New York deer ticks examined was Borrelia burgdorferi-the infectious organism that causes Lyme disease.
Researchers additionally found some deer ticks (2%) to be carriers of the Powassan virus, which can lead to a severe central nervous infection, along with life-threatening brain swelling and inflammation caused by encephalitis.
Symptoms of Lyme disease can range from fever, chills and body aches to joint swelling, weakness, severe fatigue, trouble concentrating and temporary paralysis. Many-though not all-people infected will see a bull's-eye rash between three and 30 days after infection.
Although Lyme disease is most common in the Northeast, it's been found in all 50 states. Those who live, or spend time, in grassy or wooded areas are most at risk. According to the Centers for Disease Control (CDC), more than 20,000 cases of Lyme disease are reported each year. Yet because most doctors do not report new cases of Lyme disease to the CDC, the actual number of new Lyme disease cases each year has been estimated to be as high as 200,000, says Connecticut-based neurologist Harriet Kotsoris, M.D., medical director of Time for Lyme-a non-profit organization working to eliminate tick-borne diseases through research, education and both state and national legislation.
"Couple the study results with these statistics, and it's no wonder the CDC has classified Lyme disease as a health epidemic," Dr. Kotsoris continues, adding that since 1991 the number of those infected with Lyme disease has doubled.
Because deer ticks can carry multiple disease-producing bacteria and microorganisms, it's also possible for a human to develop two or more infections from one bite, researchers say. The Columbia study found that in addition to the bacteria that leads to Lyme disease, it is common for deer ticks (scientifically known as Ixodes scapularis ticks) also to carry:
· Babesia microti-a parasite that can infect red blood cells. Some people with the infection never experience any symptoms. In others, the flu-like symptoms can be life threatening.
· Anaplasma phagocytophilum-bacteria that can lead to an infectious disease called anaplasmosis. Treated with antibiotics, symptoms are flu-like and generally range from mild to moderate.
· Also found in a small percentage of ticks (2%) was Borrelia miyamotoi, a bacterium that is similar to the Borrelia lonestari, but has not yet been proven to cause disease in humans.
This study was made possible by a grant funded in part by Time for Lyme and the Columbia Lyme Center to support a fellowship to the lead investigator, microbiologist and Columbia postdoctoral research scientist Rafal Tokarz, Ph.D., an expert on tick-borne illnesses in humans.
"The results corroborate what many have feared-that more ticks are carrying more pathogens, and that without physician and public education, we could have a skyrocketing health crisis on our hands," Dr. Kotsoris adds.
Congress is currently considering legislation that would mandate the U.S. Department of Health and Human Services to create a Tick-Borne Diseases Advisory Committee to coordinate efforts and improve communication between the federal government, medical experts, physicians and the public.
About Time for Lyme
Time for Lyme is an organization dedicated to eliminating the devastating effects of Lyme disease and other tick-borne illness. Its mission is to prevent the spread of disease, develop definitive diagnostic tools and effective treatments, and to ultimately find a cure for tick-borne illness by supporting research, education, and the acquisition and dissemination of information. In addition, TFL continues to act as an advocate for Lyme disease sufferers and their families through support of legislative reform on the federal, state and local levels. www.timeforlyme.org.
