Headlines
As reported by the New Haven Register, July 5, 2006.
Ticks Carry More Than Lyme Disease
By Ti Badri
The first study of its kind in Southern Connecticut has revealed that ticks may carry up to half a dozen disease-causing micro-organisms, which could explain why some people with Lyme disease continue to suffer mysterious symptoms for decades despite long-term treatment.
Researchers at the University of New Haven are also developing a new type of test to reveal these previously unrecognized organisms, which may complicate diagnosis and treatment of Lyme disease.
The new test is designed to avoid the protracted nightmare that Julie Hunter, 20, has suffered since she contracted Lyme disease in 1999.
Physicians quickly diagnosed the bacterium that causes Lyme disease, but missed a more elusive germ that the tick also injected into her bloodstream.
"Present test results are unreliable and doctors stop as soon as the test comes out negative," said Hunter’s father, David Hunter of Southbury.
He said that if the UNH test works, "It would greatly help the patient community. Julie had a co-infection that interfered with her Lyme disease treatment."
Many people with lingering symptoms of Lyme disease may actually be infected with one or more previously unrecognized bacteria, viruses, parasites and protozoa, said Eva Sapi, assistant professor of molecular biology at UNH and senior author of the study, which is being prepared for publication.
Doctors, infectious disease specialists and Lyme disease experts said the problems posed by stowaway pathogens are significant. However, some scientists said the new test could be impractical, expensive and prone to poor quality control.
Current Lyme disease tests depend on antibodies produced by the patient in response to the invading spirochete. The test being developed by UNH’s molecular biology department is intended to work by identifying specific fragments of foreign DNA generated by the infectious organisms.
The Lyme disease project will shed light on the types and frequencies of tick-borne microorganisms in southern Connecticut, Sapi said.
Researchers hope the new test kits will provide a quick and reliable method of diagnosing tick-borne diseases, enabling doctors to better treat patients suspected of having Lyme disease.
"Lyme patients will finally know what’s going on. They will finally have closure," Sapi said.
Experts see the potential benefits of the new test, but question its practicality. The test is based on polymerase chain reaction, a standard method of "amplying," or making countless copies of a piece of DNA.
"PCR is doable in ticks, but researchers have to keep track of emerging infections," said Stephen Wikel, professor of immunology at the University of Connecticut Health Center.
"The test is feasible using real-time PCR", said Connecticut’s chief entomologist, Kirby Stafford III. Real-time PCR can detect specific DNA sequences as they happen in the reaction chamber, allowing researchers to keep track of quantities of reacting materials at every stage of the process.
Other doctors aren’t so sure.
"Individual tests using PCR are quite expensive and depend on quality control", said Dr. John Shanley, infectious diseases specialist at the UConn Health Center.
Prior to the study carried out at UNH, there were no in-depth studies carried out in Southern Connecticut to determine what kind of microorganisms ticks have and what co-infections are present, Sapi said.
These tick-transported pathogens include Bartonella, Mycoplasma and the virus that causes Colorado tick fever. Bartonella causes cat scratch disease, and Mycoplasma is a bacteria-like organism associated with respiratory illness.
Researchers found that some ticks collected around Bridgeport and Hamden over the course of a year were infected with up to six different microorganisms.
"We always believed only one bacteria was present in the ticks, now we know that there are co-infections," Sapi said.
Multiple infections are very difficult to properly diagnose and treat, she said. Patients with multiple infections have significantly more complicated symptoms and poorer outcomes because different infections require different treatments, Sapi said.
For example, antibiotics cannot be used if a patient is found to have a viral co-infection; anti-viral drugs must be used instead. If left untreated, the corkscrew-shaped Lyme disease spirochete can cause fever, arthritis, swollen lymph nodes, aches and pains, and sometimes, a bull’s-eye rash. However, not all patients will have all the associated symptoms.
Whatever scientists can do to ameliorate the anguish of Lyme disease should be pursued, including new tests, said David Hunter.
"I think it would be huge for the patient community because many people remain largely ignorant of the impact of the disease," he said.