Search

Polymerase chain reaction (PCR) testing can detect Borrelia (B.) burgdorferi DNA in joint fluid samples taken from patients with Lyme arthritis. Lyme arthritis is an inflammatory disease, caused by tick-borne bacteria, that affects the large joints and may be followed by neurologic and cardiac complications. Researchers in two different laboratories used four genetic tests to evaluate the joint fluid of 88 Lyme arthritis patients and 64 healthy subjects. B. burgdorferi DNA was detected in 85% of the arthritis patients and none of the comparison subjects. Of 73 arthritis patients who had not been treated or had been treated with oral antibiotics for less than one month, 70 had positive test results. Only seven of 19 patients who had received intravenous antibiotics or oral antibiotics for more than one month had positive test results. Three of the tests detected DNA in 75% to 89% of positive patients. Test four detected DNA in only 56% of positive patients.

Giving antibiotics to individuals who have been bitten by a deer tick may not be necessary, even in areas with a high prevalence of Lyme disease. Deer ticks carry the bacterium Borrelia (B.) burgdorferi, which causes Lyme disease. Proper care and possible treatment for deer-tick bites in areas where Lyme disease is prevalent. In a one-year study of 387 people who had been bitten by deer ticks, 205 were given the antibiotic amoxicillin and 182 were given a placebo, or inactive substance. Some brought the ticks with them, and of 344 ticks analyzed, 15% were infected with B. burgdorferi. Only two patients on taking placebo developed symptoms of B. burgdorferi infection, and none of those on amoxicillin developed the infection. The risk of infection did not differ significantly between the group taking amoxicillin and the group taking placebo.