The following year, scientists found spirochetes in blood samples and other tissues from people with Lyme disease. These spirochetes had the same features as the ones isolated previously from the Ixodes ticks. They went on to develop diagnostic tests and conduct further animal studies to define the most effective therapies. The ticks that transmit this disease are very small, the size of sesame seeds as adults, and in approximately 30 percent of the confirmed cases, no tick bites can be documented. Symptoms include a bull's-eye rash in about 70 percent of human patients, malaise, fatigue, joint pains, neurological signs, cardiac abnormalities, and arthritis.
Patients develop antibody titers to the disease, but a single test is difficult to interpret.
Nearly all Lyme disease patients can be effectively treated with an appropriate course of antibiotic therapy. In general, the sooner such therapy is begun following infection, the quicker and more complete the recovery. Antibiotics, such as doxycycline, cefuroxime axetil, or amoxicillin taken orally for a few weeks, can speed the healing of the erythema migrans rash and usually prevent subsequent symptoms such as arthritis or neurological problems. Doxycycline will also effectively treat most other tick-borne diseases. Patients younger than 9 years or pregnant or lactating women with Lyme disease are treated with amoxicillin, cefuroxime axetil, or penicillin because doxycycline can stain the permanent teeth developing in young children or unborn babies.