Lyme disease

Lyme disease, or borreliosis, is an emerging infectious disease caused by at least three species of bacteria belonging to the genus Borrelia. Borrelia burgdorferi is the predominant cause of Lyme disease in the United States, whereas Borrelia afzelii and Borrelia garinii are implicated in most European cases.
Lyme disease is the most common tick-borne disease in the Northern Hemisphere. Borrelia is transmitted to humans by the bite of infected ticks belonging to certain species of the genus Ixodes (the hard-bodied 'hard ticks').[2] Early manifestations of infection may include fever, headache, fatigue, depression, and a characteristic skin rash called erythema migrans. Left untreated, late manifestations involving the joints, heart, and nervous system can occur. In most cases, the infection and its symptoms are eliminated with antibiotics, especially if diagnosis and treatment occur early in the course of illness. Late, delayed, or inadequate treatment can lead to late manifestations of Lyme disease which can be disabling and difficult to treat.

Antibiotics are the primary treatment for Lyme disease; the most appropriate antibiotic treatment depends upon the patient and the stage of the disease. The antibiotics of choice are doxycycline (in adults), amoxicillin (in children), and ceftriaxone. Alternative choices are cefuroxime and cefotaxime. Macrolide antibiotics have limited efficacy when used alone.
Results of a recent double blind, randomized, placebo-controlled multicenter clinical study, done in Finland, indicated that oral adjunct antibiotics were not justified in the treatment of patients with disseminated Lyme borreliosis who initially received intravenous antibiotics for three weeks. The researchers noted the clinical outcome of said patients should not be evaluated at the completion of intravenous antibiotic treatment but rather 6–12 months afterwards. In patients with chronic post-treatment symptoms, persistent positive levels of antibodies did not seem to provide any useful information for further care of the patient.

In later stages, the bacteria disseminate throughout the body and may cross the blood-brain barrier, making the infection more difficult to treat. Late diagnosed Lyme is treated with oral or IV antibiotics, frequently ceftriaxone for a minimum of four weeks. Minocycline is also indicated for neuroborreliosis for its ability to cross the blood-brain barrier