February 08, 2013

Rachel Hansohn ‘13Hamline University Biology Senior SeminarAbstract:

Prophylactic Topical Antibiotic Treatment of Lyme Disease

Lyme disease is caused by Borrelia burgdorferi, a bacteria that is spread through the bite of an infected tick. When left untreated, it causes flu-like symptoms, skin lesions, neurological complications and arthritis as the bacteria spreads throughout the body over a period of months. The current treatment for this systemic bacterial infection is oral doxycycline or amoxicillin administered over a period of 10-20 days. A major problem with treating Lyme disease is that it is hard to diagnose accurately and if the bacteria has spread throughout the entire body the antibiotics are not as effective. There are also side effects that accompany systemic antibiotics and there are certain people who cannot take them such as those who are allergic to the antibiotics, women who are pregnant and young children. To overcome these problems, researchers tested the efficacy of topical azithromycin as a prophylactic treatment using a mouse model. They infected the mice with the bacteria by two methods; either injection or by attaching ticks that were known to be infected. The mice that were infected via injection were treated with topical 5 percent azithromycin at varying intervals. The mice that were infected by tick bite were treated immediately after removal of the ticks with different azithromycin concentrations. After treatment, bacteria were not found in any mice that were inoculated via either needle or tick. This indicates that the use of topical azithromycin formulations is a promising way to prevent Lyme disease when applied shortly after a tick bite.