Article: Lyme Disease

Description

Lyme disease results from infection with spirochetes belonging to the Borrelia burgdorferi sensu lato complex. In Europe and Asia, most cases of Lyme disease are caused by B. burgdorferi sensu stricto, B. afzelii, or B. garinii; however, in the United States, all cases are caused by B. burgdorferi sensu stricto. The spirochetes are transmitted to humans through the bite of infected ticks of the Ixodes ricinus complex.

Occurrence

Lyme disease occurs in temperate forested regions of Europe and Asia and in the northeastern, north central, and Pacific coastal regions of North America. It is not transmitted in the tropics.

Risk for Travelers

Travelers to endemic areas who have frequent or prolonged exposure to tick habitats could be at increased risk for Lyme disease.

Clinical Presentation

Manifestations of Lyme disease include a characteristic expanding rash called erythema chronicum migrans at the site of tick attachment, fever, arthritis, and neurologic manifestations, including facial palsy.

Prevention

Vaccine

A safe and efficacious vaccine was, until recently, available for protection from Lyme disease in endemic areas of the United States. However, the vaccine was withdrawn from the market by the manufacturer in February 2002 because of low sales and is no longer commercially available.

Other

Travelers to endemic areas should be advised to avoid tick habitats if possible. If exposure to tick habitats cannot be avoided, the application of repellents to skin and acaricides to clothing, as well as regular daily checks for any attached ticks, can reduce the risk of infection. Because transmission of B. burgdorferi is unlikely to occur in the first 36 hours of tick attachment, prompt removal of any attached ticks will help prevent infection.

Treatment

Travelers who have erythema chronicum migrans or other manifestations of Lyme disease should be advised to seek early medical attention. Lyme disease can usually be cured by an appropriate course of antibiotic treatment.

— Edward Hayes