The global distribution of Lyme disease

Area of Science:

• Epidemiology
• Infectious Diseases
• Dermatology

Background:

• Erythema chronicum migrans (ECM) is the characteristic skin lesion of Lyme disease.
• First described in Sweden in 1909, ECM cases have been reported in at least 19 countries.
• Lyme disease was fully described in the United States in 1977, with endemic areas identified.

Purpose of the Study:

• To review the global distribution and vector associations of Erythema chronicum migrans (ECM).
• To highlight the expanding geographical range and potential for new vector identification in Lyme disease.
• To underscore the importance of recognizing ECM in diverse geographical locations.

Main Methods:

• Review of historical case reports and epidemiological data on ECM.
• Analysis of recognized tick vectors (Ixodes ricinus, Ixodes dammini, Ixodes pacificus) and their geographical ranges.
• Inclusion of reports on atypical vector associations (mosquitoes, Ambylomma americanum) and international cases (Australia).

Main Results:

• ECM has been reported across Europe, North America, and Australia.
• Established vectors in Europe and the US include Ixodes ricinus, Ixodes dammini, and Ixodes pacificus.
• Cases have been linked to other vectors like mosquitoes and Ambylomma americanum ticks, and international cases suggest broader distribution.

Conclusions:

• The global distribution of ECM and its association with multiple vectors indicate that Lyme disease may be more widespread than currently recognized.
• Further research is needed to identify all potential vectors and geographical areas where Lyme disease is endemic.
• Increased awareness and diagnostic capabilities are crucial for identifying ECM in diverse international settings.