Objectives: Leptospirosis continues to be a significant zoonosis of the developing world. Globalization, in the context of international travel, particularly for recreational activities and military expeditions, has led to increased exposure of individuals from the developed world to the disease, as recent outbreaks show.
Methods: We evaluated the trends in annual leptospirosis incidence for individual countries worldwide through reports from national and international organizations, the published medical literature on the subject, and web searches with the terms 'leptospirosis' and the individual country names. Inter-country variations in leptospirosis incidence, when relevant official data were available, were also analyzed.
Results: The Caribbean and Latin America, the Indian subcontinent, Southeast Asia, Oceania, and to a lesser extent Eastern Europe, are the most significant foci of the disease, including areas that are popular travel destinations.
Conclusions: Leptospirosis is a re-emerging zoonosis of global importance and unique environmental and social correlations. Attempts at global co-ordination and recognition of the true burden of an infectious disease with significant mortality should be encouraged.