What is Leptospirosis?

Leptospirosis is a disease caused by bacteria belonging to the genus Leptospira. The spirochetes infect humans and many types of domestic and wild animals. Globally, it is considered to be the most widespread infection spread from animals to humans. The severe form of the disease afflicts one million people each year, particularly among communities in tropical areas of the world that have limited access to healthcare. Leptospirosis is considered a neglected infectious disease as it is less well known, yet causes greater health impacts, than other infections such as Dengue fever. Infections caused by leptospires are potentially fatal and cause injuries to various organs, including the kidneys, liver, eyes, and central nervous system. For more information, please visit the CDC’s leptospirosis website.

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The Leptospirosis Research Laboratory is directed by David Haake, M.D., a Staff Infectious Diseases Specialist at the VA Greater Los Angeles Healthcare System. He is also a Health Sciences Clinical Professor of Medicine & Microbiology, Immunology, and Molecular Genetics at UCLA.

What Do We Research?

The focus of our research is to find better ways to diagnose, treat, and prevent leptospirosis. We do this by studying leptospiral proteins involved in the mechanisms by which Leptospira interrogans causes infection and disease. Some of these proteins are located on the bacterial surface and in the outer membrane, where leptospires contact the mammalian host.

One particularly interesting class of outer membrane proteins that we helped to discover are the leptospiral immunoglobulin-like domain (Lig) proteins. The Lig proteins are required for infection and are known to facilitate interactions with a number of human proteins. For example, binding of the Lig proteins to complement regulators protects leptospires from host defense mechanisms. Our research elucidated one mechanism by which Lig proteins are upregulated during infection. In fact, the Lig proteins are some of the first proteins recognized by the antibody response during infection, which makes them particularly good serodiagnostic antigens. Immunization with the Lig proteins is particularly effective in preventing leptospirosis in preclinical models. More work is needed to translate these discoveries into vaccines that can be used in humans, pets, and farm animals.