Where Is It?

Leptospira is worldwide in distribution but is most common in temperate or tropical climates. There are over 200 serotypes but L. interrogans is the most abundant.

It can be found wherever there is water (especially floodwaters) and animals. It is found in virtually all animals, and outbreaks often occur after flooding, when infected urine washes into common water.

About 160 mammalian species have been identified as natural carriers of pathogenic leptospires, including feral, semi-domestic, farm animals and pets. The bacterium infects animals’ kidneys and the infectious period of natural hosts can be lifelong.

Exposure

Outbreaks of leptospirosis are usually caused by exposure to water contaminated with the urine of infected animals and people become infected through contact with water, food, or soil contaminated with urine from these infected animals. This may happen by ingestion or through skin contact, especially with mucosal surfaces, such as the eyes or nose, or with broken skin.

It is not known to spread from person to person but is an occupational hazard for many people who work outdoors or with animals, for example, farmers, sewer workers, veterinarians, fish workers, dairy farmers, or military personnel.

It is a recreational hazard for campers or those who participate in outdoor sports in contaminated areas and has been associated with swimming, wading, and canoeing in contaminated lakes and rivers.

The lack of effective cross-reactive vaccines limits the potential effect of immunisation strategies in animals and humans. The true spread and increase of leptospirosis remains unknown as the quality and availability of diagnostic tests, testing facilities and surveillance systems are very variable and frequently not available.

Treatment

Leptospirosis can be treated with oral penicillin, amoxicillin, azithromycin or doxycycline if mild, or IV penicillin or ceftriaxone if more severe.