Leptospires (pathogenic species) are elongated bacteria that are shaped like corkscrews or hooks. The disease known as leptospirosis causes flu-like symptoms in humans, but can also be severe and even fatal.

Worldwide, mainly in moist environments such as mud, freshwater lakes, rice fields, etc. These bacteria remain capable of multiplying for weeks in bodies of water.

Natural reservoir are mainly rats, mice, field hamsters, cattle, pigs and dogs.

Humans can become infected with leptospires through minor skin lesions and mucosal contact when they come into contact with urine from infected animals or water contaminated with urine from infected animals.

Mostly five to 14 days or up to 30 days

The disease, known as leptospirosis, begins with flu-like symptoms such as fever and muscle pain. Without treatment, the fever subsides after three to eight days, but then rises again. During this phase, headaches, meningitis, muscle pain and conjunctival haemorrhages can occur. In severe cases, the liver and kidneys can be damaged. The disease can last for more than three weeks; in severe cases, the mortality rate is up to ten per cent.

The disease is treated with antibiotics

There is an approved vaccine for some animals, but not for humans

Leptospirosis is a notifiable disease. On average, 10 to 30 people fall ill each year.

Leptospires are gram-negative, elongated bacteria from the spirochete order that can cause an infectious disease called leptospirosis. Leptospirosis is a zoonosis. This means that it can be transmitted from numerous wild, farm and domestic animal species to humans. Transmission usually occurs directly via the urine of infected animals or indirectly through contact with contaminated environments (e.g. water, soil). Leptospires enter the body via small skin lesions and mucous membranes. After entry, the leptospires primarily colonise the kidneys of their hosts and are excreted from there in the urine. Of the wild reservoir hosts, rodents - such as rats and mice - are the most important. In Vienna, around a quarter of all rats are carriers of the pathogen.

Warm and humid climatic conditions favour the survival probability and duration of leptospires in the environment. Due to climate change, heavy rainfall and flooding events are becoming more frequent. Coupled with the expected increase in temperature, this can lead to rising infection rates in humans and animals.

Certain occupational groups such as sewer workers, farmers, harvest workers and people who have close contact with animals or animal products (vets, abattoir workers, hunters) are particularly at risk of contracting leptospirosis. In addition, some cases of the disease are known to have occurred after sporting events in connection with exposure to water and mud (e.g. triathlons). In humans, the clinical picture ranges from flu-like symptoms to inflammation of the liver and kidneys and in rare cases can also lead to death. In cattle, pigs and small ruminants, leptospirosis can lead to subclinical disease progression through to serious reproductive disorders such as abortions, stillbirths, the birth of weak offspring and a decline in milk production.

Despite the relevance of the pathogen for human and animal health and the economic impact, we assume that leptospirosis is currently one of the underdiagnosed diseases. The reason for this is the often unspecific nature of the symptoms, which can be caused by a number of other pathogens or go completely unnoticed.