Leptospirosis is a fever disease of worldwide distribution in both humans and animals. Its incidence is considerably underreported since many cases either remain asymptomatic or only have mild clinical symptoms and are diagnosed improperly or with a delay or are even misdiagnosed.
As many as 90 % of symptomatic patients have anicteric disease, non-specific fever with influenza-like symptoms or signs of serous meningitis. The remaining about 10 % develop more serious icteric disease (Weil’s disease) with liver and renal dysfunction.
In the Czech Republic, the disease occurs sporadically and has a long-term downward trend. In 1990–2008, 789 cases of leptospirosis were reported with the annual mean rate of 0.4 cases /100,000 population.
The epidemic potential of the disease was documented after floods in 2002 that afflected a part of the country. The annual mean incidence rates in 1990–2008 were 3.1 times as high in women as in men.