Sciensano is home to the National Reference Laboratory for animal leptospirosis in Belgium and also has expertise in the molecular diagnosis of acute human cases within 10 days of the onset of symptoms. Sciensano is also responsible for the epidemiological surveillance of the disease in humans in Belgium.
Leptospirosis is an infectious human and animal disease caused by bacteria of the genus Leptospira. Humans are contaminated via the skin or mucous membranes (mouth, nose, eyes) through contact with water or contaminated soil, or through direct contact with an infected animal. It is a zoonosis that is widespread throughout the world, and more particularly in tropical areas.
The disease represents a major public health problem in hot and humid areas, particularly in Latin America and Southeast Asia. In Belgium, the risk of human contamination remains limited.
What is leptospirosis?
Leptospirosis is a zoonosis (transmitted from animals to humans), caused by bacteria of the genus Leptospira, which have a particular spiral shape. The main natural reservoirs for the bacterium are small rodents (rats, mice), livestock (cattle, goats, horses, pigs) and pets (dogs, cats). All these animals excrete leptospires in their urine. The bacteria can survive for a few weeks in a hot and humid environment (stagnant water, muddy ground).
Humans or animals become contaminated via the skin or mucous membranes (mouth, nose, eyes) through contact with water or contaminated soil, or through direct contact with an infected animal.
The people most at risk of infection are certain professional groups (breeders, veterinarians, garbage collectors, farmers, etc.), as well as people engaging in water sports in fresh water (fishing, kayaking, swimming, etc.).
In humans, leptospirosis can present with a wide range of clinical manifestations, ranging from mild flu-like illness to multiple organs potentially being affected. In the severe form (Weil’s syndrome), high fever, jaundice, impaired consciousness, hemolytic anemia and hemorrhagic manifestations are usually observed.
In animals, an infection is generally asymptomatic in rodents and insectivores. In farm and domestic animals, brief bacteremia is followed by colonization of the kidneys and liver, where leptospires can lead to acute or chronic infections, manifesting as kidney and liver failure, loss of appetite, pulmonary hemorrhagic syndrome, infertility, jaundice, abortion as well as ocular complications such as uveitis.