Immune system = Set of mechanisms (antibodies, white blood cells…) protecting us from infections.

Intermediate host = Host of a parasite within which the parasite goes from a developmental stage to another.

Intracellular = Defines a bacterium that needs to be inside a cell to survive and multiply. Some bacteria are strictly intracellular, since they cannot multiply outside of a cell. Then there are facultative intracellular bacteria that can replicate even without a host cell. The strictly intracellular bacteria are difficult to grow in the laboratory and thus often remain undetected with cultivation methods routinely used for diagnostic purposes.

Leishmania = Chronic parasitic disease that presents in three forms depending on the Leishmania genre: cutaneous (skin), visceral, and mucosal. The first one is usually benign, whereas the two others can be very serious. These parasites are transmitted to humans and animals (especially dogs) by the sand fly.

Leptospirosis = Infectious disease affecting both humans and other mammals (dogs, pigs, horses) with varing symptoms. It is caused by a bacterium that survives in stagnant water, mud, and humid soil. Humans often have flu-like symptoms such as fever, shivers, and headaches. The more severe form infects the kidneys and the liver, causing a jaundice, and a 20% mortality.

Meningitis = Inflammation of the meninges, which are the membranes surrounding the brain and spinal cord.

 Meningoencephalitis = Simultaneous inflammation of the brain and meninges, which are the membranes around the brain and spinal cord.

Mite = Arthropod part of the arachnid group (spiders). Mites have 4 pairs of legs whereas insects only have 3. There is a big number of mites but most of them cannot be seen with the naked eye. However, some of them, like the tick, can reach a size of a few millimeters.

Mycobacteria = Bacterial family present in the environment (soil, water, food, plants) with a thick outer layer that makes them resistant to many anti-bacterial treatments. Tuberculosis and leprosy are caused by members of this family.