Two millimeters in size, with fine wings, beige bodies and black beady eyes – sandflies don’t look like they could spread fear and terror. But they can be mean, especially in the tropics and subtropics, but also in the Mediterranean region. Because there, the little bloodsuckers can transmit an infectious disease that can be fatal under certain circumstances: leishmaniasis.
The disease is caused by flagellated protozoa (leishmania), which live as parasites in their hosts. It occurs in several forms:
- cutaneous leishmaniasis: Here only the skin is affected. The disease is also called Aleppo bump or Oriental bump.
- mucocutaneous leishmaniasis: The parasites have attacked the skin and mucous membrane (especially in the nasopharynx) and then spread to organs in the chest (such as larynx, trachea).
How leishmaniasis progresses in individual cases depends on the type of leishmania and the state of the patient’s immune system.
Death due to anemia
Leishmaniasis can have a very different individual course. In dangerous visceral leishmaniasis, affected individuals often feel tired and listless and have a fever. Liver and spleen are enlarged. When blood counts are checked, pancytopenia – the simultaneous deficiency of white blood cells (leukocytes), red blood cells (erythrocytes) and platelets (thrombocytes) – is noticeable. It occurs when the parasite affects blood formation in the bone marrow.
The lack of erythrocytes causes severe anemia, which is difficult to control. In the worst cases, visceral leishmaniasis leads to death.
Dogs as pathogen dead end
No cab, no disease – right?
Because the pathogens depend on being transported from one host to the next by sandfly cab. No cab, no disease – actually a simple equation. However, this equation no longer works in Germany – thanks to global warming, the heat-loving insects can now also spread in Central Europe:
The first sandfly specimens were discovered in Germany in 1999, and the first sandfly breeding site was identified in 2001/2002. In the meantime, further sites of the pests have been added, mainly in Baden-Württemberg and Rhineland-Palatinate and mainly within towns and villages. Sandflies have also been discovered in other Central European regions (such as France, Belgium and Austria).
But what sandflies can already transmit in Germany are viruses – such as those that cause Tuscany fever (also called Phlebotomus fever or sandfly fever). This is a flu-like illness that can cause meningitis.
Experts believe that with climate change, more sandfly species and with them pathogens will come to Germany in the future.
