One in five ticks in the Netherlands is infected with the Borrelia burgdorferi bacteria, the cause of Lyme disease, known as Lyme for short. Every year, the Dutch suffer an estimated one and a half million tick bites and more than 25,000 people get Lyme. Infectiologist Joppe Hovius is working on a vaccine that targets ticks.

An infection with the Borrelia bacteria is usually betrayed by a red circle around the bite, the first manifestation of Lyme. The RIVM estimates that every year 1,000 to 2,500 people in the Netherlands have long-term complaints after Lyme disease.

Apart from Borrelia burgdorferi, the sheep tick transmits at least six other pathogens - viruses, parasites and bacteria. Borrelia miyamotoi, Anaplasma, Babesia, Rickettsia, Neoehrlichia, and also the tick-borne encephalitis virus. Research shows that about one in three of Dutch ticks contains at least one of these pathogens. But it is not known exactly how often people get sick. Only a few cases of illness are known, but maybe that is because we are not paying close attention to them.