Babesiosis is a disease caused by the Babesia parasite. It is most common in roe deer, rats and cattle. The Babesia parasite is related to parasites of the genus Plasmodium, which cause malaria. It infects the red blood cells. 

How you become infected with babesiosis

You can get babesiosis  from the bite of a deer tick (Ixodes scapularis) or castor bean tick (Ixodes ricinus) that carries the Babesia parasite. These ticks, in turn, became infected with the parasite when they fed on infected animals. 

The disease can also be transmitted through a blood transfusion, although this is rare.  The Babesia parasite cannot be transmitted through human contact. 

What are the symptoms? 

Many of those infected will get no symptoms and never notice that they are carriers. Those who do get symptoms will experience flu-like symptoms such as cold shivers, a fever, sweating, nausea and fatigue. Because the Babesia parasite infects and destroys red blood cells, it can in some cases lead to haemoglobinuria, jaundice and hemolytic anaemia. 

Infected people who develop symptoms usually do so within a week of infection. An infection can only be diagnosed conclusively through a blood test. 
Patients who have had their spleen removed, have a weakened immune system or have an underlying condition run a greater risk of serious illness.

How common is it? 

In the Netherlands, babesiosis in humans is extremely rare. That said, it is a known fact that a small proportion of the Dutch tick population carries the parasite. The first case of a human babesiosis infection caught in the Netherlands was reported in September 2023.  

How can you avoid babesiosis? 

Avoiding tick bites is key. Because ticks can also transmit other diseases (such as Lyme disease), we recommend checking your body for ticks whenever you return from spending time in nature and remove any ticks you find as soon as possible.