Scientists from Kosovo and Germany are working together to combat Hyalomma ticks and the potentially deadly Crimean-Congo Hemorrhagic Fever (CCHF), as climate change allows the tick species to expand further north across Europe.
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The Hyalomma tick, sometimes known as the “giant hunting tick,” was historically found mainly in Africa, Asia and southern Europe. Rising temperatures are now allowing the species to survive farther north, and it has already been detected in Germany and several parts of Eastern Europe.
Kosovo, in southeastern Europe, has been dealing with Hyalomma ticks and CCHF for years.
A Virus That Can Cause Severe Hemorrhagic Disease
Hyalomma ticks can transmit the Crimean-Congo Hemorrhagic Fever virus, a highly pathogenic virus that can cause severe and potentially fatal disease.
In serious cases, the illness can cause widespread bleeding and organ failure. Symptoms can initially resemble influenza, including fever, chills, muscle pain and headaches. As the disease progresses, patients may develop bleeding from the skin, nose and gums, as well as gastrointestinal bleeding.
There is currently no widely available vaccine or specific treatment that reliably cures CCHF, making prevention, surveillance and rapid medical intervention particularly important.
The disease can require intensive care and strict isolation because of the risk of transmission through contact with infected blood and bodily fluids.
From Berlin to Pristina: How the Scientific Partnership Began
Kosovar veterinarian Kurtesh Sherifi first became interested in Crimean-Congo Hemorrhagic Fever in 2005, while completing his studies in Berlin.
At the time, he read about an outbreak in Kosovo in which 11 people had contracted the disease and five had died. Already interested in pathogens that can pass between animals and humans, Sherifi later began working at the Faculty of Agriculture and Veterinary Medicine at the University of Pristina.
However, research resources in Kosovo were limited. The country did not have a high-security laboratory or all the equipment required to conduct advanced research into the virus.
Sherifi eventually established contact with Germany's Bernhard Nocht Institute for Tropical Medicine in Hamburg, one of the country's leading institutions in tropical medicine and infectious disease research.
Among the researchers involved was virologist Petra Emmerich, an expert in highly dangerous pathogens classified in the highest risk groups.
Emmerich first travelled to Kosovo in 2009, where she met Sherifi and began developing the scientific cooperation that would later become a long-term partnership.
Tracking Hyalomma Ticks in Kosovo
A monitoring system was established in Kosovo to track the spread of Hyalomma ticks and the Crimean-Congo virus.
Since 2013, the joint research has received funding through Germany's Biosafety Programme, which supports partner countries in strengthening their ability to deal with biological threats.
The partnership combines German laboratory and diagnostic expertise with Kosovo's direct experience with the disease.
“We have the diagnostic expertise and the necessary resources, but we don't have patients,” Emmerich explained, highlighting the complementary nature of the cooperation.
German researchers regularly travel to Kosovo to work with local medical and scientific experts and exchange information about cases, transmission and prevention.
Why Farmers Face a Particular Risk
Farmers are among the groups most exposed to CCHF in Kosovo.
The risk does not come only from tick bites. Farmers can also become infected when removing ticks from livestock with their bare hands.
If infected blood from an animal comes into contact with even a small wound on a person's hand, the virus can potentially enter the bloodstream.
“This is quite possibly how a large proportion of the infected population in Kosovo became infected,” Sherifi explained.
Public awareness has therefore become an important part of the Kosovo-Germany cooperation.
Sherifi and Emmerich have visited schools to educate students about the risks posed by ticks and how to protect themselves. Protective measures include using tick repellents, wearing long trousers and sturdy footwear, and avoiding areas where ticks are known to be widespread.
Not Every Hyalomma Tick Carries the Virus
Despite the concern surrounding Hyalomma ticks, not every tick carries the Crimean-Congo virus, and most people bitten by a Hyalomma tick do not develop the disease.
The danger comes from infected ticks and contact with infected blood or bodily fluids.
When CCHF becomes severe, patients may require intensive medical care and isolation. Treatment primarily focuses on supporting vital organ functions. The antiviral drug ribavirin has also been used, although its effectiveness in patients with acute disease remains limited.
For this reason, researchers emphasize that prevention and surveillance remain the most effective tools.
Scientists have collected thousands of ticks over the years and conducted seroprevalence studies, using blood tests to identify antibodies from previous infections.
Farm animals are particularly useful for this type of surveillance because the virus does not cause disease in them and they generally remain within defined geographical areas. Finding antibodies in livestock can therefore provide evidence that the virus has circulated in a particular location.
Kosovo Has Seen a Major Decline in Severe Cases
The joint research appears to have coincided with a significant decline in serious CCHF infections in Kosovo.
According to the researchers, the number of serious infections has fallen dramatically over the past decade, with only around five cases recorded in the most recent period compared with approximately 100 cases during the previous decade.
Sherifi and Emmerich see the decline as an indication that years of surveillance, public education and preventive measures have made a difference.
But the threat has not disappeared.
Hyalomma Ticks Are Moving Further North in Europe
Researchers warn that the geographical expansion of Hyalomma ticks is likely to continue.
The species has increasingly been detected in parts of Europe that were previously considered too cold for it to establish itself.
Hyalomma ticks carrying the Crimean-Congo virus have also recently been detected in France, although no human infections have been reported there so far.
“Over the past 13 years, Hyalomma ticks have spread geographically,” Emmerich said, stressing the need for continued monitoring.
For Kosovo and Germany, the cooperation demonstrates how countries with different resources and experiences can work together against emerging infectious diseases.
As climate change alters the geographical range of disease-carrying insects and ticks, the scientific experience gained in Kosovo could become increasingly important for other European countries facing the arrival of Hyalomma ticks and the potential threat of Crimean-Congo Hemorrhagic Fever.