Hyaloma ticks that transmit the Crimean-Congo virus spread northward and German-Kosovan cooperation to combat it

This tick can detect its victims from a distance of up to 200 metres. Unlike many tick species, which hide in the grass waiting for their host to pass by, the Hyaloma tick actively pursues its prey, whether it is cows, sheep or even humans, before attaching itself to them and biting them.

In the past, the Hyaloma tick was spread mainly in Africa, Asia and southern Europe, but climate change has helped it expand into new areas. As temperatures rise, this tick is finding suitable conditions for survival and reproduction in areas located north, and it has already been spotted in Germany and a number of Eastern European countries. As for Kosovo, it has been considered for years to be one of the most prominent hotspots for its spread.

The situation would not be so bad if it were not for the fact that the Hyaloma tick is a carrier of a highly contagious virus, the Crimean-Congo virus (Orthonairovirus haemorrhagiae). This virus can cause what is known as Crimean-Congo hemorrhagic fever, whose symptoms are similar to those of the Ebola virus and the Marburg virus. These viruses are capable of destroying blood and lymphatic vessels, which may lead to internal bleeding that leads to death.

The beginning of a partnership between Germany and Kosovo

The story of German-Kosovar cooperation began in 2005, when veterinarian Kurtis Sharifi, who was then about to complete his doctoral thesis in Berlin, read news about an outbreak of Crimean-Congo fever in his country, Kosovo. It was reported that 11 people were infected with the disease and five of them died. The news piqued the interest of Sharifi, who was focusing his research on zoonotic diseases, that is, those that spread from animals to humans. The Crimean-Congo fever virus quickly attracted attention as a scientific topic with many research questions and challenges.

Sharifi got a job at the Faculty of Agriculture and Veterinary Medicine at the University of Pristina. But the budget allocated to science is limited. In Kosovo, a small country with a population of only about 1.6 million people, there is neither a high-security laboratory nor the necessary equipment to diagnose the Crimean-Congo virus.

Therefore, Kurtish Sharifi turned to the Bernhard Nocht Institute for Tropical Medicine in Hamburg, where the institute has the necessary equipment in addition to specialized researchers, including Petra Emmerich, a virologist at the Bernhard Nocht Institute for Tropical Medicine who specializes in diagnosing risk category 4 viruses, which the Crimean-Congo virus is classified as.

Virologist Emmerich was also serving as a reserve officer in the German army, which pays particular attention to viruses that are highly dangerous due to their potential to be misused as biological weapons. In 2009, she was sent to Kosovo in this capacity, where she met veterinarian and researcher Kurtis Sharifi. This meeting formed a starting point for scientific cooperation that later contributed to enhancing understanding of the Crimean-Congo fever virus and combating its spread.

Cooperation between the two sides quickly developed into an intensive exchange of experiences and researchers. In Kosovo, work has begun on establishing a specialized system to monitor the spread of hyaloma ticks and diagnose the Crimean-Congo fever virus. In 2013, this scientific cooperation gained new momentum after receiving support and funding from the Biosecurity Program of the German Foreign Ministry, which helped expand research and strengthen local capabilities to confront the disease.

Benefit from mutual experiences

“It's a process of give and take,” is how Petra Emmerich sums up the partnership. “We have the diagnostic expertise and resources for it, but we don't have the patients.” That is why the virologist regularly brings with her doctors from Germany who exchange experiences with doctors in Kosovo.

Awareness and prevention were another key pillar of German-Kosovar cooperation to combat Crimean-Congo fever. Farmers in Kosovo are among the groups most vulnerable to infection with the virus, not only due to the bites of infected ticks, but also as a result of removing ticks from the bodies of their livestock with their bare hands. When the blood of an infected animal comes into contact with a small wound on the hand, the virus can be transmitted to humans.

Kurtis-Sharifi says a large proportion of infections in Kosovo likely occur this way. Therefore, efforts were not limited to scientific research and laboratories, but rather extended to the field, where Sharifi and virologist Emmerich participated in awareness campaigns within schools and local communities to introduce the dangers of the virus and means of prevention.

These measures included the use of tick repellents, and wearing long pants and closed shoes while working in areas susceptible to its spread. Prevention is particularly important because there is not yet an approved vaccine or direct specific treatment for Crimean-Congo fever, which makes avoiding infection the first and most important line of defense.

Why is Crimean-Congo fever so dangerous?

It is true that most infections do not cause any symptoms. “But if I got sick, it would be very serious,” Emmerich says. Symptoms begin with non-specific flu-like symptoms such as fever, chills, limb pain, and headache. In severe cases, bleeding occurs in the skin, nose, and gums, in addition to bleeding in the digestive system, and this may lead to organ failure. Patients must receive intensive medical care and, most importantly, must be isolated because they are highly contagious.

In addition to treatment in the intensive care unit, which aims primarily to maintain vital functions, Crimean-Congo fever patients receive the antiviral drug “ribavirin.” But “ribavirin is almost ineffective in patients in the acute phase,” Emmerich says. This result was not limited to studies only. “We have personally witnessed this in the cases we have treated in Kosovo.”

Awareness and monitoring pay off

It is therefore particularly important to monitor the spread of ticks and the virus and also to avoid certain areas when in doubt. For this purpose, researchers not only collected thousands of ticks over the years, but also conducted what is known as studies of the rate of prevalence of antibodies in the population, or what is known as “seroprevalence,” in which the blood is tested to detect antibodies to the virus. This can determine whether humans or animals have been exposed to the virus.

Sharifi says that domesticated animals are particularly suitable for this purpose, as the virus does not affect them. Unlike wild animals and humans, these animals are mostly found in a clearly defined area. If the presence of antibodies is detected in the blood of these animals, it becomes clear that the virus is spreading in that area.

In Kosovo, infection numbers have declined sharply over the past ten years, reaching only five cases in total. For comparison: in the ten years before that, 100 cases of infection were documented. Sharifi and Emmerich consider this a success for their work.

However, both expect an increased spread of ticks and the virus. In France, for example, a Hyaloma tick infected with the Crimean-Congo virus was discovered. No human infection has been recorded so far. “Over the past 13 years, hyaloma ticks have really spread geographically,” Emmerich says. “As a virologist, this is a concern and should be monitored closely.”

Therefore, Kurtis Sharifi believes that it is important to transfer everything he has learned from the German researchers and with them to other countries that do not yet have much experience in monitoring and diagnosing ticks and the Crimean-Congo virus. Like North Macedonia and Albania for example. These are new areas where ticks and the virus are currently spreading.

Prepared in Arabic by: M.A.M