Ticks taken from migratory birds were examined in a scientific study

The study, under the coordination of Koç University İş Bankası Infectious Diseases Research Center (KUISCID) and involving researchers from UCLA, Koç University, Istanbul University-Cerrahpaşa, Marmara University and Tekirdağ Namık Kemal University, aims to reveal the movement of disease agents through ticks carried by migratory birds and to shed light on the risks that may arise for public health in the early stages.

As part of the scientific study that started in 2025, birds on the migration route are caught and ringed at the Bird Ringing Station in Avcılar, Istanbul. While the ticks on the birds are collected, the completed birds are released back into the wild.

Ticks taken from birds are delivered alive to Marmara University twice a week. Here, ticks are examined morphologically under a microscope and identified at genus and species level.

While it is recorded which tick was taken from which bird, the identified samples are later prepared to investigate the disease agents.

The prepared samples are subjected to molecular analysis in KUISCID laboratories. Nucleic acids, especially DNA and RNA, are extracted from ticks, and following the enrichment and library preparation processes, sequencing is performed. The data obtained is evaluated with bioinformatic analysis and viral and bacterial factors that may be found in ticks are investigated.

While the analysis process of a sample takes approximately 1-1.5 months, the study does not focus only on the CCHF factor. Scientists are also investigating whether other viral and bacterial disease agents are found in ticks carried by migratory birds.

Within the scope of the project, it is aimed to create a more comprehensive data set on the movement of disease agents by comparing samples collected in different seasons and years during the migration of birds to Europe in spring and to Africa in autumn.

Stating that migratory birds are important not only ecologically but also in terms of transporting disease agents between continents, the researchers are carrying out the study within the scope of the "One Health" approach, which considers human, animal and environmental health together.

"We have been collecting ticks from birds regularly for two years."

Istanbul University-Cerrahpaşa Vocational School of Forestry, Department of Forestry, Head of Hunting and Wildlife Program, Lecturer. See. Dr. Ergün Bacak said that the project started in March 2025.

Stating that banding studies are also important in understanding the movement of diseases between continents, Bacak said, "We have been collecting ticks from birds regularly for two years. Last year, we banded around 10 thousand birds and collected approximately 8 thousand ticks from the birds. Birds do not only migrate themselves, they can also carry the parasites, especially ticks, they carry on them from one continent to another. Therefore, it is important to know which ticks are on the birds and which disease agents these ticks carry." he said.

Explaining that the ticks were taken alive from the birds and delivered to Marmara University, Bacak said that this was especially important for the research of RNA viruses.

"This study is very important in terms of understanding the risk of a possible epidemic in advance."

Stating that one of the main focuses of the study is CCHF, Bacak noted that ticks associated with this disease can be transported to different regions through migratory birds.

Bacak said, "CCD is very important to us because there are Hyalomma species associated with this disease. We do not only collect Hyalommas. We also collect different tick species such as Ixodes and Haemaphysalis found on birds. Because we cannot know in advance which tick carries which disease agent. What we are trying to do here is not to investigate a disease after it occurs. In the early period, we are trying to see which factors are carried from where to where." shared his knowledge.

Noting that birds move from one continent to another and carry ticks on them, Bacak said, "These ticks can also carry some disease agents. This study is very important in terms of understanding the risk of a possible epidemic in advance. Today we are focusing on CCHF, but tomorrow we may encounter other viral or bacterial disease agents. We are trying to evaluate this whole system together. We need to see that the ecosystem is a whole. If you examine the birds, you see their parasites, if you examine the parasites, you also see the disease agents and the possibility of these factors reaching humans." he said.

"A significant part of the work has been completed"

Marmara University Faculty of Health Sciences, Head of Basic Health Sciences Department, Prof. Dr. Ayşen Gargılı Keleş stated that the project developed as a continuation of previous joint studies of different universities.

Explaining that the tick is a vector and can play a role in carrying disease factors between different living things, Keleş stated that migratory birds can be an important carrier in this process.

Keleş stated that a significant part of the work has been completed and is now in the final stage and continued as follows:

We are trying to determine which disease agents these ticks carry. We don't want to just mention tick species here. We want to evaluate together which bird species carry which ticks, in which regions these ticks are found and which pathogens they carry. If any risk arises, it will be possible to map it, make the necessary plans and share it with the relevant institutions. It is possible for a disease agent to be carried from one continent to another and then be seen in humans. Therefore, it is necessary to identify risks and be prepared before the disease occurs.

Within the scope of the study, it was revealed that the Asian longhorn tick settled in Istanbul.

Dr. from Marmara University, Faculty of Health Sciences, Department of Basic Health Sciences. Faculty Member Gürkan Akyıldız explained that the morphological characteristics of the ticks delivered to the laboratory were first examined under a microscope and identified at the species level.

Noting that they also recorded which tick came from which bird, Akyıldız said, "In this way, we have data on both the tick type and which bird this tick was found on." he said.

Explaining that after determining the type of ticks, they made the samples suitable for pathogen research, Akyıldız stated that they were later sent to Koç University KUISCID laboratories and molecular level examinations were carried out there.

Akyıldız stated that they obtained an important finding during the study, especially in terms of Haemaphysalis longicornis, known in Turkish as the Asian longhorned tick, and said:

The Asian longhorned tick is an important species for us. It was detected in Istanbul in 2024, and the study on it was published in 2025. As part of our UCLA project, we retrospectively re-examined all the ticks we had previously collected from birds. We also saw the larva and nymph stages of this species on birds. We also encountered nymphal stages on the vegetation in the relevant region. Thus, we are not talking about just one individual. We obtained findings showing that the species can continue its life cycle in the region. The important aspect of our study is that it reveals evidence that this species, which was previously detected in Turkey, has now become established in Istanbul. Our article about this study was published in Parasites&Vectors magazine.

Stating that the Asian longhorn tick is an invasive species originating from East Asia, Akyıldız said that this species, which can settle in different geographies, should be closely monitored for the disease factors it may carry.

Akyıldız said, "The important point for us is to reveal which disease agents this tick, which has newly settled in Türkiye, can carry here. It would not be right to immediately say that this tick carries this disease. What we are trying to do is to investigate this. The fact that the tick has settled in Türkiye shows that it should be investigated in terms of the pathogens it carries or can carry with it." he said.

IT WORKS LIKE AN EARLY WARNING SYSTEM

KUISCID Founding Director and infectious diseases specialist Prof. Dr. Önder Ergönül emphasized that one of the main questions of the project is to understand why and how the CCHF virus emerged in Türkiye.

Stating that there are scientists working on these issues at UCLA in the United States, Ergönül said, "We systematized this study together with the teams in Türkiye. We created an organized system that includes regular monitoring of birds, collection of ticks, determination of their species and then examination in the laboratory." he said.

Ergönül emphasized that the project does not only research existing diseases and continued his words as follows:

We want to see which viruses are in the ticks that came with birds of African origin. We want to compare these with viruses in Türkiye. I wonder if birds bring a new virus or a new type of virus? If so, where does this factor spread? We want to reveal these. In 2016, CCHF cases emerged in Spain. It was revealed that ticks carried by migratory birds from Africa were behind this. This example shows us how migratory birds and the ticks they carry can play a role in spreading diseases to new geographies. We are not just looking for Crimean Congo. We may also find other viruses that we did not know about before. For this reason, our work actually works like an early warning system.

Stating that the project has created an important data set with field and laboratory studies carried out for approximately two years, Ergönül said that it is planned to present more comprehensive results about birds and ticks by the end of 2026.

Ergönül stated that the data obtained in the project is aimed to contribute to the monitoring of diseases before they occur, and stated that scientific work can strengthen Türkiye's preparedness capacity for epidemics in the long term.

Prof. Dr. Ergönül said, "Our aim is not to go after a disease after it occurs. It is to see the risks before it occurs. If we can regularly monitor birds, ticks and the factors they carry, we may have the chance to detect diseases that may arise in the future earlier." made his assessment.

Assoc. Prof. from KUISCID. Dr. Mert Ahmet Kuşkucu also explained that the ticks, whose species were identified at Marmara University, were later delivered to KUISCID laboratories for molecular analysis.

Noting that the main purpose here is to reveal whether there are any viral or bacterial agents in these ticks, Skeptic said, "We are primarily looking at the CCHF virus. However, thanks to the advanced technology we use, we are not just looking for a single virus. We can extract the DNA and RNA of ticks and perform a much broader screening. With climate change, changes can be seen in the migration routes of birds and the distribution of some vectors such as ticks. These creatures can also carry some viral factors. Therefore, this is what is important for us." "To be able to follow the mobility in advance." he said.

Explaining that they first extract nucleic acids, that is, DNA and RNA, from the tick, Kuşkucu said, "Then we go through the enrichment and library preparation stages. Then, sequencing is done. Then, we investigate what these sequences belong to with bioinformatic analysis. It can take about one to one and a half months for a sample to be thoroughly analyzed and finalized." he said.

Kuşkucu stated that the detection of new tick species during the study could also serve as an early warning for new disease agents and said, "Seeing that a new tick species has settled in Türkiye is an important early warning for us. Because we need to know which viral or bacterial agents that species can carry. For this reason, we do not only look at the diseases we know today. We are also investigating whether there are other factors in the samples." he said.