As a deadly tick-borne disease spreads across the continent, the European Union (EU) is looking for new testing methods and a vaccine for the infection.
A 62-year-old man was bitten by a tick while walking in the fields of Spain. Two days passed, his condition improved and the man was taken to a hospital in Madrid. He died on the ninth day of his illness.
This happened in 2016. It turns out that this was the first death from Crimean-Congo hemorrhagic fever in Spain. This tick-borne disease begins with flu-like symptoms and can often lead to organ failure.
Spread to the north
"Because of climate change, longer and drier summers, ticks are moving northwards across Europe," said Professor Ali Mirazimi, a virologist at Sweden's Karolinska Institute.
The first case was difficult for Spanish doctors to diagnose because hemorrhagic fever did not exist in Western Europe. The nurse of the hospital where this patient was was also infected with the virus. But after several weeks in intensive care, she survived.
in 2022 In July, another Spaniard was hospitalized with the same illness. Now scientists warn that Crimean-Congo hemorrhagic fever, which can kill about 10-40 percent of of the infected, spreading to the north and west of Europe.
It is caused by a virus carried by a type of tick that feeds on the blood of small animals early in life. Later they move on to larger animals and humans.
Crimean-Congo hemorrhagic fever was first described in 1944. an outbreak of disease among soldiers in Crimea, on the northern coast of the Black Sea. Occasional outbreaks are still reported today, particularly in Africa, Eastern Europe, Turkey, Central Asia and India. But now this disease is spreading all over the world.
One infected tick can lay thousands of infected eggs. Young ticks feed on the blood of small mammals such as rabbits, as well as birds.
It is the birds that allow ticks to travel and the virus to reach new areas.
Dangerous visitors
"When we find infected ticks, we know that sooner or later there will be an outbreak," Mirazimi said.
Currently, ticks carrying the virus can also be found in, for example, Italy, but not a single outbreak of this disease has been recorded here. His arrival in a new country is dangerous because doctors may find it difficult to diagnose a disease they have not seen before.
"We don't have reliable treatments," admits A. Mirazimi. "There are no good antiviral drugs, no approved vaccine, and knowledge about this disease is not complete."
This means that doctors have no choice but to rely on general medical treatment, which consists of fluids, drugs and, if necessary, intensive care.
Another challenge is that a person infected with hemorrhagic fever can transmit the virus to their loved ones through saliva and sweat. This poses a risk not only to family members but also to the doctors and nurses treating the person.
So the earlier this infection is diagnosed, the better, as it allows for proper isolation of the patient.
Testing trouble
All this underlines the importance of the VHFMoDRAD project led by A. Mirazimi, whose goal is to discover ways to diagnose this disease. This initiative, funded by the EU and industry representatives, was implemented in 2019-2022.
One resulting method uses polymerase chain reaction, or PCR, testing, which typically requires sophisticated laboratory equipment and highly trained personnel. But a much simpler and faster machine is used in this process.
Another approach is simple-to-use tests similar to those used during the COVID-19 pandemic.
An additional benefit of these tests is that they help detect not only Crimean-Congo, but also other viral hemorrhagic fevers. Infections caused by Ebola, Marburg and Lassa viruses also belong to this group of diseases. Back in February and March of this year, two separate outbreaks of Marburg virus were reported in Equatorial Guinea and Tanzania.
But the most famous of them is the Ebola virus. During 2014 More than 28 people have been infected with the virus since the outbreak began in Guinea. It spread to seven more countries and by the end of the outbreak in 000. claimed more than 2016 lives.
According to Professor Roger Hewson, an expert on Crimean-Congo haemorrhagic fever and other haemorrhagic viruses at the Liverpool School of Tropical Medicine, outbreaks of haemorrhagic fever need to be identified as soon as possible.
"Their mortality rate is very high," said Hewson, who collaborated with Mirazimi on the VHFMoDRAD project. "With a quick diagnosis of this disease, patients can be quickly isolated, thus saving lives."
Crimean-Congo hemorrhagic fever is not the only type of viral infection that spreads through close contact, such as through saliva or sweat. Therefore, the infection can be transmitted during, say, a medical examination or a funeral.
This happened in West Africa during the Ebola outbreak. Most importantly, VHFMoDRAD found a way to deactivate any virus present in the blood sample, making the tests safer.
In the past, deadly Ebola outbreaks in isolated African communities were likely to go unreported. But today, better transport links allow such viruses to spread quickly over large urban areas.
Once diagnosed, patients can often be saved with the right treatment.
In Turkey, Crimean-Congo hemorrhagic fever is so common that doctors can easily detect it and provide life-saving care to patients. As a result, according to scientists, the mortality rate from this virus in Turkey is relatively low - 7 percent.
Fierce fight
Viruses that cause hemorrhagic fever are usually spread among animals, such as bats (this is the case with Ebola and Marburg), and rarely spread to humans. But when this happens, many people's immune systems fight the invader so fiercely that fatal organ damage occurs.
"Viruses are often cleared from the body after a few weeks, but the bleeding is caused by an immune response," Hewson explained.
His lab studies the infection to understand the immune response it provokes. This study is related to another project, CCHFVaccine, to develop a vaccine against Crimean-Congo hemorrhagic fever.
This initiative, also implemented in Sweden, started in 2017. and must end in June of this year. Two types of vaccines have been sought so far.
Vaccine safety trials are expected to be conducted in Sweden at the end of this year or in 2024. at the beginning Then, phase III trials proving the vaccine's efficacy could be conducted in Turkey.
The vaccine would target people most at risk. These are doctors, nurses, veterinarians, animal slaughterhouse workers and maybe even tourists in endemic areas. Although Crimean-Congo hemorrhagic fever is a rare disease in Europe, it still poses a risk. "Everyone who gets infected has huge consequences," Mirazimi said.
