Health. What is Crimean-Congo hemorrhagic fever, detected in France?

Health.  What is Crimean-Congo hemorrhagic fever, detected in France?

In a press release dated October 24, the National Agency for Food, Environmental and Occupational Health Safety (ANSES) announced that for the very first time, the Crimean-Congo hemorrhagic fever virus ( also abbreviated FHCC) had been detected in France.

It was found in ticks that bit cattle in the Pyrénées-Orientales. We explain what you need to know about this disease.

What are the symptoms ?

Crimean-Congo hemorrhagic fever is an illness caused by a virus of the Nairovirus family (whose name comes from a malady of the sheep of Nairobi, Kenya). It can cause numerous and varied symptoms that appear suddenly: “fever, myalgia (muscle pain), digestive disorders, dizziness, stiffness and pain in the neck, back pain, headaches, tenderness of the eyes and photophobia (feeling of discomfort caused by light),” explains Public Health France.

If in humans it is most often limited to fever and digestive disorders, CCHF can sometimes take more serious forms, including significant hemorrhage, which can lead to the death of the infected person. According to Public health Francein some countries where the virus is widespread, the risk of death can reach 30%. The World Health Organization (WHO) suggests a fatality rate of up to 40%.

There is currently no vaccine against Crimean-Congo hemorrhagic fever. Treatment of the disease is thus based solely on treating its symptoms, which generally disappear around ten days after their appearance in treated people.

How is this disease transmitted?

The disease is endemic in several regions of the world such as Africa, the Balkans, the Middle East and Asia. But also “in countries below the 50th degree of north latitude”, notes the WHO. This is in fact the geographical limit of the main vector species of the FHCC, a tick.

If several species of ticks can carry the disease, those of the Hyalomma genus – both male and female – are the main vectors. Nevertheless, ” bite frequency of human beings is supposed to be low, these ticks having no particular appetite for humans,” explains Public Health France.

However, the virus can spread to humans when a person is bitten by an infected tick. It can also be transmitted “by contact with blood or tissues of infected animals, during or immediately after slaughter”, notes the WHO, although this is rarer. This type of infection most often occurred among breeders, slaughterhouse employees or veterinarians.

The infection is not transmitted by air or by consuming milk from animals (cattle, goats, etc.) bitten by ticks carrying the disease.

The incubation period for the CCHF virus is rapid (one to three days) when the infected person is infected via a tick bite.

What do we know about the case discovered in France?

Cases of Crimean-Congo hemorrhagic fever are detected every year in our Spanish neighbors, according to ANSES. Several patients died from it.

But at the beginning of October, the Center for International Cooperation in Agricultural Research for Development (CIRAD) detected the virus responsible for CCHF for the first time in France, in Hyalomma ticks taken from cattle in the Pyrénées-Orientales.

“No case (of FHCC) has been detected in humans in France to date”, however tempers ANSES.

Should we be worried about the spread of the virus?

To limit the risks of transmission, ANSES and Public Health France point out that basic precautions exist to avoid tick bites, particularly among hikers, breeders and farmers.

Certainly, three species of Hyalomma ticks have been present in France, particularly in Corsica for several decades, but also throughout the Mediterranean. But most French territories are currently spared from its presence. Furthermore, in this season, the risks are low: the Hyalomma tick “is only active in the spring between April and July”, assures Public Health France.

According to ANSES, cases of Crimean-Congo hemorrhagic fever could increase in France thanks to global warming. “This risk is all the more likely as the geographic extension of the ticks’ implantation zone should be favored by ongoing climate changes. Hyalomma ticks actually like dry climates and hot periods. This is why in France we find them preferentially in the scrubland or scrubland around the Mediterranean, unlike other ticks which are more forest-based,” explained Elsa Quillery, animal health epidemiologist at Anses, last June.

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