Crimean-Congo hemorrhagic fever is a tick-borne disease with a case fatality rate of up to 40%. Present in Africa, the Balkans, the Middle East and Asia, it could also, depending on global warming, occur in France.
Present on the WHO list of priority diseases, Crimean-Congo haemorrhagic fever (or CCHF) is a disease caused by a virus (Nairovirus) transmitted by ticks. The fatality rate varies from 10 to 40%.
After an incubation of a few days, the onset of symptoms is brutal, with fever, myalgia (muscle pain), dizziness, stiffness and neck pain, back pain, headache, eye tenderness and photophobia (feeling of discomfort caused by light). If for the moment the pathology is endemic on the African continent or in the Middle East, its arrival in France could become a reality.
The impact of climate change
The tick vector of the disease, the Hyalomma tick, has been present for several decades in Corsica and since 2015 on the Mediterranean coast. And because of migrating birds from Africa.
A dozen autochthonous human cases of CCHF have been reported in Spain since 2013, some of which have caused the death of the patient. “If no human case has been detected for the moment, the risk of appearance of cases of CCHF in France is possible“, explains Elsa Quillery, coordinator of scientific expertise at ANSES. “This risk is all the more probable as the geographic extension of the tick implantation zone should be favored by the current climate changes. Hyalomma ticks indeed like dry climates and hot periods. This is why, in France, they are found preferentially in the scrubland or the maquis around the Mediterranean, unlike other ticks which are rather forest.”
Contrary to what exists for mosquitoes, no national monitoring system is organized for ticks as they transmit serious diseases such as CCHF but also Lyme disease. ANSES therefore calls for the implementation of surveillance of ticks of the Hyalomma genus on a national scale, prioritizing the geographical areas most at risk.
To note : There is currently no vaccine. The management of Crimean-Congo hemorrhagic fever is mainly based on symptomatic treatment.