Des vaches dans un pré

Everything you need to know about epizootic haemorrhagic disease

Epizootic haemorrhagic disease (EHD) is a viral disease that was first detected in France in 2023. Its spread is a direct consequence of climate change, which enables the midge vectors of the disease to survive in our regions. Which animals does it affect? What are the symptoms? Is there any treatment? Can this disease be transmitted to humans? All the answers to these questions are in this article.

What is epizootic haemorrhagic disease? 

Epizootic haemorrhagic disease (EHD) is a non-contagious viral disease that only affects certain animals.

It cannot be transmitted to humans. 

How is epizootic haemorrhagic disease transmitted?

Only midges of the genus Culicoides can transmit the disease, by biting a healthy animal after having previously bitten a sick animal.

The disease is not contagious: a sick animal cannot directly infect another animal.

Which animals are affected by epizootic haemorrhagic disease?

EHD infects:

  • primarily cattle and deer,
  • and sheep more rarely.

What are the symptoms of epizootic haemorrhagic disease?

In cattle, this disease causes fever, anorexia, lameness and respiratory distress. It is fatal in less than 1% of cases.

Small ruminants – sheep and goats – can also carry the virus but so far, symptomatic cases have only been detected in sheep.

The vast majority of animals recover and return to normal health after a few days or weeks of rest and treatment.

On the other hand, the mortality rate in deer can exceed 90%.

Can epizootic haemorrhagic disease be transmitted to humans?

No, it cannot be transmitted to humans.

Where did EHD originate?

The virus was first discovered in the United States in 1955, and has since spread to Asia, Australia and Africa. It was first detected in Europe in 2022 (in Italy and then Spain), before reaching France in 2023.

Its spread is a direct consequence of climate change, which enables the midge vectors of the disease to survive in our regions.

What is the epidemiological situation in France?

To monitor the epidemiological situation, visit the Ministry of Agriculture's website.

Is there any treatment for epizootic haemorrhagic disease?

The virus has seven different serotypes (serotypes 1 and 3 are identical). The virus that arrived in Europe belongs to serotype 8. No vaccine is currently available against this serotype. The vaccines used in Japan and the United States were developed for other serotypes and will not be effective against this one. Manufacturers are therefore considering developing a suitable vaccine for this serotype.

In the meantime, other measures are being taken to curb the spread of the virus, but they only have limited effectiveness:

  • testing animals and banning the transport of ruminants from infected areas,
  • treating animals with insecticides.

What are the authorities doing to prevent epizootic haemorrhagic disease?

Zoning measures have been put in place: animals can only leave an infected zone after having been tested by PCR.

What is ANSES doing about epizootic haemorrhagic disease?

ANSES's Laboratory for Animal Health is the reference laboratory for this disease in France and for the World Organisation for Animal Health (WOAH). In this role, it has identified the virus, sequenced the viral genome, validated PCR tests and set up a network of official laboratories capable of identifying cases.