Ireland is currently entering a “higher risk period” for the transmission of the bluetongue virus (BTV), according to the Department of Agriculture, Food and the Marine (DAFM).

The latest bluetongue virus update has been issued by the national disease control centre at the department.

The disease could spread to Ireland through import of infected animals, infected foetuses or wind dispersal of infected midges from mainland Europe.

The virus can also be transmitted via infected germinal products (semen, ova and embryos).

Bluetongue virus is spread by infected biting midges (Culicoides species) which are generally most active between April and November.

The virus update detailed that “it is critical that all livestock farmers maintain vigilance for any suspicions of this disease”.

It added that it is “especially” important at this time of year as “temperatures continue to rise during spring and summer.

The department has urged livestock owners to report of BTV suspicions to their local Regional Veterinary Office (RVO) without delay.

Ireland is currently free of BTV, which is a viral disease of ruminants and camelids that continues to be of widespread concern across mainland Europe.

Bluetongue virus (BTV) is a notifiable exotic disease that infects ruminant animals (such as sheep, cattle, goats and deer) and camelids (such as llama and alpaca).

Bluetongue does not affect human health or food safety. However, if bluetongue virus entered Ireland it would have serious trade implications for live animals and germinal products.

Bluetongue cases in Europe

Since the first BTV-3 vaccine produced became available in May 2024, two other BTV-3 vaccines produced have also been given emergency authorisation by the Dutch authorities for use in the Netherlands.

The decision in the Netherlands was made to begin with vaccinating sheep on farms by veterinary surgeons in May 2024, to reduce clinical disease and mortality associated with the disease.

Cows grazing in the Netherlands Nitrates derogation

Although vaccination is not mandatory, the willingness by sheep farmers to vaccinate
has been high (approximately 95%), according to the Dutch Minister of Agriculture.

Two cases of BTV-3 have been detected in the Netherlands in the Gelderland region in June 2024.

However, since 2023, the total number of confirmed cases of BTV-3 epidemic is 5,996.

Bluetongue serotype 3 (BTV-3) continues to pose a risk in northern Europe. BTV-1, 4 and 8
continue to circulate in southern Europe.

There is no evidence that bluetongue virus is currently circulating in midges in Great Britain, and there are no current bluetongue control zones in force.

There have been 126 bluetongue cases (119 cattle, and seven sheep) reported in England on 73 premises in four counties. No additional cases have been reported since March.

In Belgium, there were seven outbreaks of BTV-3 confirmed on farms in Antwerp, while there have been 47 cases in Germany, the last being in February 2024.

BTV-3 has not been reported in France, but two strains of BTV-8 have been confirmed. However, existing vaccines against BTV-8 are thought to remain effective against this new strain.

Bluetongue continues to circulate in Spain despite a vaccination and an eradication programme. The Spanish authorities have put into place movement restrictions in several BTV affected areas to limit trade and improve surveillance.

BTV-4 has been confirmed in cattle and sheep in northern and central Spain.

Multiple outbreaks of BTV-3,4,8 have been reported across Sardinia in Italy, while in Sicily there were outbreaks of BTV-4.

In mainland Italy, there have been multiple reported outbreaks of BTV-4 and a single outbreak detected BTV-8 in December 2023 for the first time.