A vector-borne disease is one that moves through a middle man. The middle man in most instances are insects.

Bluetongue is an example of one such disease spread via a vector to the victim. According to Ronan O Neill, Head of Virology at DAFM, the first of the biting midges for 2026 appeared around 2 April. These midges aren’t necessarily infected with bluetongue but the presence of them means the risk period has begun.

The midges that transfer the disease are the female midges. That’s because female midges are the only ones that feed on blood.

Once the midge has bitten an infected animal, the virus is ingested and concentrated in the salivary glands. The virus replicates itself within the vector but air temperatures must be above eleven degrees Celsius for replication.

On wet days, midges will be less inclined to fly and therefore the spreading rates reduce.

This is the only known serotype on the island at the moment, but should other variants arrive, herds will not be covered against them

There are over 30 known serotypes of the bluetongue virus and within the serotypes there are milder and more severe strains. Unfortunately, the vaccination currently being used by farmers will only cover for the number three serotype.

This is the only known serotype on the island at the moment, but should other variants arrive, herds will not be covered against them.

The morbidity rate of bluetongue according to Ronan is under 10%, but the real problems are infertility, abortions and malformations.

Bulls are another high-risk spreader of the virus with transfer through the semen a big problem.

For herds that haven’t already, vaccinating bulls before they are let out with cows will be of benefit in reducing the risk of disease incidences.

Vector-borne diseases are something Ronan believes will become even more problematic into the future, as average temperatures continue to rise.

2024 was noted as the warmest year on record in the EU with 2025 the third warmest on record.