Midges and Mosquitoes: The Vector Threat Reshaping Livestock Health Across Two Continents

From Shamonda virus emerging in German cattle herds to 877 human West Nile cases across 15 European countries and lengthening mosquito seasons in Canadian farming regions, vector-borne disease is shifting from seasonal nuisance to structural biosecurity risk — driven by warming temperatures that are extending insect activity, expanding suitable habitat and pushing pathogens into territories with no prior exposure and, in several cases, no available vaccine.

Germany: Shamonda virus arrives in Saxony
Saxony has confirmed its first cases of Shamonda virus in cattle, identified in a cow in the Vogtland district and a herd in the Ore Mountains. The midge-borne virus, a member of the Simbu serogroup, causes sharp declines in milk production alongside fever and gastrointestinal symptoms, with recovery typically taking two to three weeks. Agriculture minister Petra Köpping has urged regular livestock checks and rigorous insect control inside barns. Critically, no vaccine exists. The Friedrich-Loeffler Institute reports the European variant continues to spread across multiple German federal states, with infections confirmed in horses, alpacas, sheep and goats alongside cattle.

Europe: West Nile virus at 877 human cases
The European Centre for Disease Prevention and Control recorded 877 locally acquired human West Nile cases across 15 countries by 26 August. Italy carries the heaviest burden at 428 cases, followed by Greece at 222, where the National Public Health Organisation has flagged intense circulation in Attica. Detections have also occurred in Spain, North Macedonia, Romania and France. The WHO Europe office has urged governments to strengthen mosquito surveillance, warning the transmission season remains active.

Canada: a lengthening season
The Public Health Agency of Canada maintains One Health mosquito surveillance recognising the shared animal-human risk. For producers, heavy infestations reduce grazing time, disrupt resting behaviour and increase stress — directly affecting weight gain and productivity. Alberta’s government identifies equids as among the animals most at risk of serious West Nile illness, with wild birds serving as the primary reservoir.
The economic burden is cumulative rather than dramatic: increased spending on insect control, drainage, shelter and veterinary oversight against already-compressed margins. Warmer temperatures and altered rainfall patterns are extending breeding seasons and expanding habitat, making outbreaks progressively harder to predict.

References:
ECDC West Nile weekly surveillance;
WHO Europe advisory, 24 July 2026;
Friedrich-Loeffler Institute; Saxon Ministry of Health;
Public Health Agency of Canada;
Government of Alberta;
Greek National Public Health Organisation.