West Nile reviews highlight horses’ role in Europe’s surveillance
A new review in Pathogens makes a familiar veterinary point more explicit: in Europe’s West Nile virus landscape, horses aren’t just spillover hosts, they can be useful sentinels when surveillance systems are built to use them that way. The paper, published in 2026, reviews evidence from 2010 through December 2025 and argues that equine surveillance should sit inside a One Health framework that links veterinary findings with human case reporting, bird surveillance, and mosquito monitoring. (mdpi.com)
That framing comes as West Nile virus remains a recurring European concern, with transmission shaped by the interaction of migratory birds, Culex mosquitoes, climate, land use, and local surveillance capacity. The review notes that Europe’s surveillance architecture already reflects this multi-sector approach, with ECDC, EFSA, and WOAH contributing to the broader reporting ecosystem. EFSA says its joint surveillance with ECDC covers infections in humans, equids, and birds, and that monthly automated reports were issued from July through December 2025 to support timely situational awareness. (mdpi.com)
The authors’ core argument is that horses can help identify local viral circulation, but the value of that signal depends on how quickly and accurately cases are recognized. That’s where the companion Veterinary Sciences review becomes relevant: it emphasizes that diagnosing West Nile infection in horses is not straightforward because viraemia is brief and low, reducing the utility of molecular assays, while flavivirus serology can be confounded by cross-reactivity. In other words, the sentinel role is real, but only if veterinary systems have access to appropriate testing strategies and interpretive expertise. (mdpi.com)
The European paper also points to country-level examples that support the surveillance case. In Italy, the authors note, the national arbovirus plan calls for continuous monitoring of human and animal health plus systematic mosquito trapping during the May-to-October transmission season, and during the 2022 epidemic, detections in mosquitoes and birds preceded human or equine cases by weeks. The review also highlights Greece’s integrated approach, which combines human case reporting with serologic testing of sentinel horses, follow-up of nearby equines, and bird surveillance. These examples suggest that horses are most valuable not as isolated indicators, but as one layer in a stacked surveillance model. (mdpi.com)
Recent European surveillance data reinforce why that matters. EFSA’s December 2025 monthly report says outbreaks in birds and/or equids were reported in 116 regions across 11 countries, and that equid outbreaks in June, July, and August 2025 exceeded the 10-year monthly average. The same report says 2025 animal reporting included first-ever ADIS notifications from Belgium for wild birds, a first equid outbreak notification from the Netherlands, and a first animal outbreak report from Cyprus. Those shifts don’t prove expansion on their own, but they do show how surveillance is picking up activity in places that either had not reported animal outbreaks before or had not yet documented equine disease in the system. That’s an inference based on the reporting pattern, rather than a formal conclusion from EFSA. (efsa.europa.eu)
A broader regional perspective comes from the Viruses review on Latin America, which describes a mismatch between documented circulation in birds, horses, and mosquitoes and the relatively low number of confirmed human cases. Its argument is that underdiagnosis and surveillance gaps can obscure true risk. For veterinary readers, that’s a useful reminder that equine and animal data may reveal transmission even when the human burden appears limited, delayed, or incompletely measured. (mdpi.com)
Why it matters: For veterinarians, laboratories, and animal health officials, these papers collectively support a more operational role for equine medicine in zoonotic intelligence. Horses are highly relevant because they share mosquito exposure with people, can develop severe neurologic disease, and may help local authorities recognize viral circulation sooner. But the reviews also underline the trade-offs: equine surveillance works best where there is routine reporting, laboratory capacity, and clear pathways for data sharing across animal and human health sectors. In practical terms, this supports investment in seasonal preparedness, clinician awareness, serologic confirmation pathways, and coordination with public health partners rather than relying on passive case recognition alone. (mdpi.com)
What to watch: The next key test will be whether European systems keep moving toward earlier, more harmonized surveillance before the 2026 transmission season, especially as warm, wet conditions and longer mosquito seasons continue to be linked with higher West Nile risk. (who.int)