Why bird flu could threaten traditional Swiss cheeses 

Switzerland’s cows have dodged the global H5N1 bird flu so far. But if it hits dairy herds, the country’s iconic cheeses – from Raclette to Vacherin – could be at risk. Most traditional Swiss cheeses are made with unpasteurised milk. That makes them inherently riskier for consumers, especially for those with compromised immune systems, because they skip the pasteurisation process which kills harmful bacteria and viruses. Although the cheese industry and the Swiss government have, over the years, taken steps to minimise the health risks of consuming unpasteurised milk, also known as raw milk, a new threat is looming to this centuries-old production process. In March 2024, H5N1 – a strain of the highly pathogenic avian influenza (HPAI) virus deadly to birds and occasionally fatal in humans – was detected in dairy cattle in the US, marking the first known global cases in cows. While infected cattle typically develop only mild illness, the outbreak raised the alarm about the potential ...