The Death of a Blackbird highlights the looming danger of the West Nile virus in the UK

The deadly virus is killing Blackbirds all over the UK. Beyond the risks for birds, its spread indicates that mosquito-borne viruses are currently pose a threat to humans and animals in the country as a result of climate change.

The virus in question, USUTU, occurred in South Africa in 1959, but is now spreading in Europe. It caused fatal diseases in certain birds, especially black swans, and was first detected in the UK in 2020. In some parts of the country, the Blackbird population, the most notable London, has fallen by more than 40% since 2018. “I first noticed a decline when USUTU popped up,” he says. Hugh Hammer With British trust for ornithology.

Though catastrophic to bird life, USUTU poses low risks to humans and mammals. Human infectious diseases are rare and generally cause mild fever, but the arrival of the virus in the UK marked the first time by mosquito-borne viral zoonotic diseases (a disease that can be transmitted from animals to humans) that have appeared in domestic animal hosts. Virus experts are closely monitoring how well and fast the disease is spreading, as it could be a template for the future spread of other mosquito-borne diseases.

For example, the West Nile virus spreads just like USUTU and requires the same environmental conditions. “The same mosquitoes that can send USUTUs can usually send West Nile. [for Usutu] It can also serve as a host for West Nile.” Alanfolly at the British Animal and Plant Health Organization (APHA).

Humans can also contract the West Nile virus when bitten by mosquitoes, but the symptoms can be more severe than those of USUTU. Approximately 20% of infected people experience symptoms including fever, headache, body pain, vomiting and diarrhea. In rare cases, this virus can cause serious inflammation of the brain and spinal cord, which is fatal. There are no known human vaccines.

Climate change has helped accelerate the spreading of the West Nile virus through Northern and Eastern Europe. Research Showas the virus thrives in warm summer temperatures. In the Netherlands, USUTU was first detected in 2016, and the West Nile virus continued in 2020. British officials fear a similar pattern will unfold in their country. Demonstrating research The climate there is becoming more and more kind to mosquito-borne viruses. “The idea is if there's usutu here, West Nile is likely to come at some point and last, given the right conditions,” Folly says.

In response to the threat, APHA launched a project in 2023 to track the emergence and transmission routes of USUTU and other mosquito-borne viruses in wild birds. Infrastructure to track this virus It is essential for the country to respond quickly to West Nile's arrival, Foley says. “Our real goal, or willingness from a government perspective, is to be able to detect these. [new viruses] We circulate animal populations before they can be transmitted to humans. ”

Reina Sikkema The University of Erasmus Medical Center in Rotterdam is studying the emergence of the Netherlands Ustus and the West Nile virus. The West Nile has not been detected since 2022,He believes the virus is circulating at low levels and is now being controlled by a relatively cool climate. “I believe it exists, but it takes the right situation to burn,” she says. Sikkema said detection of the West Nile in the UK is now inevitable, but he believes similar climatic factors can prevent the virus from spreading too widely.

However, the temperature rise in summer including Increased frequency of tropical nights – The UK's Met Office Weather Agency defines Sikkema that if the minimum temperature is not below 20°C, it could change photos of the UK, the Netherlands and other Northern European countries. “Mosquito-borne is not [just] On your Spanish holiday, or when you go to South America,” says Folly.

Like the potential risk of the West Nile virus to people, Folly says we shouldDon't forget what USUTU is doing to Blackbirds in the UK: “If 40% of humans die in Greater London, you'll know about it very quickly.”