A paper published in Nature Climate Change by researchers at the University of Liverpool in the U.K. explores the risk of bluetongue transmission under future climates.
"There is concern that climate change will lead to expansion of vector-borne diseases as, of all disease types, they are the most sensitive to climate drivers. Such expansion may threaten human health and food security via effects on animal and crop health," the researchers said in the abstract to the article.
The study predicts that, by 2100, the disease risk will extend further north, the transmission season will last up to three months longer and outbreaks will be larger.
"A one in 20-year outbreak at present-day temperatures becomes typical by the 2070s under the highest greenhouse gas emission scenario," said study author Dr. Anne Jones from the University of Liverpool department of mathematical sciences.
However, the researchers said existing control measures, such as restricting animal movements, should still be sufficient to prevent the largest outbreaks, but they emphasized the need for an ongoing culture of vigilance.
"Bluetongue emerged in northern Europe in response to climate change and has already affected tens of thousands of farms at a huge financial cost and caused the deaths of millions of animals. Our results suggest that efficient detection and control measures to limit the spread of bluetongue and similar newly emerging vector-borne diseases will be increasingly vital in a future warmer world," Jones concluded.
According to the World Organization for Animal Health (OIE), bluetongue has a significant global distribution in regions where the insect vector (i.e., biting midges of the species Culicoides) is present, including Africa, Asia, Australia, Europe, North America and several islands in the tropics and subtropics. The virus is maintained in areas where the climate allows biting midges to survive over winter, OIE said.
There are more than 1,000 species of Culicoides, but fewer than 20 are considered competent vectors of the bluetongue virus, OIE said. The geographical distribution of the insect vector species, therefore, generally limits the distribution of the disease.