UK mosquito species may carry avian malaria, new study finds

A mosquito lands on a blackbird's wing. It pierces the skin, draws blood, and moves on. Somewhere in that moment, a parasite called Plasmodium slips into the bird's bloodstream. Researchers have long known this happens across the UK, but they weren’t sure which mosquitoes do the transmitting. They finally have answers to that puzzle.A two-year study from Keele University found how avian malaria moves through Britain's wild bird populations, and the real culprits behind it. The researchers found that multiple mosquito species in the UK have the potential to carry diseases such as avian malaria and pose a threat to wildlife. These findings were published in the journal Parasitology.Some species of mosquitoes pose a threat to wild birdsMosquitoes are the primary vectors for several fatal and debilitating diseases. They transmit viruses and parasites to humans and animals through their saliva when biting. These tiny insects are known for transmitting diseases such as malaria and dengue fever to humans; however, less was known about how they transmit disease to wild birds.A team led by Dr Jenny Dunn collected more than 1,000 insects over the two years, narrowing the sample to 12 distinct mosquito species. They examined the salivary glands, where parasites accumulate before spreading to new hosts through bites. Nine of the species tested positive for bird malaria traces. This suggested their involvement in disease circulation that had never been clearly documented before. Genetic analysis revealed several different types, or ‘lineages’, of these parasites.The parasite in question, Plasmodium, does not pose a threat to human health, but it can weaken infected birds, making them vulnerable to predation, starvation, and other challenges. In the UK's fragile ecosystems, that matters."We know that avian malaria and other blood parasites are common in UK birds, but this is the first study to look in more depth at which species of mosquito might transmit them. Avian malaria can have negative impacts on the birds it infects, so it is important to understand how it is transmitted and which mosquito species might be responsible," Dunn saidThis study is the first to identify mosquito species that are capable of spreading specific bird malaria parasites in the UK. Ochlerotatus detritus mosquitoes, for instance, appear to be the carriers most likely to transmit Plasmodium vaughani, a lineage commonly found in UK blackbirds. Two other species, Ochlerotatus annulipes and Anopheles messeae, are also potential vectors for different parasite strains circulating among robins, goldfinches, whitethroats, and other species.Understanding these transmission pathways opens doors for conservation work. These findings could now drive habitat management and population monitoring efforts in the future.