Scientists have determined that mosquitoes are not responsible for transmitting Lyme disease, identifying ticks as the sole carriers of the illness. This conclusion comes after ongoing speculation about whether other insects, particularly mosquitoes, could be involved in spreading Lyme disease due to patients often not recalling tick bites before symptoms appear.
The study, published in Parasites and Vectors, involved an international team of researchers including Fernando Noriega from Florida International University (FIU). The research found that the bacteria causing Lyme disease is rarely present in high concentrations in the bloodstream. Because mosquitoes feed quickly, they do not ingest enough bacteria to become infected or transmit it. In contrast, ticks feed slowly and can acquire the bacteria as it moves from tissues into their system.
“Our results show that mosquitoes do not have the biological capacity to efficiently acquire and maintain the bacteria that cause Lyme disease, and that they are unable to transmit them naturally or mechanically,” said Noriega, emeritus professor of biology and researcher at FIU’s Biological Sciences Institute. “This study provides compelling evidence against Lyme disease transmission by mosquitoes and reinforces Ixodes ticks as the only competent vectors, which is critical for targeted public health interventions and accurate risk communication.”
The researchers also discovered that mosquitoes possess an enzyme in their digestive system capable of destroying the bacteria responsible for Lyme disease. As a result, even if a mosquito were to bite an infected animal, any bacteria ingested would be eliminated during digestion.
Matthew DeGennaro, director of FIU’s Biomolecular Sciences Institute and a neurogeneticist specializing in mosquito behavior, emphasized: “The need for scientific investigation and eliminating suspects is key in tackling vector-borne diseases.” The institute continues its work on treatments and prevention methods for diseases transmitted by various vectors such as mosquitoes and ticks.
The research was led by Miriama Pekľanská under Marcela Nouzova’s direction. Nouzova previously served as a research professor at FIU and now leads the Laboratory of Physiology and Molecular Biology of Mosquitoes at the Institute of Parasitology at the University of South Bohemia in the Czech Republic.
