Swedish mosquitoes can carry Japanese encephalitis virus, raising European disease risk
Researchers found that common Swedish mosquitoes can be infected with Japanese encephalitis virus, a serious pathogen spreading across Asia. The discovery suggests Europe's warming climate could eventually enable the disease to establish itself on the continent, prompting insurers, public health agencies, and medical device makers to prepare for potential outbreaks.
Originaltitel: Vector competence of Swedish <em>Culex pipiens</em> mosquitos for Japanese encephalitis virus
<p>Background</p><p>Japanese encephalitis virus (JEV) is an emerging mosquito-borne Orthoflavivirus that poses a significant public health risk in many temperate and tropical regions in Asia. Since the climate in some endemic countries is similar to temperate climates observed in Europe, understanding the role of specific mosquito species in the transmission of JEV is essential for predicting and effectively controlling the potential for the introduction and establishment of JEV in Europe.</p><p>Methods</p><p>This study aimed to investigate the vector competence of colonized Culex pipiens biotype molestus mosquitoes for JEV. The mosquitoes were initially collected from the field in southern Sweden. The mosquitoes were offered a blood meal containing the Nakayama strain of JEV (genotype III), and infection rates, dissemination rates, and transmission rates were evaluated at 14, 21, and 28 days post-feeding.</p><p>Results</p><p>The study revealed that colonized Swedish Cx. pipiens are susceptible to JEV infection, with a stable infection rate of around 10% at all timepoints. However, the virus was only detected in the legs of one mosquito at 21 days post-feeding, and no mosquito saliva contained JEV.</p><p>Conclusions</p><p>Overall, this research shows that Swedish Cx. pipiens can become infected with JEV, and emphasizes the importance of further understanding of the thresholds and barriers for JEV dissemination in mosquitoes.</p>