Comparative Usutu and West Nile virus transmission potential by local Culex pipiens mosquitoes in north-western Europe

摘要: Originating from Africa, Usutu virus (USUV) first emerged in Europe 2001. This mosquito-borne flavivirus caused high mortality rates its bird reservoirs, which strongly resembled the introduction of West Nile (WNV) 1999 United States. Mosquitoes infected with USUV incidentally transmit to other vertebrates, including humans, can result neuroinvasive disease. and WNV co-circulate parts southern Europe, but distribution extends into central northwestern Europe. In field, both viruses have been detected northern house mosquito Culex pipiens, potential for transmission is unknown. To understand dynamics assess spread USUV, we determined vector competence C. pipiens compared it well characterized WNV. We show time that European mosquitoes are highly effective vectors infection 11% at 18 °C 53% 23 °C, comparable values obtained Interestingly, a temperature 28 became more effectively (90%) than (58%), could be attributed barriers midgut. Small RNA deep sequencing showed strong bias 21-nucleotide small interfering (si)RNAs, map across entire viral genome on sense antisense strand. No evidence PIWI-associated (piRNA) was found, suggesting siRNA pathway major targets mosquitoes.