Detection of West Nile virus lineage 2 in mosquitoes during a human outbreak in Greece

Abstract

A human outbreak of West Nile virus (WNV) infections occurred in 2010 in central Macedonia, northern Greece. Most cases were observed close to four rivers forming a large Delta, a major Mediterranean wetland. WNV lineage 2 sequences were obtained from two pools of Culex pipiens mosquitoes trapped in sites where encephalitis cases occurred a few days before the trapping. The Greek strain showed the highest homology to Hungarian and South African strains, differing from the Russian WNV lineage 2 strain, which suggests that at least two lineage 2 strains have been introduced and established in Europe, causing severe disease to humans.

Recent progress in West Nile virus diagnosis and vaccination

“…Since 2004 lineage 2 has also been observed in central [41] and Eastern [42] Europe. In 2010 it caused outbreaks in Romania [43] and Greece [44] and in 2011 it was detected for the first time in Italy [45]. The Greek and Italian strains showed the highest homology to Hungarian and South African strains, differing from the Russian lineage 2 strains.…”

The Essential, Nonredundant Roles of RIG-I and MDA5 in Detecting and Controlling West Nile Virus Infection

“…Since its emergence into North America in 1999, there have been over 36,000 cases of human WNV infection in the United States, including the second highest annual peak of over 5,000 cases in 2012 alone (2,3). Moreover, there remains a potential for newly emerging pathogenic WNV strains to cause additional and possibly increasingly severe human outbreaks (4,5). Infection with WNV is characterized by an acute febrile episode that can progress to neuroinvasive disease, including encephalitis, meningitis, and flaccid paralysis.…”

Usutuvirus

“…B. nach Impfung gegen Gelbfieber, Japanische Enzephalitis oder FSME oder aber nach Infektionen mit anderen Flaviviren wie DENV, FSMEV, JEV oder SLEV, die bei Aufenthalten in den entsprechenden Endemiegebieten erworben wurden. Für den Nachweis von Antikörpern gegen WNV wurde gezeigt, dass Kreuzreaktionen auftreten können, die aber in der Regel durch den Nachweis von erregerspezifischen neutralisierenden Antikörpern im PRNT abgeklärt werden können [57,58,59].…”