West Nile Virus
Understanding West Nile Virus Transmission Methods
The dangerously infectious West Nile virus (WNV) is kept alive in a continuous cycle of mosquito-to-bird contacts and mosquito to offspring transference. A mosquito ingests the virus by feeding on the blood of a contaminated bird or an infected female mosquito transfers the virus to its eggs. Typical scientific findings regarding the West Nile virus transmission have determined that female mosquitoes, once infected, can pass on the illness in the following manners:
About Horizontal Transmission
Although horizontal transmission is of significant importance to sustaining the virus in nature during the year’s warm summer months and into the fall, a further process is required to preserve its existence during the cold winter months when mosquitoes become inactive. This other method of transmission is known as vertical.
About Vertical Transmission
Field and Facility Testing
Reports from research conducted in nature have concluded that infected female mosquitos of the “Culex pipiens” genus can in fact vertically transmit the West Nile virus to its descendants, permitting the strain to remain effective while withstanding the northern winter climate. The virus quarantine has been collected from both adult males and nulliparous females (those who have not yet spawned) in the field over the summer. The same virus was also drawn from female mosquitoes resting in standing water the following winter. End results have indicated that vertical transmission is likely happening by course of nature.
Indoor lab studies have gone on to further prove the argument by manually injecting adult female mosquitoes with WNV. After a week of incubation, they were released for the next phase of testing. The procedure has essentially shown evidence of same: that even after a controlled period of hibernation, the vertically transmitted newborns of the contaminated female were still capable of infecting small test subjects with the West Nile virus.
The Culexbreed of mosquito (a.k.a. the common North American mosquito) is considered the primary carrier of the West Nile virus strain, and responsible for the widespread of the ever-present, potentially harmful disease.