Viruses That Affect Humans And Plants
West Nile virus is almost always spread to people by the bite of an infected mosquito. Mosquitoes become infected after feeding on birds that carry the virus. West Nile virus belongs to a family of viruses called Flaviviridae.
It is spread by mosquitoes that have fed on the blood of infected birds. West Nile virus is a member of the Japanese encephalitis virus complex of the genus Flavivirus , family Flaviviridae . This genus includes nine viruses distributed around the world.
West Nile encephalitis or meningitis has the potential to lead to brain damage and death. Approximately 10% of patients with brain inflammation do not survive.
Humans can be infected through the bite of an infected mosquito. Although WNv has not yet reached BC (see summary table below), it has been found within a few kilometers of our southern and eastern borders.
Human data is updated every Tuesday and Friday by 4pm. Dead bird and squirrel data are updated every Wednesday by 4pm. Humans are the only source for these viruses. These viruses do not multiply outside the human body.
Human-to-human transmission of Nipah virus has not been reported. Humans, horses, and some other mammals are highly susceptible to infection by the virus (7 ), and not all become too sick to travel during periods of potential viremia. Furthermore, it is unlikely that all animal hosts and vectors have been identified.
Infectious virus could not be recovered from the brains and organs of animals infected with gp50 or gp50+gp63 mutants, indicating that progeny virions produced in vivo are noninfectious.
Virions that lacked gp50 in their envelopes, and a phenotypically complemented pseudorabies virus gII mutant (which is unable to produce plaques in tissue culture cells), proved to be nonvirulent for mice. Infected trees can be bulldozed or cut with tree removal equipment. It is important to eradicate sucker shoots developing from tree stumps because they are known to be a good source of PPV.
Infected plants can serve as a source of inoculum for the rest of the field, so rogue (pull out and dispose of) symptomatic plants. Solanaceous plants such as tomatoes, peppers, nightshade and ground cherry can harbor the virus and serve as a source of inoculum.
Infected pea plants develop mosaic and chlorotic vein flecking (appears as translucent windows) and veinal enations (blisterlike outgrowths), which are very characteristic for PEMV (Plants are stunted, and proliferation of basal branches is common. Infection with the virus seems to be becoming more common in the United States, according to officials from the U.S.
This virus is different from other adenoviruses that cause the common cold in that it may produce an unusually severe illness requiring intensive medical care.
Viruses also carry genes for making proteins that are never incorporated into the virus particle and are found only in infected cells. These viral proteins are called nonstructural proteins; they include factors required for the replication of the viral genome and the production of the virus particle.
Viruses are strange things that straddle the fence between living and non-living. On the one hand, if they’re floating around in the air or sitting on a doorknob, they’re inert. Viruses are sometimes confused with computer worms and Trojan horses . A worm can spread itself to other computers without needing to be transferred as part of a host, and a Trojan horse is a file that appears harmless.