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West Nile virus

Virus classification
Group: Group IV ((+)ssRNA)
Family: Flaviviridae
Genus: Flavivirus
Species: West Nile virus
West Nile Fever
Classification and external resources
ICD-10 A92.3
DiseasesDB 30025
MeSH D014901

West Nile virus (or WNV) is a virus of the family Flaviviridae; part of the Japanese encephalitis (JE) antigenic complex of viruses, it is found in both tropical and temperate regions. Virus classification involves naming and placing Viruses into a taxonomic system An RNA virus is a Virus that has RNA (ribonucleic acid as its Genetic material. The Flaviviridae are a family of Viruses that are primarily spread through arthropod vectors (mainly ticks and mosquitoes Flavivirus is a genus of the family Flaviviridae. This genus includes the West Nile virus, Dengue virus The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify Diseases The International Statistical Classification of Diseases and Related Health Problems 10th Revision ( ICD -10) is a coding of diseases and signs symptoms abnormal findings A00-A79 - Bacterial infections and other intestinal infectious diseases and STDs (A00-A09 Intestinal Infectious diseases ( The Diseases Database is a free Website that provides information about the relationships between medical conditions Symptoms, and Medications. Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable The Flaviviridae are a family of Viruses that are primarily spread through arthropod vectors (mainly ticks and mosquitoes The Tropics are centered on the Equator and limited in Latitude by the Tropic of Cancer in the northern hemisphere at approximately 23°26' (23 It mainly infects birds, but is known to infect humans, horses, dogs, cats, bats, chipmunks, skunks, squirrels, and domestic rabbits. Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Human beings, humans or man (Origin 1590–1600 L homō man OL hemō the earthly one (see Humus The horse ( Equus caballus) is a hoofed ( Ungulate) Mammal, one of eight living species of the family Equidae. The dog ( Canis lupus familiaris) is a domesticated Subspecies of the gray wolf, a Mammal of the Canidae family of the order WikipediaManual of Style (spelling, articles should conform to one overall spelling style of English typically the one most linked to the article topic (if it is geographic Chipmunk is the common name for any small Squirrel -like Rodent species of the genus Tamias in the family Sciuridae. Skunks (sometimes referred to as polecats) are Mammals best known for their ability to excrete a strong foul-smelling odor. A squirrel is one of the many small or medium-sized Rodents in the family Sciuridae. Rabbits are small Mammals in the family Leporidae of the order Lagomorpha, found in several parts of the world The main route of human infection is through the bite of an infected mosquito. An infection is the detrimental Colonization of a host Organism by a foreign Species. Mosquitoes are insects in the family Culicidae. They have a pair of scaled wings a pair of Halteres, a slender body and long legs

Image reconstructions and cryoelectron microscopy reveal a 45-50 nm virion covered with a relatively smooth protein surface. Electron cryomicroscopy ( cryo-EM or sometimes cryo-electron microscopy) is a form of Electron microscopy (EM where the sample is studied at Cryogenic Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl This structure is similar to the dengue fever virus; both belong to the genus Flavivirus within the family Flaviviridae. The genetic material of WNV is a positive-sense, single strand of RNA, which is between 11,000 and 12,000 nucleotides long; these genes encode seven non-structural proteins and three structural proteins. The RNA strand is held within a nucleocapsid formed from 12 kDa protein blocks; the capsid is contained within a host-derived membrane altered by two viral glycoproteins. The unified atomic mass unit ( u) or Dalton ( Da) or sometimes universal mass unit, is an unit of Mass used to express

Contents

Symptoms

Electron micrograph of West Nile virus.
Electron micrograph of West Nile virus.

W. N. V. has three different effects on humans. The first is an asymptomatic infection; the second is a mild febrile syndrome termed West Nile Fever;[1] the third is a neuroinvasive disease termed West Nile meningitis or encephalitis. Fever (also known as pyrexia, from the Greek pyretos meaning fire or a febrile response, from the Latin word Febris Meningitis is Inflammation of the protective membranes covering the Brain and Spinal cord, known collectively as the Meninges. Encephalitis is an acute Inflammation of the Brain, commonly caused by a viral Infection. [2] In infected individuals the ratio between the three states is roughly 110:30:1. [3]

The second, febrile stage has an incubation period of 3-8 days followed by fever, headache, chills, diaphoresis, weakness, lymphadenopathy, and drowsiness. Diaphoresis is excessive sweating commonly associated with shock and other Medical emergency conditions Lymphadenopathy is a term meaning "disease of the Lymph nodes. Occasionally there is a short-lived truncal rash and some patients experience gastrointestinal symptoms including nausea, vomiting, loss of appetite, or diarrhea. All symptoms are resolved within 7-10 days, although fatigue can last for some weeks and lymphadenopathy can take up to two months to resolve.

The more dangerous encephalitis is characterized by similar early symptoms but also a decreased level of consciousness, sometimes approaching near-coma. Deep tendon reflexes are hyperactive at first, later diminished. There are also extrapyramidal disorders. Movement disorders include Akathisia Akinesia ( lack of movement) Athetosis ( contorted torsion Recovery is marked by a long convalescence with fatigue.

More recent outbreaks have resulted in a deeper study of the disease and other, rarer, outcomes have been identified. The spinal cord may be infected, marked by anterior myelitis with or without encephalitis. [4] WNV-associated Guillain-Barré syndrome has been identified[5] and other rare effects include multifocal chorioretinitis (which has 100% specificity for identifying WNV infection in patients with possible WNV encephalitis)[6] hepatitis, myocarditis, nephritis, pancreatitis, and splenomegaly. Guillain-Barré syndrome ( GBS) (in French ɡilɛ̃ baˈʁe in English ˈɡiːlæn ˈbɑreɪ /ɡiːˈæn bəˈreɪ/ etc Chorioretinitis is an inflammation of the Choroid and Retina of the eye Hepatitis (plural hepatitides) implies injury to the Liver characterized by the presence of Inflammatory cells in the tissue of In Medicine ( Cardiology) myocarditis is Inflammation of the Myocardium, the muscular part of the Heart. Nephritis is Inflammation of the Kidney. The word comes from the Greek nephro- meaning "of the kidney" and -itis meaning "inflammation" Pancreatitis is the Inflammation of the Pancreas. See also Acute pancreatitis and Chronic pancreatitis for more details Splenomegaly is an enlargement of the Spleen, which usually lies in the left upper quadrant (LUQ of the Human abdomen. [7][8][9]

Transmission and susceptibility

Transmission

The proboscis of an Aedes albopictus mosquito feeding on human blood. Under experimental conditions, the Aedes albopictus mosquito (also known as the Asian Tiger Mosquito) has been found to be a vector of West Nile Virus.
The proboscis of an Aedes albopictus mosquito feeding on human blood. The Asian tiger mosquito or forest day mosquito ( Aedes albopictus) from the Mosquito family Culicidae, is characterized by its Mosquitoes are insects in the family Culicidae. They have a pair of scaled wings a pair of Halteres, a slender body and long legs Under experimental conditions, the Aedes albopictus mosquito (also known as the Asian Tiger Mosquito) has been found to be a vector of West Nile Virus.

The virus is transmitted through mosquito vectors, which bite and infect birds. In Epidemiology, a vector is an Organism that does not cause Disease itself but which transmits Infection by conveying Pathogens from The birds are amplifying hosts, developing sufficient viral levels to transmit the infection to other biting mosquitoes which go on to infect other birds (in the Western hemisphere the American robin and the American crow are the most common carriers) and also humans. The Western Hemisphere, also Western hemisphere or western hemisphere, is a geographical term for the half of the Earth that lies West The American Robin, Turdus migratorius, is a migratory Songbird of the thrush family The American Crow, Corvus brachyrhynchos, is a large Passerine bird Species of the family Corvidae. The infected mosquito species vary according to geographical area; in the US Culex pipiens (Eastern US), Culex tarsalis (Midwest and West), and Culex quinquefasciatus (Southeast) are the main sources. [10]

In mammals the virus does not multiply as readily (i. e. does not develop high viremia during infection), and it is believed that mosquitoes biting infected mammals do not ingest sufficient virus to become infected,[11] making mammals so-called dead-end infections. Viremia (UK viraemia) is a medical condition where Viruses enter the Bloodstream and hence have access to the rest of the body

A 2004 paper in Science found that Culex pipiens mosquitoes existed in two populations in Europe, one which bites birds and one which bites humans. In North America 40% of Culex pipiens were found to be hybrids of the two types which bite both birds and humans, providing a vector for West Nile virus. This is thought to provide an explanation of why the West Nile disease has spread more quickly in North America than Europe.

Susceptibility

It was initially believed that direct human-to-human transmission was only caused by occupational exposure,[12] or conjunctival exposure to infected blood. [13] The US outbreak revealed novel transmission methods, through blood transfusion,[14] organ transplant,[15] intrauterine exposure,[16] and breast feeding. [17] Since 2003 blood banks in the US routinely screen for the virus amongst their donors. [18] As a precautionary measure, the UK's National Blood Service runs a test for this disease in donors who donate within 28 days of a visit to the United States or Canada. The National Blood Service is the organisation for England and North Wales which collects Blood and other tissues tests processes and supplies all the Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page

The more severe outcomes of WNV infection are clearly associated with advancing age[19] and a patient history of organ transplantation[20] and diabetes. A genetic factor also appears to increase susceptibility to West Nile disease. A mutation of the gene CCR5 gives some protection against HIV but leads to more serious complications of WNV infection. Human immunodeficiency virus ( HIV) is a Lentivirus (a member of the Retrovirus family that can lead to acquired immunodeficiency syndrome Carriers of two mutated copies of CCR5 made up 4 to 4. 5% of a sample of West Nile disease sufferers while the incidence of the gene in the general population is only 1%. [21][22]

Recently, the potential for mosquito saliva to impact the course of WNV disease was demonstrated. Mosquitoes are insects in the family Culicidae. They have a pair of scaled wings a pair of Halteres, a slender body and long legs [23][24][25] Mosquitoes inoculate their saliva into the skin while obtaining blood. Mosquito saliva is a pharmacologic cocktail of secreted molecules, principally proteins, that can affect vascular constriction, blood coagulation, platelet aggregation, inflammation, and immunity. Coagulation is a complex process by which Blood forms Clots It is an important part of Hemostasis (the cessation of blood loss from a damaged vessel whereby Platelets, or Thrombocytes, are small cytoplasmic bodies derived from cells They circulate in the Blood of Mammals and are involved Inflammation ( Latin, inflamatio, to set on fire is the complex biological response of vascular tissues to harmful stimuli such as Pathogens It has become clear that mosquito saliva alters the immune response in a manner that may be advantageous to a virus. An immune system is a collection of mechanisms within an Organism that protects against Disease by identifying and killing Pathogens and Tumor [26][27][28][29] Studies have shown that it can specifically modulate the immune response during early virus infection,[30] and mosquito feeding can exacerbate WNV infection leading to higher viremia and more severe forms of disease. Viremia (UK viraemia) is a medical condition where Viruses enter the Bloodstream and hence have access to the rest of the body [23][24][25] It is unknown what benefit, if any, the mosquito receives by assisting the virus in this manner, so it is likely that the virus is simply capitalizing on preexisting qualities of mosquito saliva developed for other purposes.

There is no vaccine for humans. A vaccine is a biological preparation which is used to establish or improve immunity to a particular disease A vaccine for horses based on killed viruses exists; some zoos have given this vaccine to their birds, although its effectiveness there is unknown. A zoological garden, shortened to zoo, is an institution in which living animals are exhibited in captivity Dogs and cats show few if any signs of infection. There have been no cases of direct canine-human or feline-human transmission; although these pets can become infected, it is unlikely that they are in turn capable of infecting native mosquitoes and thusly continuing the disease cycle. [31]

Avoiding mosquito bites is the most straightforward means to avoid infection[32] - remaining indoors (while preventing mosquitoes from entering) at dawn and dusk, wear light-colored clothing that covers arms and legs as well as trunk, use insect repellents on both skin and clothing (such as DEET, picaradin, or oil of lemon eucalyptus for skin and permethrin for clothes). N, N -Diethyl- meta -toluamide, abbreviated DEET, is the most common active Ingredient in Insect repellents It is intended Icaridin, also known as picaridine, KBR 3023, under the INCI name hydroxyethyl isobutyl piperidine carboxylate, and under the old trade Corymbia citriodora is a tall Tree, to 50 metres in height from Temperate and tropical eastern Australia. Permethrin is a common synthetic chemical widely used as an Insecticide and Acaricide and as an Insect repellent. [33] If one becomes infected, generally, treatment is purely supportive: analgesia for the pain of neurologic diseases; rehydration for nausea, vomiting, or diarrhea; encephalitis may also require airway protection and seizure management.

Reported cases in the U. S. in 2005 exceeded those in 2004 and cases in 2006 exceeded 2005's totals. On August 19, 2006, the LA Times reported that the expected incidence rate of West Nile was dropping as the local population becomes exposed to the virus. Events 43 BC - Octavian, later known as Augustus compels the Roman Senate to elect him Consul. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. The Los Angeles Times (also known as the LA Times) is a daily Newspaper published in Los Angeles California and distributed "In countries like Egypt and Uganda, where West Nile was first detected, people became fully immune to the virus by the time they reached adulthood", federal health officials said. [34] However, just days later, the CDC said that West Nile cases could reach a 3-year high because hot temperatures had allowed a larger brood of mosquitoes. [35]

History

Studies of phylogenetic lineages have determined that WNV emerged as a distinct virus around 1000 years ago. [36] This initial virus developed into two distinct lineages, Lineage 1 and its multiple profiles is the source of the epidemic transmission in Africa and throughout the world, while Lineage 2 remains as an Africa zoonose. A zoonosis (ˌzoʊəˈnoʊsɨs or zoonose is any Infectious disease that is able to be transmitted (by a vector) from other Animals both wild and domestic

WNV was first isolated from a feverish adult woman in the West Nile District of Uganda in 1937 during research on yellow fever. West Nile sub-region (previously known as West Nile Province and West Nile District) is a region in north-western Uganda that consists of the districts The Republic of Uganda is a Landlocked country in East Africa. Yellow fever (also called yellow jack, black vomit or sometimes American Plague) is an acute viral disease A series of serosurveys in 1939 in central Africa found anti-WNV positive results ranging from 1. 4% (Congo) to 46. 4% (White Nile region, Sudan). It was subsequently identified in Egypt (1942) and India (1953), a 1950 serosurvey in Egypt found 90% of those over 40 years in age had WNV antibodies. This article is about the country of Egypt For a topic outline on this subject see List of basic Egypt topics. India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country The ecology was characterized in 1953 with studies in Egypt[37] and Israel. This article is about the country of Egypt For a topic outline on this subject see List of basic Egypt topics. For a topic outline on this subject see List of basic Israel topics. [38] The virus became recognized as a cause of severe human meningoencephalitis in elderly patients during an outbreak in Israel in 1957. Meningoencephalitis (ˌmɛnɪnˈgo ɛnˌsɛfəˈlaɪtɪs from Greek: meninges- membranes enkephalos brain and -itis inflammation is The disease was first noted in horses in Egypt and France in the early 1960s and found to be widespread in southern Europe, southwest Asia and Australia. This article is about the country For a topic outline on this subject see List of basic France topics. Surprisingly the first strain of what is thought to be West Nile can be traced all the way back to the 1600s.

The first appearance of West Nile virus in the Western hemisphere was in 1999 with encephalitis reported in humans and horses, and the subsequent spread in the United States may be an important milestone in the evolving history of this virus. The United States of America —commonly referred to as the The American outbreak began in the New York City area, including New Jersey and Connecticut, and the virus is believed to have entered in an infected bird or mosquito, although there is no clear evidence. The City of New York New Jersey ( is a state in the Mid-Atlantic and Northeastern regions of the United States. Connecticut ( is a state located in the New England region of the northeastern United States of America. [39] The US virus was very closely related to a lineage 1 strain found in Israel in 1998. Since the first North American cases in 1999, the virus has been reported throughout the United States, Canada, Mexico, the Caribbean and Central America. There have been human cases and horse cases, and many birds are infected. Both the US and Israeli strains are marked by high mortality rates in infected avian populations, the presence of dead birds - especially corvidae - can be an early indicator of the arrival of the virus. Corvidae is a cosmopolitan family of Oscine Passerine Birds that contains the Crows Ravens rooks

A high level of media coverage through 2001/2002 raised public awareness of West Nile virus. Media circus describes a News event where the media coverage is perceived to be out of proportion to the event being covered such as the number of Reporters at the This coverage was most likely the result of successive appearances of the virus in new areas, and had the unintended effect of increasing funding for research on this virus and related arthropod-borne viruses. Arthropods are Animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, " Joint " Such research has expanded our understanding of viruses transmitted by mosquitoes.

Overwintering mechanism

Vertical transmission of West Nile Virus from female Culex pipiens mosquitoes to their progeny has been demonstrated in the laboratory. Vertical transmission, also known as Mother-to-child transmission refers to transmission of an Infection, such as HIV, Hepatitis B, or Hepatitis It has been suggested that vertically infected Culex could survive the winter to initiate a WNV amplification cycle the following spring. Culex mosquitoes spend the winter hibernating in protected structures such as root cellars, bank barns, caves, abandoned tunnels and other subterranean locations. The first overwintering adult mosquitoes to test positive for WNV were collected in New York, 2000. Since then, positive samples have been identified in New Jersey, 2003 and in Pennsylvania, 2003, 2004 and 2005. [40]

Geographic distribution

West Nile virus has been described in Africa, Europe, the Middle East, west and central Asia, Oceania (subtype Kunjin), and most recently, North America. The Middle East is a Subcontinent with no clear boundaries often used as a synonym to Near East, in opposition to Far East.

Recent outbreaks of West Nile virus encephalitis in humans have occurred in Algeria (1994), Romania (1996 to 1997), the Czech Republic (1997), Congo (1998), Russia (1999), the United States (1999 to 2003), Canada (1999–2003), and Israel (2000). Algeria ( ar [[Arabic]] الجزائر, Al Jaza'ir ælʤæˈzæːʔir Amazigh: ⴷⵥⴰⵢⴻⵔ Dzayer) officially the People's Year 1994 ( MCMXCIV) was a Common year starting on Saturday (link will display full 1994 Gregorian calendar) Romania ( dated: Rumania, Roumania Year 1996 ( MCMXCVI) was a Leap year starting on Monday (link will display full 1996 Gregorian calendar) The Czech Republic ( ˈt͡ʃɛskaː ˈrɛpuˌblɪka short form in Česko ˈt͡ʃɛskɔ also called Czechia, The Democratic Republic of the Congo (République démocratique du Congo often referred to as DR Congo, DRC or RDC, and formerly known or referred to Year 1998 ( MCMXCVIII) was a Common year starting on Thursday (link will display full 1998 Gregorian calendar) Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending For a topic outline on this subject see List of basic Israel topics. 2000 ( MM) was a Leap year that started on Saturday of the Common Era, in accordance with the Gregorian calendar.

Epizootics of disease in horses occurred in Morocco (1996), Italy (1998), the United States (1999 to 2001), and France (2000). Morocco (المغرب "al-Maghrib" officially the Kingdom of Morocco (المملكة المغربية is a country located in North Africa Italy (Italia officially the Italian Republic, (Repubblica Italiana is located on the Italian Peninsula in Southern Europe, and on the two largest This article is about the country For a topic outline on this subject see List of basic France topics. In 2003, West Nile virus spread among horses in Mexico.

In the US in 2002, West Nile virus was documented in animals in 44 states and the District of Columbia with Illinois, Louisiana, Michigan, and Ohio reporting the most deaths. Washington DC ( formally the District of Columbia and commonly referred to as Washington, the District, or simply D The State of Illinois ( roughly ill-i-NOY is a state of the United States of America, the 21st to be admitted to the Union. The State of Louisiana ( or, État de Louisiane, pronounced) is a state located in the southern region of the United States of America Michigan ( is a Midwestern state of the United States of America. Ohio ( is a Midwestern state of the United States. As part of the Great Lakes region, Ohio has long been a cultural and geographical crossroads By 2003, 45 states and D. C. had reported human cases.

Recent outbreaks

United States: From 1999 through 2001, the CDC confirmed 149 West Nile virus infections, including 18 deaths. The Centers for Disease Control and Prevention (or CDC) is an agency of the United States Department of Health and Human Services based in unincorporated In 2002, a total of 4,156 cases were reported, including 284 fatalities. 13 cases in 2002 were contracted through blood transfusion. The cost of West Nile-related health care in 2002 was estimated at $200 million. The first human West Nile disease in 2003 occurred in June and one West Nile-infected blood transfusion was also identified that month. In the 2003 outbreak, 9,862 cases and 264 deaths were reported by the CDC. At least 30% of those cases were considered severe involving meningitis or encephalitis. In 2004, there were only 2,539 reported cases and 100 deaths. In 2005, there was a slight increase in the number of cases, with 3,000 cases and 119 deaths reported. 2006 saw another increase, with 4,269 cases and 177 deaths. In 2007, the number of cases reported decreased to 3,623 and the number of deaths dropped to 124.

West Nile Virus Cases in the United States
West Nile Virus Cases in the United States

See also Progress of the West Nile virus in the United States

Canada: One human death occurred in 1999. The West Nile virus quickly spread across North America after its introduction in 1999 In 2002, ten human deaths out of 416 confirmed and probable cases were reported by Canadian health officials. In 2003, 14 deaths and 1,494 confirmed and probable cases were reported. Cases were reported in 2003 in Nova Scotia, Quebec, Ontario, Manitoba, Saskatchewan, Alberta, British Columbia, and the Yukon. Nova Scotia (ˌnəʊvəˈskəʊʃə ( Latin for New Scotland; Alba Nuadh Nouvelle-Écosse is a Canadian province located on Canada 's Quebec (kwɨˈbɛk Ontario (ɒnˈtɛrioʊ is a province located in the central part of Canada, the largest by population and second largest after Quebec Manitoba (English ˌmænɨˈtoʊbə French /manitoba/ is a province of Canada, spanning 647797 square kilometres (250116  sq mi of North America Saskatchewan (səˈskætʃəwən) is a prairie province in Canada, which has an area of 588276 Alberta (ælˈbɝtə is one of Canada's prairie provinces. It became a province on September 1 1905 British Columbia (ˌbrɪtɨʃ kəˈlʌmbiə ( BC) ( (la Colombie-Britannique C Yukon (ˈjuːkɒn is the westernmost and smallest of Canada's three territories. In 2004, only 26 cases were reported and two deaths; however, 2005 saw 239 cases and 12 deaths. By October 28, 2006, 127 cases and no deaths had been reported. Events 306 - Maxentius is proclaimed Roman Emperor. 312 - Battle of Milvian Bridge: Constantine Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. One case was asymptomatic and only discovered through a blood donation. Currently in 2007, 445 Manitobans have confirmed cases of West Nile and two people have died with a third unconfirmed but suspected. [41] 17 people have either tested positive or are suspected of having the virus in Saskatchewan, and only one person has tested positive in Alberta. [42] Saskatchewan has reported 826 cases of West Nile plus three deaths. Saskatchewan (səˈskætʃəwən) is a prairie province in Canada, which has an area of 588276 [43]

Israel: In 2000, the CDC found that there were 417 confirmed cases with 326 hospitalizations. The Centers for Disease Control and Prevention (or CDC) is an agency of the United States Department of Health and Human Services based in unincorporated 33 of these people died. The main clinical presentations were encephalitis (57. 9%), febrile disease (24. 4%), and meningitis (15. 9%). [44]

Romania: In 1996-1997 about 500 cases occurred in Romania with a fatality rate of nearly 10%.

Surveillance methods

West Nile virus can be sampled from the environment by the pooling of trapped mosquitoes, testing avian blood samples drawn from wild birds and dogs and sentinel monkeys, as well as testing brains of dead birds found by various animal control agencies and the public. Testing of the mosquito samples requires the use of RT-PCR to directly amplify and show the presence of virus in the submitted samples. In Molecular biology, reverse transcription polymerase chain reaction (RT-PCR is a Laboratory technique for amplifying a defined piece of a Ribonucleic When using the blood sera of wild bird and sentinel chickens, samples must be tested for the presence of West Nile virus antibodies by use of immunohistochemistry (IHC)[45] or Enzyme-Linked Immunosorbent Assay (ELISA). Antibodies (also known as immunoglobulins, abbreviated Ig) are Gamma globulin Proteins that are found in Blood or other Bodily Immunohistochemistry or IHC refers to the process of localizing proteins in cells of a tissue section exploiting the principle of antibodies binding specifically [46]

Dead birds, after necropsy, have their various tissues tested for virus by either RT-PCR or immunohistochemistry, where virus shows up as brown stained tissue because of a substrate-enzyme reaction. An autopsy, also known as a post-mortem examination, necropsy, or obduction, is a Medical procedure that consists of a thorough Examination In Molecular biology, reverse transcription polymerase chain reaction (RT-PCR is a Laboratory technique for amplifying a defined piece of a Ribonucleic Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins

Control

West Nile virus warning sign in Southern California.
West Nile virus warning sign in Southern California.

West Nile control is achieved through mosquito control, by elimination of mosquito breeding sites, larviciding active breeding areas and encouraging personal use of mosquito repellents. The Mosquito Control EP is the first studio release by American Post-metal band Isis, released in 1998 by Escape Artist An insect repellent is a substance applied to skin clothing or other surfaces which discourages Insects (and Arthropods in general from landing or climbing on that The public is also encouraged to spend less time outdoors, wear long covering clothing, apply bug repellant that contains DEET and ensure that mosquitoes cannot enter buildings. N, N -Diethyl- meta -toluamide, abbreviated DEET, is the most common active Ingredient in Insect repellents It is intended [47] Environmentalists have condemned attempts to control the transmitting mosquitoes by spraying pesticide, saying that the detrimental health effects of spraying outweigh the relatively few lives which may be saved, and that there are more environmentally friendly ways of controlling mosquitoes. Environmentalism is a broad philosophy and Social movement centered on a concern for the conservation and improvement of the environment. A pesticide is a substance or mixture of substances used to kill a pest. They also question the effectiveness of insecticide spraying, as they believe mosquitoes that are resting or flying above the level of spraying will not be killed; the most common vector in the northeastern U. S. , Culex pipiens, is a canopy feeder. The canopy is one of the uppermost levels of a Forest, below the emergent layer, formed by the Tree crowns Canopy trees refers to the trees

Treatment research

Morpholino antisense oligos conjugated to cell penetrating peptides have been shown to partially protect mice from WNV disease. In Molecular biology, a Morpholino is a Molecule used to modify Gene expression. Cell penetrating peptides (CPPs are short polycationic sequences which can facilitate cellular uptake of peptides and proteins which contain them [48] There have also been attempts to treat infections using ribavirin, intravenous immunoglobulin, or alpha interferon. Ribavirin (Copegus Rebetol Ribasphere VilonaVirazole also generics from Sandoz Teva Warrick is an Anti-viral drug which is active against a number of DNA and Antibodies (also known as immunoglobulins, abbreviated Ig) are Gamma globulin Proteins that are found in Blood or other Bodily Human type I Interferons comprise a vast and growing group of IFN proteins [49] GenoMed, a US biotech company, has found that blocking angiotensin II can treat the "cytokine storm" of West Nile virus encephalitis as well as other viruses. A cytokine storm is a potentially fatal immune reaction consisting of a Positive feedback loop between Cytokines and Immune cells with highly elevated [50]

In 2007 the World Community Grid launched a project where by computer modeling of the West Nile Virus (and related viruses) thousands of small molecules are screened for their potential anti-viral properties in fighting the West Nile Virus. This is a project which by the use of computer simulations potential drugs will be identified which will directly attack the virus once a person is infected. This is a distributed process project similar to SETI@Home where the general public downloads the World Community Grid agent and the program (along with thousands of other users) screens thousands of molecules while their computer would be otherwise idle. SETI@home ("SETI at home" is a Distributed computing ( Grid computing) project using Internet -connected computers hosted by the Space If the user needs to use the computer the program sleeps. There are several different projects running, including a similar one screening for anti-AIDS drugs. The project covering West Nile Virus is called "Discovering Dengue Drugs – Together. " The software and information about the project can be found at:

See also

Sources

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External links

(low literacy materials in Spanish for WNV prevention)

Events 1276 - While taking exile in Fuzhou in southern China, away from the advancing Mongol invaders, the remnants of the

Dictionary

West Nile virus

-noun

  1. A particular flavivirus, dangerous to humans.
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