West Nile, dai sintomi alle cure: cosa sapere sul virus trasmesso dalla zanzara

Un 83enne è morto in Veneto per una grave forma di encefalite dovuta al virus West Nile, cui era risultato positivo. Il virus fa parte della famiglia dei Flaviviridae ed è stato isolato per la prima volta nel 1937 in Uganda. È diffuso in Africa, Asia occidentale, Europa, Australia e America. Ma negli ultimi anni sta circolando anche in Italia, soprattutto al Nord. L’Iss spiega che è grave solo in anziani e fragili, i casi sono spesso asintomatici

epa03367655 A handout image made available on 22 August 2012 from the Centers for Disease Control showing a Culex quinquefaciatus female mosquito feeding on human blood. This species is a known vector for West Nile Virus. The female C. quinquefasciatus mosquito is known as one of the many arthropodal vectors responsible for spreading the West Nile virus to human beings through their bite when obtaining a blood meal. Mosquitoes of the Culex species lay their eggs in the form of egg rafts that float in still or stagnant water. The mosquito lays the eggs one at a time sticking them together in the shape of a raft. An egg raft can contain from 100 to 400 eggs. The eggs go through larval and pupal stages and feed on micro-organisms before developing into flying mosquitoes. The CDC is reporting that there have currently been 1,100 cases of West Nile Virus reported in the US in 2012, more than ever reported at this point in the year since the virus was first recorded in the US in 1999. EPA/JIM GATHANY / CENTERS FOR DISEASE CONTROL / HANDOUT HANDOUT EDITORIAL USE ONLY/NO SALES

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La “Febbre del Nilo”, che ha causato la morte in Veneto di un 83enne, e che nel 2020 ha fatto 5 morti, è provocata da un virus che ha come serbatoi uccelli e zanzare, le cui punture sono il principale mezzo di trasmissione all'uomo

GUARDA IL VIDEO: West Nile, cosa sapere sul virus trasmesso dalla zanzara

epa03367649 A handout image made available on 22 August 2012 from the Centers for Disease Control showing an electron micrograph of the West Nile virus.. Experts believe WNV is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall. This fact sheet contains important information that can help you recognize and prevent West Nile virus. The CDC is reporting that there have currently been 1,100 cases of West Nile Virus reported in the US in 2012, more than ever reported at this point in the year since the virus was first recorded in the US in 1999. EPA/CYNTHIA GOLDSMITH / CENTERS FOR DISEASE CONTROL / HANDOUT HANDOUT EDITORIAL USE ONLY/NO SALES

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Il West Nile Virus fa parte della famiglia dei Flaviviridae ed è stato isolato per la prima volta nel 1937 in Uganda, appunto nel distretto West Nile. È diffuso in Africa, Asia occidentale, Europa, Australia e America. Ma negli ultimi anni sta circolando anche in Italia, soprattutto al Nord

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epa000236429 (FILES) An undated pictue of a mosquito "Anopheles quadrimaculatus", The authorities of the health department of Florida reported on Tuesday, 20 July 2004, at least four cases of persons infected with the Nile virus in Miami-Dade county. The mosquito ''Anopheles quadrimaculatus'' is the most important vector carrying the malaria virus in the United States, and is a species found in West Nile Virus positive mosquito pools in the USA. EPA/U.S. Centers for Disease Control and Prevention

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La maggior parte delle persone infette - spiega il sito dell'Istituto Superiore di Sanità (Iss) - non mostra alcun sintomo. Fra i casi sintomatici, circa il 20% presenta sintomi leggeri come febbre, mal di testa, nausea, vomito, sfoghi cutanei

Veneto, morto anziano colpito da West Nile

epa03367653 A handout image made available on 22 August 2012 from the Centers for Disease Control showing a transmission electron micrograph (TEM) revealing the presence of West Nile virus virions in a tissue sample. Experts believe WNV is established as a seasonal epidemic in North America that flares up in the summer and continues into the fall. This fact sheet contains important information that can help you recognize and prevent West Nile virus. The CDC is reporting that there have currently been 1,100 cases of West Nile Virus reported in the US in 2012, more than ever reported at this point in the year since the virus was first recorded in the US in 1999. EPA/CYNTHIA GOLDSMITH / CENTERS FOR DISEASE CONTROL / HANDOUT HANDOUT EDITORIAL USE ONLY/NO SALES

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I sintomi più gravi si presentano in media in meno dell'1% delle persone infette, in genere anziani o soggetti debilitati, e comprendono febbre alta, forti mal di testa, debolezza muscolare, disorientamento, tremori, disturbi alla vista, torpore, convulsioni, fino alla paralisi e al coma

Febbre del Nilo: cos'è e come si cura la malattia provocata dal virus West Nile

374626 03: Bacteriologist Erik Devereaux tests mosquitos for the West Nile Virus July 28, 2000 at the State Lab in Boston, MA. Officials say a dead crow found in Hopkinton, MA on July 21, 2000 was the second confirmed case of the mosquito-borne disease found in the Northeast. (Photo by Darren McCollester/Newsmakers)

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La febbre West Nile non si trasmette da persona a persona tramite il contatto con le persone infette. Il virus infetta anche altri mammiferi, soprattutto equini, ma in alcuni casi anche cani, gatti, conigli

epa03367657 A handout image made available on 22 August 2012 from the Centers for Disease Control showing a Culex quinquefaciatus female mosquito . This species is a known vector for West Nile Virus. The female C. quinquefasciatus mosquito is known as one of the many arthropodal vectors responsible for spreading the West Nile virus to human beings through their bite when obtaining a blood meal. Mosquitoes of the Culex species lay their eggs in the form of egg rafts that float in still or stagnant water. The mosquito lays the eggs one at a time sticking them together in the shape of a raft. An egg raft can contain from 100 to 400 eggs. The eggs go through larval and pupal stages and feed on micro-organisms before developing into flying mosquitoes. The CDC is reporting that there have currently been 1,100 cases of West Nile Virus reported in the US in 2012, more than ever reported at this point in the year since the virus was first recorded in the US in 1999. EPA/JIM GATHANY / CENTERS FOR DISEASE CONTROL / HANDOUT HANDOUT EDITORIAL USE ONLY/NO SALES

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Il periodo di incubazione dal momento della puntura della zanzara infetta varia fra 2 e 14 giorni, ma può essere anche di 21 giorni nei soggetti con deficit a carico del sistema immunitario

LOUISVILLE, KY - AUGUST 25: Rochelle Ransom a Louisville Metro Department of Public Health and Wellness lab technologist processes liquified mosquito samples in the lab at Health Department headquarters on August 25, 2021 in Louisville, Kentucky. For mosquito control and tracking of mosquito-borne diseases, female mosquitos are collected, frozen, and brought to the laboratory techs. Hong and Ransom then liquify the mosquito tissue with a lyser, separate the solids with a centrifuge, and then place it into a machine that extracts viral RNA to then be tested in a thermal cycler for pathogens. Samples are tested for Saint Louis encephalitis, West Nile virus, La Crosse encephalitis, and Eastern equine encephalitis.(Photo by Jon Cherry/Getty Images)

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La diagnosi viene prevalentemente effettuata attraverso test di laboratorio (Elisa o Immunofluorescenza) effettuati su siero e, dove indicato, su fluido cerebrospinale, per la ricerca di anticorpi del tipo IgM

epa08616179 A handout photo made available by the Town Hall of Palomares del Rio shows a municipal worker fumigating a field in Palomares del Rio, Seville, Spain, 21 August 2020, in an attempt to exterminate the mosquitoes transmitting the West Nile Virus. An 85-year-old woman died on 21 August becoming the second victim of this virus while a total of 25 cases have been detected. The West Nile Virus is transmitted to humans by mosquitoes and can also affect birds, horses and other mammals. According to the World Health Organization (WHO) up to an 80 percent of infected people do not show any symptoms, while the other 20 per cent do present them and their diagnosis is far more serious and can give way to encephalitis or meningitis that can cause cerebral damage and even death. EPA/Town Hall of Palomares del Rio HANDOUT HANDOUT EDITORIAL USE ONLY/NO SALES

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Non esiste un vaccino per la febbre West Nile. Attualmente sono allo studio dei vaccini, ma per il momento - spiega l'Iss - la prevenzione consiste soprattutto nel ridurre l'esposizione alle punture di zanzare

Flavivirus (family Flaviviridae), these viruses are responsible for yellow fever, dengue fever, Japanese encephalitis, Zika virus, West Nile encephalitis. They are transmitted by mosquitoes or ticks. image produced from transmission electron microscopy (viral diameter approximately 40 to 60 nm). (Photo by: CAVALLINI JAMES/BSIP/Universal Images Group via Getty Images)

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Non esiste neanche una terapia specifica. Nella maggior parte dei casi, i sintomi scompaiono da soli dopo qualche giorno o possono protrarsi per qualche settimana

WHEELING, IL - JUNE 20: Lab assistant Amy Sebo drops mosquitoes into test tubes as she prepares them to be tested with the VecTest procedure for West Nile Virus, Saint Louis Encephalitis, Eastern Equine Encephalitis and Antigen Panel Assay June 20, 2003 at the Northwest Mosquito Abatement District headquarters in Wheeling, Illinois. Illinois reported 884 cases and 64 deaths from the West Nile Virus last year, the highest amount in the nation. (Photo by Tim Boyle/Getty Images)

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Nei casi più gravi è invece necessario il ricovero in ospedale, dove i trattamenti somministrati comprendono fluidi intravenosi e respirazione assistita