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3 days ago · Key points. West Nile virus disease (West Nile) is caused by a virus primarily spread to people through the bite of infected mosquitoes. West Nile virus is maintained in the environment between mosquitoes and birds. People do not spread the infection other than rarely through blood transfusions, organ transplantation, and mother to baby.
West Nile virus (WNV) is the leading cause of mosquito-borne disease in the continental United States. It is most commonly spread to people by the bite of an infected mosquito. Cases of WNV occur during mosquito season, which starts in the summer and continues through fall.
Jul 3, 2023 · Neurosciences. West Nile virus: What you need to know. Deb Balzer. July 3, 2023. Female Culex mosquito, courtesy: CDC. The Centers for Disease Control and Prevention (CDC) have confirmed reports of West Nile virus in 10 states. The bite of an infected mosquito most commonly spreads the virus.
- Outbreaks
- Transmission
- Signs and Symptoms
- Diagnosis
- Treatment and Vaccine
- Vector and Animal Hosts
- Prevention
- Who Response
West Nile Virus (WNV) was first isolated in a woman in the West Nile district of Uganda in 1937. It was identified in birds (crows and columbiformes) in Nile delta region in 1953. Before 1997 WNV was not considered pathogenic for birds, but at that time in Israel a more virulent strain caused the death of different bird species presenting signs of ...
Human infection is most often the result of bites from infected mosquitoes. Mosquitoes become infected when they feed on infected birds, which circulate the virus in their blood for a few days. The virus eventually gets into the mosquito's salivary glands. During later blood meals (when mosquitoes bite), the virus may be injected into humans and an...
Infection with WNV is either asymptomatic (no symptoms) in around 80% of infected people, or can lead to West Nile fever or severe West Nile disease. About 20% of people who become infected with WNV will develop West Nile fever. Symptoms include fever, headache, tiredness, and body aches, nausea, vomiting, occasionally with a skin rash (on the trun...
West Nile virus can be diagnosed by a number of different tests: 1. IgG antibody sero-conversion (or significant increase in antibody titers) in two serial specimen collected at a one week interval by enzyme-linked immunosorbent assay (ELISA); 2. IgM antibody capture enzyme-linked immunosorbent assay (ELISA); 3. neutralisation assays; 4. viral dete...
Treatment is supportive for patients with neuro-invasive West Nile virus, often involving hospitalization, intravenous fluids, respiratory support, and prevention of secondary infections. No vaccine is available for humans.
WN virus is maintained in nature in a mosquito-bird-mosquito transmission cycle. Mosquitoes of the genus Culex are generally considered the principal vectors of WNV, in particular Cx. Pipiens. WNV is maintained in mosquito populations through vertical transmission (adults to eggs). Birds are the reservoir hosts of WNV. In Europe, Africa, Middle Eas...
Preventing transmission in horses
Since WNV outbreaks in animals precede human cases, the establishment of an active animal health surveillance system to detect new cases in birds and horses is essential in providing early warning for veterinary and human public health authorities. In the Americas, it is important to help the community by reporting dead birds to local authorities. Vaccines have been developed for horses. Treatment is supportive and consistent with standard veterinary practices for animals infected with a vira...
Reducing the risk of infection in people
In the absence of a vaccine, the only way to reduce infection in people is by raising awareness of the risk factors and educating people about the measures they can take to reduce exposure to the virus. Public health educational messages should focus on the following: 1. Reducing the risk of mosquito transmission. Efforts to prevent transmission should first focus on personal and community protection against mosquito bites through the use of mosquito nets, personal insect repellent, by wearin...
Vector Control
Effective prevention of human WNV infections depends on the development of comprehensive, integrated mosquito surveillance and control programmes in areas where the virus occurs. Studies should identify local mosquito species that play a role in WNV transmission, including those that might serve as a “bridge” from birds to human beings. Emphasis should be on integrated control measures including source reduction (with community participation), water management, chemicals, and biological contr...
The WHO regional office for Europe and WHO region of the Americas are intensively supporting WNV surveillance and outbreak response activities respectively in Europe and in North America, Latin America and the Caribbean, together with country offices and international partners.
Oct 16, 2023 · Overview. Most of the time, symptoms of West Nile virus are flu-like. Less than 1% of people develop severe nervous system symptoms. What is West Nile virus? West Nile is a virus that spreads through mosquito bites. Most people who get infected don’t have symptoms.
West Nile virus ( WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family Flaviviridae, from the genus Flavivirus, which also contains the Zika virus, dengue virus, and yellow fever virus. The virus is primarily transmitted by mosquitoes, mostly species of Culex.
Feb 6, 2014 · February 6, 2014. ANN ARBOR—Dengue fever and West Nile fever are mosquito-borne diseases that affect hundreds of millions of people worldwide each year, but there is no vaccine against either of the related viruses. A team of scientists at the University of Michigan and Purdue University has discovered a key aspect both to how the viruses ...
