West Nile Virus (WNV)
What is West Nile Virus?
The West Nile virus (WNV) is an emerging zoonotic arbovirus widely distributed across the globe, belonging to the Flaviviridae family, genus Flavivirus. First isolated in Uganda in 1937, it has since spread across Africa, Europe, Asia, the Middle East, and the Americas.
WNV poses a significant threat to animal health and public health. It is primarily transmitted to humans through mosquito bites, with a wide range of wild birds acting as natural reservoirs, aiding the spread of the virus during their migrations.
In 2024, 19 EU/EEA countries reported human cases of West Nile Virus infection: Albania, Austria, Bulgaria, Croatia, Cyprus, Czechia, France, Germany, Greece, Hungary, Italy, Kosovo, North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain and Turkey
In addition, infections were detected in animals (horses and birds) and mosquitoes, with Culex pipiens being the species most frequently positive for WNV. ¹
West Nile Fever: clinical features
West Nile Fever is a common manifestation following West Nile Virus infection. Up to 80% of infected individuals are asymptomatic.
Symptoms of WNV usually appear 3-14 days after exposure. It is estimated that 20% of infected people develop West Nile Fever with mild symptoms such as fever, headache, body aches, skin rash and swollen lymph nodes.
In severe cases, infection can lead to encephalitis or meningitis. Symptoms of severe West Nile Virus include:
- Severe headache
- High fever
- Neck stiffness
- Muscle weakness
- Stupor and disorientation
- Tremors, convulsiones, paralysis and coma.
Diagnosis of West Nile Virus
Diagnosis methods include:
- IgG seroconversion or significant rise in antibody titers between paired samples.
- Detection of IgM and IgG antibodies through ELISA or CLIA immunoassays.
- Neutralization tests.
- Virus detection via reverse transcription polymerase chain reaction (RT-PCR).
- Virus isolation in cell cultures.
IgM antibodies are detectable in nearly all serum and cerebrospinal fluid samples collected during the symptomatic phase but may persist for over a year.
Treatment and prevention of WNV
Currently, there are no licensed vaccines for human use nor specific antiviral treatments for West Nile virus infection. Management focuses on:
- Symptomatic relief with over-the-counter pain relievers
- Hospitalization for severe cases requiring IV fluids and supportive care
How to prevent West Nile virus?
Prevention focuses on avoiding mosquito bites and controlling mosquito vector populations, especially in endemic areas and during the warmer months.
Vircell’s Solutions for West Nile Virus
Amplirun® West Nile Virus RNA Control
Purified RNA of West Nile Virus to be used to control research techniques based in nucleic acids amplification.
- Purified complete microbial genome
- Any sequence can be amplified
- Concentration range: 12.500-20.000 copies/µl determined by qPCR
- Can be used in any molecular testing platform
- Non infectious
- Lyophilized presentation
- A resuspension vial is provided within the kit with Molecular Biology Grade Water
West Nile Virus VirClia®
Indirect chemiluminescent immunoassay (CLIA) to test antibodies against West Nile virus in human serum/plasma.
- Monotest format with ready-to-use reagents
- Simple and automated protocol with fast results
- Provides outstanding flexibility and easy handling to clinical laboratories
- Each monodose includes a calibrator and a negative control that enables the validation and interpretation of results for each individual sample
- Allows pipetting from primary sample tube, no further manipulation is needed
VIRAL MENINGITIS REALTIME PCR KIT
Real Time PCR kit for the one-step detection of the main agents causing viral meningitis in human cerebrospinal fluid samples
- Simultaneous analysis of 7 pathogens, including West Nile Virus (WNV), HSV-1, HSV-2, VZV, EVs, HPeVs, WNV and TOSV.
- Bacteriophage MS2 RNA internal control to ensure assay integrity.
- Suitable for 5-channel qPCR cyclers: FAM, HEX (VIC), Q705 (Cy5.5), Texas Red (ROX) and Cy5.
- Fast and reliable results in under 2 hours.
- Lyophilized master mix and positive control to ensure stability and reduce transportation costs.
- Different kit presentations for greater user convenience: vials and pre-dispensed strip-divisible plate
Bibliography
- European Centre for Disease Prevention and Control, European Food Safety Authority, Surveillance, prevention and control of West Nile virus and Usutu virus infections in the EU/EEA. Stockholm: 2023.