West Nile Fever: what is it, how dangerous is it, how do you get it, and should you vaccinate?

What is West Nile Fever?

• West Nile fever, or West Nile fever, is an infectious disease caused by the West Nile virus, which is transmitted by various mosquito species.
• Although West Nile fever is usually relatively harmless, in some cases it can be a life-threatening illness.
• The West Nile virus is common in birds and regularly jumps to horses and humans.
• The West Nile virus is closely related to dengue, tick-borne encephalitis, and Zika, among others, and periodically causes severe local outbreaks.
• The disease owes its name to the first cases in Uganda in the Nile region; however, the disease has since spread far beyond the Nile region.

Where is West Nile virus found?

• The mosquitoes that can transmit West Nile virus are found worldwide, except for the far north.
• The West Nile virus is currently mainly found in Africa, parts of Asia and North America, and around the Mediterranean. In recent years, more cases have been reported in Europe.
• Climate change appears to play a significant role in the spread of West Nile virus in Europe and the US.
• In Latin America and Australia, there are still very few human infections, but the virus is already present in birds. Mutations in the virus could cause a sudden outbreak there as well.

What are the symptoms of West Nile fever?

• The first symptoms appear two to six days after infection with West Nile virus.
• Some common symptoms in a mild case include: flu-like illness with fever, headache, muscle aches, sometimes abdominal discomfort, diarrhea, rash, and enlarged lymph nodes.
• Approximately 80% of infected people experience no symptoms at all, around 20% experience mild symptoms, and less than 1% experience severe symptoms.
• Severe symptoms include: severe neurological problems, such as encephalitis or meningitis. These symptoms can lead to a coma and even death.
• Older or vulnerable people are at greater risk of a severe course of West Nile fever.

Can West Nile fever be treated?

• Once infected, there is no treatment for West Nile virus.
• The disease usually clears up on its own within a week.
• Treatment focuses primarily on managing pain and fever, with medications such as paracetamol.
• Prevent dehydration by drinking plenty of fluids. Seek immediate medical attention if you experience persistent high fever, severe headache, stiff neck, drowsiness, confusion, paralysis, or seizures.

Are there vaccinations against West Nile fever?

• No, there is currently no vaccine for West Nile fever for humans; only a vaccine is available for horses.
• Once you have overcome West Nile virus, whether or not you've been infected, as far as we know, you are protected against future infections.

How can you prevent West Nile fever?

• Stay informed about local outbreaks, especially in Southern Europe and the US, where the virus only occurs periodically with local outbreaks.
• Avoid being bitten by mosquitoes! In many areas where West Nile fever is prevalent, mosquitoes transmit several nasty diseases.
• It is advisable to wear protective clothing that covers your arms and legs and to apply mosquito repellent containing DEET. Air conditioning and window screens also offer partial protection.
• Sleeping under a mosquito net is recommended; the greatest risk of an infected mosquito bite is around sunset, in the evening, and around sunrise.