This is a virus that spreads to humans through mosquito bites. It is called West Nile virus, and most infected people do not experience any symptoms. As per studies, only 1 in 5 people have symptoms such as rash, headaches, muscle aches, and fever. This virus may rarely cause life-threatening conditions in the brain and spinal cord. For example, encephalitis and meningitis.
The name of this virus comes from the district of Uganda where it was first identified.
Generally, this virus lives in multiple parts of the world (such as North America, Europe, Africa, the Middle East, Australia, and Asia). Furthermore, it is considered one of the most common viruses that is spread by mosquitoes in the U.S. Approximately 50,000 symptomatic cases have occurred in the U.S. since 1999, when the first case was identified.
Symptoms
People with West Nile virus usually experience the following symptoms. These include:
- Nausea
- Vomiting
- Muscle aches
- Fever
- Swollen lymph nodes
- Rash
- Diarrhea
- Headaches
- Sore throat
- Pain behind the eyes
Approximately 1% of people who get this virus develop life-threatening diseases (such as meningitis and encephalitis). Check below some symptoms:
- Confusion
- Muscle weakness
- Tremors or convulsions (uncontrollable movements)
- Seizures
- Paralysis
- Coma
- Neck stiffness
- High fever (higher than 103 degrees Fahrenheit or 39.5 degrees Celsius)
- Severe headaches
If any of the previous symptoms occur, immediately go to the nearest emergency room or call 911 in the U.S. or the emergency number in your country.
Causes
This type of virus is an arbovirus (also known as a virus that you can get from arthropods). Arthropods are larger groups of insects. In other words, it is an RNA virus in the genus Flavivirus that is very similar to the virus that often causes dengue fever, yellow fever, and Zika.
You may wonder how humans get this virus. Usually, the virus enters the body through a mosquito bite. Mosquitoes get this virus from certain birds. Thereafter, the virus begins to multiply inside a mosquito. It may also spread the virus to animals. Commonly, the incubation period is from 6 to 14 days. This is the period before symptoms begin to appear. Rarely, the West Nile virus may spread:
- From pregnant women to their babies
- Through breast milk or a blood transfusion
- Through an organ transplant
Furthermore, this is not a contagious condition. It means the virus cannot spread from one person to another.
Risk Factors
Healthcare professionals have identified some factors that may increase your risk of developing this disease. Check below some examples:
- Older people (over 60 years old)
- During an organ transplant
- Cancer
- Diabetes
- Hypertension (high blood pressure)
- Kidney disease
What Are The Potential Complications of West Nile Virus?
Only a few people develop serious complications and severe symptoms with this condition. One of the most common complications is swelling in the nervous system (the brain and spinal cord). When it occurs, you may develop meningitis or encephalitis. Check below for other complications of this disease:
- Hearing loss (also called deafness)
- Memory loss
- Muscle weakness
- Unusual reflexes
- Mental health problems (such as depression, anxiety, and others)
- Walking problems
- Gait disorders
- Vision loss (blindness)
- Myocarditis (inflammation of the heart)
- Pancreatitis
- Rhabdomyolysis
- Retinal hemorrhages
This document does not contain a full list of West Nile complications. Seek emergency care if you develop any of the previous ones.
How to Prevent West Nile Virus?
Nowadays, there are no vaccines that help prevent this type of virus. However, some tips may help reduce the risk of getting it. For example:
- Avoiding high-risk times – It is recommended to stay indoors when mosquitoes are most active (such as in the morning and around sunset).
- Use insect repellent – If you live or travel in regions where the condition is common, you should use a spray insect repellent, especially when outdoors.
- Cover the skin – You should wear long pants or a long-sleeved shirt when outdoors.
- Drain standing water – You should empty spaces and areas where water may collect, including a birdbath or clogged rain gutters, because mosquitoes could breed in those places.
- Keep doors and windows closed – It helps prevent mosquitoes from entering the home.
- Take precautions if you decide to sleep outdoors
Diagnosis
Healthcare professionals may perform a cerebrospinal fluid (CSF) or blood test to check for antibodies and other irregularities linked to the infection. In severe cases, previous tests are enough to diagnose the condition. Doctors may also perform some imaging tests if you develop brain or spinal cord inflammation. These include a CT (computerized tomography) scan or an MRI (magnetic resonance imaging) scan.
Treatment
Generally, there are no antiviral medications that may treat this infection. For people with mild or no symptoms, physicians recommend over-the-counter (OTC) medicines similar to those that people take for a cold or flu.
If you develop neurological symptoms, you may be hospitalized. Check below some treatments doctors often prescribe to reduce brain swelling:
- Antiseizure medicines
- Intravenous (IV) fluids to prevent or treat dehydration
- Supplemental oxygen or mechanical ventilation for people who experience breathing problems
- Corticosteroids to lessen inflammation
- Tube feeding (it is recommended when you cannot feed yourself)
Frequently Asked Questions
Can you ever get rid of West Nile virus?
Usually, the immune system fights off this type of virus. However, if you have a weakened immune system and get this virus, you may develop permanent damage to the nervous system. For more details, discuss it with your doctor.
How long does West Nile virus last?
People who have had mild symptoms usually recover completely within several weeks, but extreme tiredness and muscle weakness may last for months. In severe cases, if you do not get immediate treatment, damage caused by the virus to the nervous system can be permanent.
Is West Nile virus fatal?
In general, this condition is treatable. Approximately 1 in 1,500 people die from West Nile virus. However, if a person develops infections of the nervous system, the risk of death increases to 10% or 1 out of 10 people.
When should I go to the ER?
If any of the following symptoms occur, immediately go to the nearest emergency room (ER) or call 911 in the U.S. For example:
- Severe headaches
- Confusion
- Severe muscle weakness
- Seizures
- High fever
- Neck stiffness
Ask your healthcare professional if you have additional questions.
