Easy as Health
- Health Information for a Better Life
What are the symptoms of West
Nile (WN) virus infection?
Many infected people have no symptoms and do not get sick or have
only mild symptoms. When infection does cause illness, symptoms will
usually appear within two to 15 days. The extent and severity of
symptoms vary widely from person to person.
In mild cases, there may be flu-like symptoms, including fever,
headache and body aches. Some people may also develop a mild rash,
or swollen lymph glands.
Some individuals have weaker immune systems, and they are at greater
risk of developing symptoms and health effects that are more
serious, including meningitis and encephalitis. Meningitis is
inflammation of the lining of the brain or spinal cord. Encephalitis
is inflammation of the brain itself. These conditions can be fatal.
In such cases, symptoms could include the rapid onset of severe
headache, high fever, stiff neck, nausea, difficulty swallowing,
vomiting, drowsiness, confusion, loss of consciousness, lack of
coordination, muscle weakness and paralysis. During 2002, several
other symptoms of WN virus were identified including movement
disorders, parkinsonism, poliomyelitis-like syndrome and muscle
degeneration. Anyone who has a sudden onset of these symptoms should
seek immediate medical attention.
Who is at risk for serious health effects from WN virus?
While persons of any age and health status can be at risk for
serious health effects associated with West Nile virus infection,
the overall risk of serious health effects increases with age.
People with weaker immune systems are considered to be at greater
risk for serious health effects. This higher risk group includes:
-
people with chronic
diseases, such as cancer, diabetes, alcoholism, or heart disease
-
people that require
medical treatment that may weaken the immune system, i.e.
chemotherapy.
Although individuals
with weaker immune systems are at greater risk, WN virus can cause
severe health effects for people of any age and any health status.
This is why it is so important to reduce the risk of getting bitten
by mosquitoes. Anyone exposed to mosquitoes in an area where WN
virus has been detected is at some degree of risk for infection.
What are the long-term effects of WN virus?
Because WN virus is an emerging disease, the long-term effects are
not fully understood. Studies to date show that some people with
serious symptoms and health effects recover completely, while others
experience prolonged health problems. These problems can include:
-
physical effects, such
as long-term muscle weakness and paralysis, fatigue and headache
-
cognitive effects,
such as confusion, depression, problems with concentration and
memory loss
-
functional effects,
such as difficulty with preparing meals, going out, shopping, etc.
Scientists do not know
why some people recover while others continue to have varying
degrees of health problems.
