Summary about Disease
West Nile virus (WNV) infection is a disease primarily spread to humans through the bite of infected mosquitoes. Most people infected with WNV do not develop any symptoms. However, about 20% of infected individuals will develop West Nile fever, a flu-like illness. A small percentage (less than 1%) develop a serious neurologic illness such as encephalitis or meningitis. WNV is maintained in a cycle between mosquitoes and birds.
Symptoms
Most people infected with West Nile virus do not experience any symptoms. When symptoms do occur, they can include:
Mild Infection (West Nile Fever): Fever, headache, body aches, fatigue, skin rash (occasionally), swollen lymph glands, and eye pain.
Severe Infection (West Nile Encephalitis or Meningitis): High fever, severe headache, stiff neck, disorientation, tremors, seizures, paralysis, coma, and vision loss.
Causes
West Nile virus infection is caused by the West Nile virus, which is primarily transmitted to humans through the bite of infected mosquitoes. Mosquitoes become infected when they feed on infected birds, which serve as the natural reservoir for the virus. The virus can also rarely be spread through blood transfusions, organ transplants, or from a mother to her baby during pregnancy, delivery, or breastfeeding.
Medicine Used
4. Medicine used There is no specific antiviral treatment for West Nile virus infection. Treatment is primarily supportive, aimed at relieving symptoms.
Mild Infection (West Nile Fever): Rest, fluids, and over-the-counter pain relievers (such as acetaminophen or ibuprofen) to manage fever and aches.
Severe Infection (West Nile Encephalitis or Meningitis): Hospitalization, intravenous fluids, pain medication, respiratory support (if needed), and prevention of secondary infections.
Is Communicable
West Nile virus is generally not considered communicable from person to person through casual contact. It's primarily transmitted through mosquito bites. However, rare instances of transmission have been reported through blood transfusions, organ transplants, or from mother to child during pregnancy, delivery, or breastfeeding.
Precautions
Preventing mosquito bites is the most effective way to reduce the risk of West Nile virus infection:
Use insect repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-menthane-diol (PMD), or 2-undecanone.
Wear long-sleeved shirts and pants when outdoors.
Take steps to control mosquitoes inside and outside your home.
Install or repair screens on windows and doors.
Empty standing water from containers such as flowerpots, gutters, buckets, pool covers, birdbaths, and trash cans.
Avoid being outdoors during peak mosquito biting times (dusk and dawn).
How long does an outbreak last?
West Nile virus outbreaks typically occur during mosquito season, which varies depending on the geographic location and climate. In temperate regions, outbreaks usually start in the summer and continue into the fall, until the first frost kills off the mosquito population. The duration of an outbreak can vary from a few weeks to several months.
How is it diagnosed?
West Nile virus infection is typically diagnosed through blood or cerebrospinal fluid (CSF) tests. These tests look for the presence of the virus itself or antibodies produced by the body in response to the infection. Common diagnostic tests include:
Blood Tests: ELISA (enzyme-linked immunosorbent assay) and other antibody tests to detect IgM and IgG antibodies.
Cerebrospinal Fluid (CSF) Tests: If neurological symptoms are present, a lumbar puncture (spinal tap) may be performed to collect CSF for testing.
PCR (Polymerase Chain Reaction): Can detect the virus's genetic material in blood or CSF samples.
Timeline of Symptoms
9. Timeline of symptoms
Incubation Period: 2 to 14 days after being bitten by an infected mosquito. Most people show no symptoms.
West Nile Fever (Mild): Symptoms appear suddenly and last for a few days to several weeks.
West Nile Encephalitis/Meningitis (Severe): Symptoms typically develop rapidly and can progress over several days to weeks. Neurological symptoms may persist for weeks, months, or even be permanent in some cases.
Important Considerations
Most people infected with WNV will not get sick.
The risk of serious illness is higher for people over the age of 60 and individuals with certain medical conditions, such as diabetes, hypertension, kidney disease, or weakened immune systems.
There is no vaccine for West Nile virus available for humans.
Consult a healthcare professional if you develop symptoms that could be related to West Nile virus, especially if you have been bitten by mosquitoes or live in an area where the virus is present.
Report dead birds to your local health department as they monitor WNV activity.