West Nile Virus (WNV) is a single stranded RNA virus and a member of a strain of encephalitic (inflammation of the brain) antigen complexes. The lack of the presence of the protein CCR5 in humans makes one more susceptible to this virus but less susceptible to HIV (Human Immunodeficiency Virus). According to the National Institute of Health (NIH) this lack of protein is present in approximately 1% of the population. WNV is transmitted, primarily, through infected mosquitoes. WNV cross contaminates from a cycle of birds and mosquitoes.
At highest risk to develop symptoms of WNV are individuals over the age of 50. According to the Center for Disease Control (CDC) approximately 80% of individuals, who contract WNV, do not demonstrate symptoms. The common symptoms for WNV range from fever, headache (the prominent feature), fatigue, skin rash, swollen lymph glands, and eye pain.
Mosquito season for most of the United States, starts in spring and may end in September. Once bitten by an infected mosquito, the incubation period for WNV is two to 14 days; longer periods of incubation have been documented in immuno-suppressed people. The most efficient diagnosis of WNV is by a blood test that detects the antibody IgM after eight days of the illness. This test is often done when severe symptoms of the disease, that involve WNV such as: Encephalitis, Meningitis (specific tissues of the brain), and Poliomyelitis (severe weakness of the body). Fortunately, severe WNV cases are uncommon and are associated with additional symptoms of gastrointestinal (stomach distress) symptoms, optic neuritis, seizures, weakness, change in mental status changes, seizures, flaccid paralysis (rare), and inflammation of the heart and pancreas.
Immunity of WNV develops through our white blood cells of T-lymphocytes or memory cells. This production of immune cells produces, through exposure to the virus, stays within our body for long periods of time and will likely last throughout our life span. There is currently not a vaccine for the virus.
The best preventative steps, to minimize transmission of WNV, are in avoiding mosquito bites. A nationwide “Fighting the Bite” campaign, promoted by the CDC, includes:
• Applying insect repellent containing DEET.
• Wearing clothing that covers the skin and is sprayed with DEET or Permethrin.
• Drain standing water in the home and outdoors whenever possible.
• Clean clutter and litter in yards and fields that may hold water.
• Use screens on windows and doors whenever possible.
• Report dead birds to local authorities and do not handle.
• You may obtain, through your local Public Health Department, community education & handouts to support a neighborhood campaign to “Fight the Bite”.
Thank you for asking this important and timely question.
Related articles
- More mosquitoes found in Boston with West Nile virus (boston.com)
- Dead Birds With West Nile Jump to 18 in Cerritos! a Los Cerritos Community News Alert! (economy4abc.blogspot.com)
- Health department wants help spotting dead crows (pnwlocalnews.com)
{ 2 comments }

















