Mosquitoes can transmit diseases such as malaria, dengue fever, yellow fever, Zika, and several types of encephalitis.  They can also transmit heart worms to dogs.  According to the Centers for Disease Control (CDC), mosquito-borne diseases infest about 70 million people each year and are responsible for the deaths of approximately 3 million.  In fact, some scientists claim that mosquito-borne disease will be responsible for over half the world's deaths over time and that mosquitoes will continue to be the most dangerous insect to humans.

West Nile Virus (WNV) is a type of encephalitis commonly found in Africa, Europe, Western and Central Asia, Oceania, the Middle East and most recently North America.  It was first discovered in an ailing woman in the West Nile District of Uganda in 1937, hence the name West Nile Virus.  The virus first emerged in the United States in 1999 in New York City.  Experts are not sure how WNV was transported to the US.  It could have been through bird migration, the introduction of birds or mosquitoes that were infected with the virus or even persons travelling to New York from foreign countries.  Regardless of how it arrived here, West Nile Virus continued  to spread rapidly throughout most of the U.S. from 2001 through 2005, and it continues to be a problem in many states to this day.

According to the CDC, mosquitoes become infected with WNV after feeding on a host carrying the virus in its blood.  The mosquito carries the virus in its saliva and can transmit it to another bird, a person, or an animal when obtaining a blood meal.

Most people who are infected with WNV will never develop symptoms.  Those who do will experience symptoms similar to mild illness with fever, body aches, and sometimes a skin rash with swollen glands.  Symptoms typically start 3 to 15 days after the bite of an infected mosquito.  Reportedly, once you have the virus, lifetime immunity results.  

In rare cases, the virus crosses the blood-brain barrier where it will interfere with central nervous system functioning and cause inflammation of brain tissue.  This severe illness know as West Nile Encephalitis causes headaches, high fever, stiff neck, stupor, disorientation, coma, tremors, convulsions, muscle weakness, and paralysis.  Less than one percent of those infected with the virus will experience the severe neurological illness and of the one percent, three to fifteen percent may actually die.

There is no specific treatment for the virus.  West Nile Encephalitis can be treated via hospitalization, intravenous fluids, respiratory support, good nursing care and the prevention of secondary infections such as pneumonia or urinary tract infections.