Mosquitoes transmit a vast number of viruses, with researchers having identified more than 4,000mosquito virus isolates. While thousands exist, only a small fraction (about 12 types in the U.S.) are known to regularly spread germs that make people sick. Centers for Disease Control and Prevention | CDC (.gov) +1

Most Common Mosquito-Borne Viruses 

The four most widespread and notorious viruses that cause significant human suffering worldwide are: National Institutes of Health (.gov)

• Dengue Virus: Affects nearly 390 million people annually and is endemic in over 100 countries.
• Yellow Fever Virus: Most common in tropical areas of Africa and South America; it causes approximately 30,000 deaths every year.
• Zika Virus: Often asymptomatic but can cause serious birth defects if a pregnant woman is infected.
• Chikungunya Virus: Known for causing severe and sometimes chronic joint pain. World Mosquito Program +4

Key Viruses Found in the United States

In the U.S., public health officials primarily track several specific “zoonotic” viruses (those maintained in animal-mosquito cycles): National Institutes of Health (.gov)

• West Nile Virus (WNV): The leading cause of mosquito-borne disease in the contiguous U.S..
• Eastern Equine Encephalitis (EEE): A rare but very serious virus with a high fatality rate (30% to 60%).
• La Crosse Encephalitis (LAC): Primarily affects children under 16, mostly in the Midwestern U.S..
• St. Louis Encephalitis (SLE): Historically common in the U.S., it primarily affects the elderly during late summer.
• Jamestown Canyon Virus: An emerging threat recently confirmed in states like Michigan. Centers for Disease Control and Prevention | CDC (.gov) +2

Other Mosquito-Borne Pathogens

It is important to note that while the user asked about viruses, mosquitoes also transmit other types of deadly pathogens, such as: 

• Parasites: Most notably Malaria, which kills over 600,000 people annually, and Lymphatic Filariasis.
• Bacteria: Though rarer, they can transmit bacteria like Francisella tularensis(Tularemia). Wikipedia +4

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This is for informational purposes only. For medical advice or diagnosis, consult a professional. AI responses may include mistakes. Learn more