Mosquito-Borne Diseases
Diseases Locally Transmitted
- West Nile Virus (View FAQ)
- St. Louis Encephalitis
- Western Equine Encephalomyelitis
- Canine Heartworm Disease
Potential Local Transmission
If you are a resident of the District:
CALL (310) 915-7370
to report mosquito issues, or:
CALL (877) WNV-BIRD
to report a dead bird, or visit:
St. Louis Encephalitis (SLE)
What is SLE?
SLE is a viral disease caused by a virus spread by infected Culex mosquitoes. It is endemic to California, though relatively rare. The last important California outbreak occurred in 1989.
Symptoms
General
- Many infected will have no apparent illness.
Severe Infection
- Fever, headache, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions (especially in infants) and spastic (but rarely flaccid) paralysis.
More Information
Western Equine Encephalomyelitis (WEE)
What is WEE?
WEE is a viral disease spread by infected Culex mosquitoes which mainly affects horses, and infrequently, humans.
Symptoms
General
- Many infected will have no apparent illness.
Severe Infection
- Fever, headache, neck stiffness, stupor, disorientation, coma, tremors, occasional convulsions and paralysis.
Canine Heartworm
What is Canine Heartworm?
Canine Hearteworm is an infection in animals caused by a worm, Dirofilaria immitis, which is spread by mosquito bites. Dogs, cats, ferrets, wolves, coyotes, seals, and sea lions can all become infected.
Symptoms
- Tiredness, problems breathing, coughing, and heart failure.
- Infected cats may breathe hard and be more likely to vomit.
- Infection can be present for a while in the pet before symptoms appear.
Dengue Fever
What is Dengue Fever?
Dengue Fever is a viral infection transmitted to people by the bite of an infected Aedes mosquito. It is estimated that there are over 100 million cases of dengue worldwide each year.
Symptoms
General
- High fever, severe headache, severe pain behind the eyes, joint pain, muscle and bone pain, rash, and mild bleeding (e.g., nose or gums bleed, easy bruising).
Severe Infection
- Internal bleeding, shock and death.
Yellow Fever
What is Yellow Fever?
Yellow Fever is a viral infection transmitted to people by the bite of an infected Aedes mosquito. It occurs in tropical and subtropical areas in South America and Africa. Yellow fever virus is a very rare cause of illness in U.S. travelers to these areas.
Symptoms
General
- Fever, chills, severe headache, back pain, general body aches, nausea and vomiting, fatigue, and weakness.
Severe Infection
- High fever, jaundice, internal bleeding (especially from the gastrointestinal tract), shock, failure of many organs, and death.
More Information
Centers for Disease Control and Prevention Yellow Fever Information
Chikungunya
What is Chinkungunya?
Chinkungunya is a viral infection transmitted to people by the bite of an infected Aedes mosquito. Outbreaks have occurred in parts of Africa, Europe, Southeast Asia, islands in the Indian and Pacific Oceans, Florida, Puerto Rico, and the U.S. Virgin Islands.
Symptoms
- Fever, severe joint pain, headache, muscle pain, or rash.
Malaria
What is Malaria?
Malaria is a serious and sometimes fatal disease transmitted by Anopheles mosquitoes. Locally-transmitted malaria is now rare in California. Today over 99 percent of the malaria cases diagnosed in U.S. residents are acquired during travel to other countries.
Symptoms
General
- Fever and flu-like illness: Chills, headache, muscle aches, tiredness, nausea, vomiting, and diarrhea.
Severe Infection
- May cause kidney failure, seizures, mental confusion, coma, and death.
If you think you, a family member, or a pet might have a mosquito-borne disease, consult a healthcare provider for a proper diagnosis.