There have been no known human infections of these diseases in California since Aedes emerged in 2013, but there have been more than 4,100 cases of West Nile virus resulting in 202 deaths in the same period. In Tulare County, there have been 117 human cases of West Nile infection and one related death since 2013.
“Aedes aegypti is certainly a future threat that we are working to minimize, but Culex is a threat right now,” said Mir Bear-Johnson, deputy director of the Delta Mosquito and Vector Control District, which covers the northwest of the county. of Tulare. “Aedes is more annoying but Culex is more dangerous.”
West Nile is a type of encephalitis, an infection of the brain. Although most individuals experience little or no effects, mild symptoms may include fever, headache, body aches, rash, and swollen lymph nodes, while severe symptoms include disorientation, coma, tremors, convulsions, paralysis and even death. Culex mosquitoes carry two other types of brain infections.
St. Louis encephalitis virus (SLEV) belongs to the same family of viruses as West Nile virus and most infected people show few or no symptoms. The most common symptoms are mild flu-like symptoms, including fever and headache, five to 15 days after infection. Severe cases can affect the central nervous system, resulting in meningitis and/or encephalitis, and can lead to death or long-term disability. Western equine encephalitis does not manifest until 4-10 days after transmission and common symptoms include fever, headache, vomiting, diarrhea and drowsiness. The most severe cases include convulsions, can lead to coma, and one-third of those infected die.
To raise awareness and educate Californians about the public health threat that mosquitoes pose to our communities, Mosquito Awareness Week is observed April 17-23.