The gravid trap uses hay infused (stinky) water to attract gravid (pregnant) blood-fed mosquitoes. These traps are set out at the same time and in close proximity to the EVS trap sites. Gravid traps are also important in collecting mosquitoes for virus testing, because the blood-fed mosquitoes are more likely to contain virus. The mosquitoes are also sent to CDPH for testing.
The sentinel chicken flocks serve as an early warning system for the detection of SLE, WEE, and WNV transmitted by mosquitoes within the district boundaries. Blood samples are taken bi-weekly from the sentinel chickens and analyzed by the CDPH’s Viral and Rickettsial Disease Lab to determine the presence of virus antibodies, indicating whether mosquitoes in the area have transmitted a virus that could potentially infect people and animals. This early detection allows us the increase our control efforts and public outreach to prevent the human infections. The AVMVCD utilizes 10 flocks throughout the district.
Several bird species die after being infected with WNV and can therefore serve as another early warning system. The California Department of Public Health coordinates a statewide surveillance of dead birds. They can be reported online. District personnel will pick up the birds and send them to the State lab if they qualify for testing – they have to be intact and dead less than 24 hours.
If birds are not picked up by the end of the day you can safely dispose of them in the garbage.
These are stationary traps that are strategically placed in 16 locations in the district from early April through October. They capture mosquitoes and other insects by attracting them with light and then sucking them into a jar with a fan. They are collected once a week and the mosquitoes are identified and counted to track population density in those areas. Since these mosquitoes are dead when picked up they cannot be used for virus detection.
The encephalitis vector surveillance (EVS) traps use dry ice (CO2) as a bait to attract host-seeking female mosquitoes. EVS traps are used mainly to determine whether SLE, WEE or WNV occurs within a localized area. During mosquito season, traps are set overnight once a week at variable locations throughout the District to capture mosquitoes. These live mosquitoes are identified, counted and then sent to the California Department of Public Health (CDPH) to be tested for SLE, WEE, and WNV.
Although there are only occasional cases of malaria and dengue fever in the United States, mosquitoes here can still cause illness and death in people and animals. Some of the mosquito-borne diseases we are concerned with are
Newly approaching diseases are
There are about 2,500 different species of mosquitoes worldwide, 53 species in California and 10 species in the Antelope Valley. The "house mosquito" (Culex quinquefasciatus) and the "encephalitis mosquito" (Culex tarsalis) are the most common species in the Antelope Valley. They are both capable of transmitting West Nile Virus to animals and humans.
California has one of the most extensive mosquito surveillance systems in the entire Nation. This is due to the cooperation of the California Department of Public Health (CDPH), California Food and Agriculture, the University of California, and the Mosquito and Vector Control Association of California (MVCAC).
The MVCAC is made up of over 60 special districts and local public health agencies throughout California to provide quality public information, comprehensive mosquito and vector-borne disease surveillance, training to high professional standards, and effective legislative advocacy on behalf of California mosquito and vector control districts.
The Antelope Valley Mosquito & Vector Control District conducts surveillance to identify increased mosquito activity as well as an early detection system for mosquito-borne diseases. The diseases that we routinely check for are St. Louis Encephalitis (SLE), Western Equine Encephalomyelitis (WEE), and West Nile Virus (WNV). We utilize three different types of mosquito traps and ten chicken coops with sentinel chickens throughout the district.