19 - Antibody responses against salivary proteins of Ae. albopictus and Cx. quinquefasciatus in Northern Cardinals in Louisiana

West Nile virus (WNV) is a mosquito-borne pathogen primarily transmitted by Culex mosquitoes. Since the emergence of WNV in the US in 1999, detecting infection in birds and mosquitoes have become the primary surveillance tools used as precursors for human infection and neuroinvasive disease incidence. WNV is normally transmitted between birds and mosquitoes in the environment; and humans are considered dead end hosts. WNV is transmitted to a vertebrate host through the bite of an infected mosquito during blood feeding. In this process, mosquitoes deposit salivary proteins that elicit antibody responses; previous studies have established that the concentration of such antibodies is directly related to the intensity of exposure to mosquito bites and a good proxy to determine risk of infection in the human population. Since WNV infection in birds has also been used to determine risk of transmission in some areas, we tested the levels of IgY antibodies against whole salivary glands of Ae. albopictus and Cx. quinquefaciatus in more than 700 Northern Cardinals captured via mist nets in Louisiana between 2018 and 2019. Our preliminary data (n=169) showed a significant negative correlation between the sample collection date and the IgY antibody levels against Ae. albopictus in younger hatch year Northern Cardinals (p=0.0375). This correlation was not shown in older after hatch year birds. We did not find significant difference in the antibody levels between males or females from any of the locations. In general, higher levels of antibodies against Ae. albopictus were observed in comparison to Cx. quinquefasciatus. We will discuss the proteins that were identified by immunoblot as the most immunogenic in these two different sets of samples. We are working towards designing new tools to track bird exposure to infective bites to effectively measure risk of WNV transmission.