Risk factors of exposure to Aedes albopictus bites in mainland France using an immunological biomarker.

In recent decades, the invasive Aedes albopictus vector has spread across Europe and is responsible for numerous outbreaks of autochthonous arboviral disease. The aim of this study was to identify epidemiological and sociological risk factors related to individual levels of exposure to Aedes albopictus bites. A multidisciplinary survey was conducted with volunteer blood donors living in areas either colonised or not by Aedes albopictus in mainland France. Individual levels of exposure were evaluated by measuring the IgG level specific to Aedes albopictus saliva. The most striking risk factors concerned the localisation and characteristics of the dwelling. Individuals living in areas colonised prior to 2009 or recently colonised (between 2010 and 2012) had higher anti-salivary gland extract IgG levels compared with those who were living in areas not yet colonised by Ae. albopictus. The type of dwelling did not seem to impact the level of exposure to Aedes bites. People living in apartments had a higher anti-salivary gland extract IgG level than those living in individual houses but the difference was not statistically significant. Interestingly, the presence of air conditioning or window nets was associated with a noticeable reduction in bite intensity.

Improved accuracy of the transcriptional profiling method of age grading in Aedes aegypti mosquitoes under laboratory and semi-field cage conditions and in the presence of Wolbachia infection.

Transcriptional profiling is an effective method of predicting age in the mosquito Aedes aegypti in the laboratory, however, its effectiveness is limited to younger mosquitoes. To address this we used a microarray to identify new gene candidates that show significant expression changes in older mosquitoes. These genes were then used to create a revised model, which upon evaluation in both laboratory and semi-field conditions, proved to have improved accuracy overall and for older mosquitoes. In association with the development of symbiont-based control strategies for Ae. aegypti, we also tested the model's accuracy for Wolbachia-infected mosquitoes and found no decline in performance. Our findings suggest that the new model is a robust and powerful tool for age determination in Australian Ae. aegypti populations.