Converting Mosquito Surveillance to Arbovirus Surveillance with Honey-Baited Nucleic Acid Preservation Cards

Abstract

Spatially and temporally accurate information about infectious mosquito distribution allows for pre-emptive public health interventions that can reduce the burden of mosquito-borne infections on human populations. However, the labile nature of arboviruses, the low prevalence of infection in mosquitoes, the expensive labor costs for mosquito identification and sorting, and the specialized equipment required for arbovirus testing can obstruct arbovirus surveillance efforts. The recently developed techniques of testing mosquito expectorate using honey-baited nucleic acid preservation cards or sugar bait stations allows a sensitive method of testing for infectious, rather than infected, mosquito vectors. Here we report the results from the first large-scale incorporation of honey-baited cards into an existing mosquito surveillance program. During 4 months of the peak virus season (January-April, 2014) for a total of 577 trap nights, we set CO2-baited encephalitis vector survey (EVS) light traps at 88 locations in South Australia. The collection container for the EVS trap was modified to allow for the placement of a honey-baited nucleic acid preservation card (FTA™ card) inside. After collection, mosquitoes were maintained in a humid environment and allowed access to the cards for 1 week. Cards were then analyzed for common endemic Australian arboviruses using a nested RT-PCR. Eighteen virus detections, including 11 Ross River virus, four Barmah Forest virus, and three Stratford virus (not previously reported from South Australia) were obtained. Our findings suggest that adding FTA cards to an existing mosquito surveillance program is a rapid and efficient way of detecting infectious mosquitoes with high spatial resolution.

Improving public health intervention for mosquito-borne disease: the value of geovisualization using source of infection and LandScan data

“…This finding is supported by studies across Australia which have found that RRV infection rates (human and mosquito) vary at a relatively small scale [4,[35][36][37]. The fine-scale variation in disease rates we see here could be due to variation in reporting/testing by medical practitioners, behavioural differences of the patients or could represent variation in transmission ecology [19,34]; potentially all three factors are influencing disease rates to some degree. The fine-scale variation in disease rates we see here could be due to variation in reporting/testing by medical practitioners, behavioural differences of the patients or could represent variation in transmission ecology [19,34]; potentially all three factors are influencing disease rates to some degree.…”

A systematic review of FTA cards® as a tool for viral RNA preservation in fieldwork: Are they safe and effective?

“…Plant samples were assessed in 31.9% of the included articles, and samples obtained from insects corresponded to 14.9%. These works aimed to amplify viral RNA of arboviruses that can cause disease in humans, and also viruses capable of causing disease in fishes and plants (Hall-Mendelin et al, 2010;Price et al, 2014;Flies et al, 2015;Yang et al, 2015;Navaneeth Krishnan et al, 2016;Hall-Mendelin et al, 2017;Melanson et al, 2017;Chikh-Ali et al, 2016). Viral specimens were derived from cell culture or from a commercial inactivated vaccine in 10.6% of the reports (Muthukrishnan et al, 2008;Li et al, 2012;Bankamp et al, 2013;Sakai et al, 2015;Montmayeur et al, 2017).…”

“…This challenge is particularly relevant in settings where proper technical support for RNA handling may not be available (hereafter referred to as fieldwork). Although some studies have evaluated the FTA® cards for viral RNA preservation (Ndunguru et al, 2005;Muthukrishnan et al, 2008;Flies et al, 2015), the optimal conditions for their handling have not been extensively studied. Notwithstanding, it is crucial to determine the appropriate temperature and maximum time for storing RNA samples on FTA cards, as well as their biosafety, in order to fieldwork with these pathogens.…”

Zika virus replication in the mosquitoCulex quinquefasciatusin Brazil

“…We found that after 11 dpi, most samples were negative for ZIKV (apart from one positive salivary gland of A. aegypti given 10 To confirm that the virus detected in the salivary glands by RT-qPCR was being released in saliva during consecutive blood meals, we followed up the viral load from days 8 to 14 postinfection using filter paper cards. This strategy of viral RNA detection directly from FTA cards has been employed in previous studies for arbovirus surveillance (16,17). In the present study, we successfully detected ZIKV RNA copies in cards from A. aegypti and C.…”