Blog post by Jo Ohm
The past year has seen a number of clever new methods to detect infection in mosquito vectors. These new methods which allow for improved detection and monitoring of the time course of infections inside mosquitoes will be powerful tools for exploring many questions central to the research of VectorBiters. If inventions fuel science and science fuels invention, the future of vector-borne disease research has exciting findings to come from the use of these new tools. Below are some of the latest methods published in the literature which promise to improve our understanding of vector-borne disease transmission:
- Detection of virus in mosquitoes using Near Infrared Spectroscopy (NIRS) – NIRS has already been demonstrated to be useful in ageing mosquitoes and identifying between Anopheles species and a recent paper in Science Advances suggests it can be used to detect Zika-infected mosquitoes. Pluses: 18x faster and 110x cheaper than using RT-qPCR for Zika detection ; Minuses: destructive sampling, requires highly sensitive microspectrometer, unknown if it will work with field samples
- Malaria sporozoites measured through sugar feeding – A Nature Scientific Reports paper published earlier this month reports a nondestructive way to detect when malaria-infected mosquitoes become infectious by using PCR to detect parasites left behind in sugar-soaked cotton or FTA cards. This method is similar to methods already developed to detect dengue from mosquito sugar water. Pluses: Nondestructive sample, possible to use on individual mosquitoes (?) ; Minuses: Feeding on sugar through FTA cards reduces survival compared to feeding on sugar through cotton
- Identifying Aedes species and Wolbachia-infection status with a cellphone – Recently on bioRxiv, Bhadra et al report detection of Wolbachia-infected mosquitoes using an assay that fluoresces in response to the presence of Wolbachia-specific nucleic acids, which should be useful for surveillance purposes following Wolbachia-based mosquito field releases. Pluses: No DNA extractions required, likely to work in field settings ; Minuses: ?
- Track mosquitoes using rhodamine b – Mosquito mark-recapture experiments are notoriously difficult and marking with fluorescent dies can have fitness costs on the mosquitoes being marked. A new way to mark mosquitoes using rhodamine b fed through a honey solution was reported to have no detectable fitness costs on marked males. This should be a useful tool for capturing dispersal distance, mating patterns, and age of wild mosquito populations. Pluses: No fitness costs for marking mosquitoes for a mark-recapture experiment and the dye transfers to females through the seminal fluids of marked males ; Minuses: Only demonstrated in males so far, probably works for females (?)
New and exciting technologies have been developed to improve our approach to detecting and monitoring infectious mosquitoes. What other methods are out there? What methods don’t exist yet that would improve our understanding of vectors and vector-borne disease? Have any VectorBiters tried any of these methods yet?