Abstract:
Rift Valley fever (RVF), a mosquito-borne zoonosis, is a major public health and veterinary problem in sub-Saharan Africa.
Surveillance to monitor mosquito populations during the inter-epidemic period (IEP) and viral activity in these vectors is
critical to informing public health decisions for early warning and control of the disease. Using a combination of field
bioassays, electrophysiological and chemical analyses we demonstrated that skin-derived aldehydes (heptanal, octanal,
nonanal, decanal) common to RVF virus (RVFV) hosts including sheep, cow, donkey, goat and human serve as potent
attractants for RVFV mosquito vectors. Furthermore, a blend formulated from the four aldehydes and combined with CO2-
baited CDC trap without a light bulb doubled to tripled trap captures compared to control traps baited with CO2 alone. Our
results reveal that (a) because of the commonality of the host chemical signature required for attraction, the host-vector
interaction appears to favor the mosquito vector allowing it to find and opportunistically feed on a wide range of
mammalian hosts of the disease, and (b) the sensitivity, specificity and superiority of this trapping system offers the
potential for its wider use in surveillance programs for RVFV mosquito vectors especially during the IEP.
