Estimating Contact Rates Between -Exposed Males With Female .

INTRODUCTION

Effective control of will reduce the frequency and severity of outbreaks of dengue, chikungunya, and Zika; however, control programs are increasingly threatened by the rapid development of insecticide resistance. Thus, there is an urgent need for novel vector control tools, such as auto-dissemination of the entomopathogenic fungi and The aim of this study was to estimate contact rates of -exposed males with wild female . As a control the contact rates of untreated males with wild females was contrasted.

METHODS

The study was conducted in Reynosa, Mexico. The treatment and control households (n = 15 per group) were geographically separated by an arid and hot area that naturally prevented the flight of males between arms. In each control household, 40 -exposed male were released per week for 8 weeks (specimens were exposed to a concentration of 5.96 × 10 conidia/cm for 24 h; n = 4,800 males). In each control household, 40 untreated males were released per week for 8 weeks (n = 4,800 males). All specimens were dust-marked prior to release. Mosquito abundance was monitored with human landing collections, and captured were examined for any dust-marking.

RESULTS

In the treatment households, the contact rate of females with marked, fungus-treated males was 14% (n = 29 females marked from 197). Where in the control households, the contact rate of females with marked, untreated males was only 6% (n = 22 marked from 365). In the treatment households the recapture rate of released males was at 5% and higher than that for the control households (which was 2%). Auto-dissemination of from infected males to female was demonstrated through the recovery of an infected female from the floor of a household.

CONCLUSIONS

Overall, the contact rate between -infected males with the natural female population was 60% higher than for the control group of healthy males. The results provide further support to the release of fungus-exposed males as a potentially useful strategy against , though further research is required.