odor-baited trap

Ninety years ago it was discovered that mosquitoes track us down at night by responding to the smell we as humans produce. Since then, many studies have focused on identifying the nature of the chemicals we produce with the aim to use them to lure mosquitoes to trapping devices, thereby interrupting bloodfeeding and thus transmission of diseases like malaria. But why is there still no trap available for use in the developing world where malaria hits hardest?