A new high-performance PCR diagnostic for the detection of pyrethroid knockdown resistance kdr in Anopheles gambiae.

Monitoring the spread of the knockdown resistance allele kdr in areas of extensive pyrethroid use is critical to vector-control projects. Currently available methods for detecting kdr from DNA samples are characterized by poor amplification, time-consuming steps, and primers that exhibit frequent null alleles. We describe a new PCR diagnostic that uses fluorescent primers based on conserved priming sites and enables simple detection of the kdr allele on a sequencer. Using samples from a West African Anopheles gambiae population, we show that the new PCR yielded significantly higher rates of amplification and more accurate estimates of kdr frequency. The method works equally well for the leucine to phenylalanine substitution found in West Africa and the East African leucine to serine substitution.