Repellent efficacy of DEET and KBR 3023 against Amblyomma hebraeum (Acari: Ixodidae).
The bont tick, Amblyomma hebraeum Koch, is the principal vector of Rickettsia africae, the agent of African tick bite fever, in southern Africa. In contrast to most other hard ticks, members of the genus Amblyomma exhibit a characteristic attack host-seeking behavior. The efficacy of topically applied 20% lotions of DEET (diethyl-3-methylbenzamide), the currently considered reference repellent substance, and KBR 3023, a recently developed piperidine compound, was evaluated against laboratory-reared A. hebraeum nymphs on treated fingers. Both substances repelled >85% of nymph attacks at 0 and 1 h postapplication. At 2, 3, and 4 h, the repellent efficacies of DEET were 84%, 68% and 71%, whereas those of KBR 3023 were 56, 55, and 54%. The observed differences between the two test substances were statistically significant only at 2 h postapplication. This first study of topical repellents against A. hebraeum suggests that 20% lotions of DEET and KBR 3023 are effective for 2 and 1 h, respectively, but that the repellent efficacies decrease thereafter.
Pretorius
Anne-Marié
AM
Department of Medical Microbiology, Faculty of Health Sciences, University of the Free State, Bloemfontein, South Africa. gnvramp@med.uovs.ac.za
Jensenius
Mogens
M
Clarke
Francoise
F
Ringertz
Signe Holta
SH
D000287:Administration, Topical; D000328:Adult; D000818:Animals; D003671:DEET / Q000008:administration & dosage / Q000633:toxicity*; D006801:Humans; D007302:Insect Repellents / Q000008:administration & dosage / Q000633:toxicity*; D026863:Ixodidae / Q000502:physiology*; D010880:Piperidines / Q000008:administration & dosage / Q000633:toxicity*; D013984:Tick Infestations / Q000517:prevention & control*; D013997:Time Factors; D044465:White People
D007302:Insect Repellents; D010880:Piperidines; D003671:DEET; C483506:picaridin