piperidines and Tick-Infestations

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.

Topics: Administration, Topical; Adult; Animals; DEET; Humans; Insect Repellents; Ixodidae; Piperidines; Tick Infestations; Time Factors; White People

In a series of field trials 48 (55%) of 88 field cases of East Coast fever treated with halofuginone lactate recovered and survived and 40 (45%) died while 31 (86%) of 36 untreated control animals died of East Coast fever and five (14%) recovered. For cases diagnosed and treated early a 100% recovery rate was achieved. A single dose at 1.2 mg/kg body weight per os was adequate. Recovery rate was only 36% for cases diagnosed and treated at an advanced stage. Such cases required two doses at 1.2 mg/kg or a combination of 1.2 and 2.4 mg/kg body weight given at about two days interval. The temperature dropped to normal levels within 48 h of treatment and schizonts started degenerating as early as 24 h after treatment and had disappeared by 48 to 72 h. Piroplasms were not affected by the drug. Recovered animals remained free of East Coast fever for periods up to 12 months of observation despite continuous tick challenge. It was concluded that, with early detection and treatment augmented with proper tick control, outbreaks of East Coast fever can be effectively controlled with halofuginone lactate.

Topics: Animals; Cattle; Piperidines; Quinazolines; Quinazolinones; Theileriasis; Tick Infestations