Repellent Compounds Used for Protection From Ticks and Their Toxicological Evaluation

Ticks are vectors of very harmful diseases in humans and animals. Nine arbovirus, two rickettsia, two protozoa and one helminthic diseases are transmitted by ticks in different climatic and geographical zones. Twenty six tick species have been determined in Turkey until now. These tick species transmit tropical theileriosis and babesiosis, which are cause of important economical loses especially in farm animals, and lyme disease and Crimean-Congo Hemorrhagic Fever in humans. The control of ticks is getting more important due to appearance of Crimean-Congo Hemorrhagic Fewer (CCHF) in Turkey in recent years. However, the control of ticks is a very difficult and expensive procedure and generally chance of success is very low. The main aims of tick control are acaricidal control of ticks on animals, making different applications for elimination of tick-born diseases in humans and reduction of the contact risk between humans, domestic animals and ticks. The repellent is a common name of the compounds, which are applied on directly skin, clothes and sometimes curtains and nets, and prevent the humans and domestic animals against attacks of harmful organisms such as mosquitoes, flies and ticks. Although repellent compounds are applied for the organisms which annoy and suck blood at outdoor, some products used in indoor areas (houses, offices and animal shelters), such as mosquito nets, coils and thermal vaporised liquid and mat formulations, are also evaluated in this frame. Repellents are very beneficial products for prevent attack by ticks. But, it should be known that these compounds are not completely harmless and sometimes they can cause toxic effects in humans and domestic animals. In this review, definition and history of the repellent compounds, the action mechanisms and features of an ideal repellent, important repellent compounds and their toxicological importance and safety usage principles of repellents were evaluated.