Dr. Murai Éva szerk.: Parasitologia Hungarica 24. (Budapest, 1991)

In an experimental animal model, Piesman et al. found that when infected ticks were removed within 24 hours after attachment, the risk of borrelia transmission was very low, while 72 hours later it reached 100% (119). Although nymphs are seldom infected, because of their tiny size they play an important role in borrelia transmission (93). Prevention Wearing closed clothes is frequently recommended for personal prophylaxis. To take this advice is almost impossible in hot weather, and its benefit is also questionable. Ticks seldom if ever bite on the naked parts of the body. They do not like climbing up trees and never throw themselves on the victim but can easily be collected from grass and bushes. Ticks are encountered on well-maintained lawns as frequently as in forests. Personal protection. Repellents applied to clothing including the insides of trouser cuffs and socks prevent tick bite. Permethrin has been shown to provide excellent protection from tick bites. There are also repellents that do not kill ticks when impregnated into clothing such as N,N-diethyl-m-tolumide ("SZUKU", "Protect B"). The taping of trouser cuffs and tucking them in the footwear prevent ticks from easily crawling onto the untreated skin inside the clothing. Ticks are more easily observed on light- than on dark-coloured clothing. Repellents applied to the skin may help prevent the attachment of ticks but their effectiveness is lost within a few hours after application. Tick attachment and removal Ticks attach to their hosts by piercing the skin and inserting the hypostome with its recurved denticles. A cement-like protein mixture, which is secreted by the tick, and the anchoring hypostome hold the tick firmly in position. Ticks may be removed by grasping them as close to the skin as possible with a pair of forceps or tweezers. A steady upward pressure is exerted to detach the tick from the skin. An antiseptic may be applied onto the skin. Humans visiting tick-infested areas should periodically and thoroughly inspect their body and promptly remove ticks. Nymphs feed on their hosts for 4-7 days and adults for 8-11 days. Ticks are most likely to transmit spirochetes after they have fed for more than 48 hours. Prompt removal of ticks clearly diminishes the risk of infection. Ticks to be removed should never be greased with petrol, paraffin, body milk or any other chemical. During removal one should keep in mind that the tick's gut may be filled with borrelia. Any technique that may cause regurgitation can be dangerous. Eradication of ticks would be more effective than personal protection. Although drastic methods have been applied, their effect remained transient (132). A method of lasting effect and safe the environment has been developed by Mather et al. (99).