Arthropods vectors of diseases. What is the risk for travellers of being bitten? Of being contaminated?

Many bloodsucking arthropods are potential vectors of disease. To become a vector, the arthropod must be susceptible to the infective agent and must s urvive the incubation period so as to transmit the pathogens to a host. Whi le some arthropod associated diseases affect only man (e.g. malaria) most o f these diseases are (anthropo-) zoonoses with man often an accidental host The risk of contamination depends on the one hand on the biting behaviour of the vector; its biology and distribution, and on the other hand on the s ites visited by the traveller, the length of his stay, his activities, the conditions of sleeping accommodation. The risk of contracting malaria is ve ry high in tropical Africa, in me forest area of South America and South Ea st Asia, in Papua New Guinea. Malaria can be prevented ii measures (e.g. py rethroid impregnated bed nets, repellents) are taken to avoid bites of Anop heline mosquitoes between sunset and sunrise, but appropriate chemoprophyla xis must not be neglected. Lethal cases of yellow fever among unvaccinated travellers still occur despite a strict international regulation on vaccina tion requirements. Dengue is a major health problem in intertropical areas. As no vaccine is available, personal protection measures are recommended a gainst daytime-biting mosquitoes, including the use of protective clothing, repellents. Other arthropod borne diseases among travellers are less commo n but the risks increase during adventure trips (e.g, zoonotic leishmaniasi s, tick-borne relapsing fever) and humanitarian actions (e.g. risk of louse -borne typhus during visits of overcrowded prisons). Tick-borne diseases receive nowadays more attention. These diseases are not only restricted to some occupations (farmers, veterinarians) but also ramb lers and campers are at risk. Attached licks should be removed rapidly and carefully, since several hours of attachment are needed for transmission of spirochetes of LYME disease.