Middle East DVEP - Armed Forces Pest Management Board

on camels, pigs, dogs, donkeys, humans, house rats, and grass rats. Humans are not apreferred host. Ornithodoros savignyi is frequently encountered along trails or in theshelter of trees at oases. It feeds on camels and goats but may feed on humans.Ornithodoros tholozani is usually found in caves, huts, cabins, or stables. It feeds oncamels, sheep and, less frequently, on man.Adult Ornithodoros spp. ticks feed at night, usually for only 1 to 2 hours. Nymphs andadults feed quickly and usually painlessly, so their bites may go undetected by the humanhost until well after the tick has detached. Depending on species, larvae may bequiescent and nonfeeding or may attach to a host for several days. Subsequent nymphalstages are active and feed on blood. Engorgement is rapid, and these ticks drop off theirhosts after feeding. After 2 to 8 molts (generally 3 to 4), adults emerge and mate. Thefemale mates after feeding and then begins to lay eggs. Females may live many yearswithout a bloodmeal, but blood is required for egg development. The number of eggsdeposited may total several hundred over the life span of the female, with up to 8 batchesof eggs produced. Vector ecology profiles of ticks of the Middle East are summarized inAppendix B.2.Vector Surveillance and Suppression. Argasid ticks such as Ornithodoros are found inthe restricted habitats of their hosts and rarely move very far. They can be found inloose, dried soil of dwellings, cracks and crevices in mud-walled animal shelters, animalburrows and animal resting places, and under tree bark. They can be collected by passingsoil through a metal sieve or by blowing a flushing agent into cracks and crevices andother hiding places. Some species are attracted by carbon dioxide, and dry ice can beused in the collection of burrow-dwelling ticks. Ornithodorine ticks fluoresce brightlyunder ultraviolet light. There is little seasonal fluctuation in numbers of argasids sincetheir microhabitats are relatively stable. Personal protective measures discussed inTIM 36 are the most important means of preventing tick bites and diseases transmitted bysoft ticks. Tents and bedding can be treated with the repellent permethrin. Encampmentsshould not be established in areas infested with Ornithodoros ticks. Troops should avoidusing indigenous shelters, caves, or old bunkers for bivouac sites or recreationalpurposes. Control of small mammals around cantonments can eliminate potential vectorhosts. Rodent-proofing structures to prevent colonization by rodents and their soft ticksis an important preventive measure. Limited area application of appropriate acaricides,especially in rodent burrows, can reduce soft tick populations.Medical personnel may elect to administer antibiotic chemoprophylaxis after exposure totick bites when risk of acquiring infection is high. See Appendix F for personalprotective measures.G. Crimean-Congo Hemorrhagic Fever (CCHF).CCHF is a zoonotic disease caused by a tick-borne virus of the family Bunyaviridae. Thedisease is characterized by febrile illness with headache, muscle pain and rash, frequentlyfollowed by a hemorrhagic state with hepatitis. The mortality rate can exceed 30%. Theincubation period ranges from 3 to 10 days. CCHF may be confused clinically with otherhemorrhagic infectious diseases.84