Mites and Ticks

The Acari are the smallest chelicerates but are also the most numerous world-wide in terms of the number of species. They are commonly known as mites and ticks. Adults have four pairs of legs while the young have three pairs. They include both parasites and predators which generally live on other animals or inside plants, although some inhabit the soil.

Tick bites can be painful and irritating, and severe cases of multiple tick infestation in a single animal, can result in anaemia, toxic reaction and paralysis. However, it is the tick's potential as a vector of pathogenic diseases that is more serious. Although man is only an incidental host and their natural hosts are wild animals, some of the tick species present in Arabia can transmit human diseases. Many potentially infected ticks are accidentally imported along with foreign livestock but are equally able to feed on local livestock and could establish permanent populations. If they are infected with agents pathogenic to humans or domestic animals these may also be spread by local ticks. Although cases of tick-borne human disease are rare there is an element of risk.

Ticks from the UAE
There are no published records of ticks for the Emirates but the following species are native to Arabia (Hoogstraal et al, 1984) and therefore likely to be part of the local tick fauna. Hyalomma hyalomma anatolicum anatolicum is very common and its hosts include domestic stock, lizards, rodents, hedgehogs, hares and humans. It is the major vector of Crimean-Congo Haemorrhagic Fever (CCHF) in the Southern Soviet republics, Pakistan and Nigeria. Other common Hyalomma ticks include H.h.dromedarii which is both a vector for CCHF and a natural reservoir of Q-fever; and H.h.impeltatum and H.h.marginatum turcanicum which have also been implicated as vectors for CCHF. The kennel or brown dog tick, Rhipicephalus rhipicephalus sanguineus , generally feeds on dogs as its name suggests, but can carry CCHF as can the closely related R.r.turanicus . Another vector of CCHF is Boophilus annulatus although its preferred hosts are goats. Human cases of CCHF are very rare in the Emirates, but it has been reported from Dubai.