Medical and Veterinary Acarology

Abstract

More than 250 species of mites are recognized as the cause of health-related problems for humans and domestic animals. Types of problems include temporary irritation of the skin due to bites or feeding on host skin, fur or feathers; persistent dermatitis; mite-induced allergies; transmission of pathogenic microbial agents; and invasions of respiratory passages, ear canals and occasionally internal organs. Chicken mite (Dermanyssus gallinae) is considered as one of the most serious pests of poultry birds and may also serve as vectors for diseases such as ‘salmonellosis’ and avian ‘spirochaetosis’. Mite feeding in poultry birds results in pain, irritation, restlessness and decreased egg production. Straw itch mite (Pyemotes ventricosus), chiggers (Eutrombicula alfredugesi) and burrowing mites (Sarcoptes spp., Notoedres spp. and Knemidocoptes spp.) are other important parasitic mites. Non-burrowing mites (Psoroptes spp., Chorioptes spp. and Otodectes spp.) also have great economic importance as parasites of veterinary animals. Nasal mites, belonging to families Halarachnidae and Macronyssidae, infest nasal cavity of dogs and snakes. House dust mites (Dermatophagoides farinae and D. pteronyssinus) live in association with man and are responsible for house dust mite allergy. Places with damper climates are more favoured by mites than dry ones. Ticks are exclusively bloodsucking ectoparasites and disperse pathogenic organisms including protozoan, viral, bacterial and even fungal pathogens. Tick-borne diseases of livestock include babesiosis, theileriosis, tularaemia, Lyme disease and Rocky Mountain fever.