Ornithonyssus bacoti | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Chelicerata |
Class: | Arachnida |
Order: | Mesostigmata |
Family: | Macronyssidae |
Genus: | Ornithonyssus |
Species: | O. bacoti |
Binomial name | |
Ornithonyssus bacoti (Hirst, 1913) | |
Ornithonyssus bacoti (also known as the tropical rat mite and formerly called Liponyssus bacoti) is a hematophagous parasite. [1] It feeds on blood and serum from many hosts. [2] [3] O. bacoti can be found and cause disease on rats and wild rodents most commonly, but also small mammals and humans when other hosts are scarce. [3] [4] Outbreaks tend to occur in older, less maintained buildings. The mite, however, can travel several hundred feet on its own if necessary to find a host and can survive for extended periods of time without a host. This, along with the nonspecific dermatitis it causes, can prevent accurate and fast diagnosis of rat mite dermatitis. The scarcity of reports, due in part to misdiagnosis and also the mildness of its symptoms, makes the disease seem less common than it is. The tropical rat mite can be found in both temperate and tropical regions or rather all continents except the Arctic and Antarctic. [3]
The tropical rat mite was first reported in Australia in 1913 in a human case report. [5] In 1923, the United States identified it as a cause of dermatitis in humans. In 1931, it was discovered in Hamburg, Germany, in a seaport. [2] [1]
The tropical rat mite is between 0.75 and 1.44 mm in length and is unsegmented with chelicerae or mandibles which are suited to piercing. [4] [3] They have a sharp caudal apex of the scutum, an oval genital shield, and a cranially positioned anus. [2] These mites are capable of parthenogenic reproduction. [6] After taking a blood meal, they are static and yellow or dark red in color. However, before a blood meal, they are more active and grey in color. [3]
Ornithonyssus bacoti has five lifestages: egg, larva, protonymph, deutonymph, and adult. The only two stages that feed are the protonymph and the adult. [4] [3] Once they have fed, they either drop off the host to molt or lay up to a 100 eggs. An egg takes one and a half days to hatch into a larva, which then attaches to a host and takes one to two days to molt into a protonymph. A protonymph then molts into an adult. The whole lifeycle takes 7 to 16 days to complete. A minimum of 13 days is needed to go from egg to egg. [4] The larva is the only stage that has three pairs of legs as opposed to four pairs. [6]
When the tropical rat mite bites its host, it causes an inflammatory reaction to its saliva and then pruritic nonspecific dermatitis, known as rat mite dermatitis. Welts may persist for weeks in some individuals. [3] In children especially, vesicular or eczematous reactions sometimes occur. Secondary excoriations due to scratching are common. [3] Papular urticaria has been suggested as developing in some people. [6]
No human disease has been definitively found to be naturally vectored by this mite. Lab demonstrations have proved that the mite is at least capable of vectoring murine typhus, rickettsialpox, tularemia, plague, coxsackievirus, and Q fever, although it has not been known to do so outside the lab. [3] The mite was reported as capable of vectoring human typhus, but these reports are not generally accepted. [6]
The bites tend to be grouped together due to the piecemeal feeding behavior of these mites. [6] [3] They can occur anywhere on the body though commonly on the neck, head, extremities, abdomen and chest. The papules are generally 1 to 4 mm in diameter and sometimes vesicles appear. [6] [4] The symptoms of this disease are common or at least mistakable for many things that should be checked for as well in differential diagnosis such as prurigo simplex, allergies, mosquito or other insect bites, bacterial folliculitis, dermatitis herpetiformis, scabies, and pediculosis. [2] [4] [3] Identification of the mite itself is required for definitive diagnosis. This can be collected by laying cellophane tape or "Sticky cards" (cardboard cards with a glue surface) in the area believed to be infested with the mite. [3]
A biopsy of the lesions only shows superficial and mid-dermal perivascular infiltrates and occasionally eosinophils. This method is so nonspecific as to be inconclusive in diagnosis. [6]
Treatment of rat mite dermatitis is on a symptomatic basis. Generally, an oral antihistamine, a topical corticosteroid, gamma benzene hexachloride, benzyl benzoate, or crotamiton is used to provide relief. [6] [4] [2] [1] Some patients however require no treatment. [6] Bug sprays containing DEET can help prevent bites during an active infestation. [7] To effectively rid the patient of dermatitis thorough eradication of the mite from pets and their environment is crucial. Acarides for the environment might be hydrocyanic acid, chlorophenothane (DDT), chlordane, permethrin, pyriproxyfen, or lindane. [2] [3] [4] Pet rats are a natural host for mites, but other small mammals kept as pets (mice, hamsters, rabbits, guinea pigs, etc.) may also suffer infestation. To rid pets of the mite, selamectin is generally used in the form of Revolution, Stronghold or Pfizer. [2] Extermination of rats and other wild rodents which are common hosts is also key. Several weeks are needed to be sure that a proper eradication of these mites is complete because the mites are not only found mostly in the environment of the host instead of on the host itself, but also have been found to survive up to 63 days without a blood meal. [3]
Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus Rattus. Other rat genera include Neotoma, Bandicota and Dipodomys.
Flea, the common name for the order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by ingesting the blood of their hosts. Adult fleas grow to about 3 millimetres long, are usually brown, and have bodies that are "flattened" sideways or narrow, enabling them to move through their hosts' fur or feathers. They lack wings; their hind legs are extremely well adapted for jumping. Their claws keep them from being dislodged, and their mouthparts are adapted for piercing skin and sucking blood. They can leap 50 times their body length, a feat second only to jumps made by another group of insects, the superfamily of froghoppers. Flea larvae are worm-like, with no limbs; they have chewing mouthparts and feed on organic debris left on their hosts' skin.
Cimex lectularius is a species of Cimicidae. Its primary hosts are humans, and it is one of the world's major "nuisance pests".
Rat-bite fever (RBF) is an acute, febrile human illness caused by bacteria transmitted by rodents, in most cases, which is passed from rodent to human by the rodent's urine or mucous secretions. Alternative names for rat-bite fever include streptobacillary fever, streptobacillosis, spirillary fever, bogger, and epidemic arthritic erythema. It is a rare disease spread by infected rodents and caused by two specific types of bacteria:
Acariasis is an infestation with mites.
Ixodes holocyclus, commonly known as the Australian paralysis tick, is one of about 75 species in the Australian tick fauna and is considered the most medically important. It can cause paralysis by injecting neurotoxins into its host. It is usually found in a 20-kilometre wide band following the eastern coastline of Australia. Within this range Ixodes holocyclus is the tick most frequently encountered by humans and their pets. As this area also contains Australia's most densely populated regions, bites on people, pets and livestock are relatively common.
The Oriental rat flea, also known as the tropical rat flea or the rat flea, is a parasite of rodents, primarily of the genus Rattus, and is a primary vector for bubonic plague and murine typhus. This occurs when a flea that has fed on an infected rodent bites a human, although this flea can live on any warm blooded mammal.
The cat flea is an extremely common parasitic insect whose principal host is the domestic cat, although a high proportion of the fleas found on dogs also belong to this species. This is despite the widespread existence of a separate and well-established "dog" flea, Ctenocephalides canis. Cat fleas originated in Africa but can now be found globally. As humans began domesticating cats, the prevalence of the cat flea increased and it spread throughout the world.
Dermanyssus gallinae is a haematophagous ectoparasite of poultry. It has been implicated as a vector of several major pathogenic diseases. Despite its common names, it has a wide range of hosts including several species of wild birds and mammals, including humans, where the condition it causes is called gamasoidosis. In both size and appearance, it resembles the northern fowl mite, Ornithonyssus sylviarum.
Amblyomma americanum, also known as the lone star tick, the northeastern water tick, or the turkey tick, is a type of tick indigenous to much of the eastern United States and Mexico, that bites painlessly and commonly goes unnoticed, remaining attached to its host for as long as seven days until it is fully engorged with blood. It is a member of the phylum Arthropoda, class Arachnida. The adult lone star tick is sexually dimorphic, named for a silvery-white, star-shaped spot or "lone star" present near the center of the posterior portion of the adult female shield (scutum); adult males conversely have varied white streaks or spots around the margins of their shields.
The human flea – once also called the house flea – is a cosmopolitan flea species that has, in spite of the common name, a wide host spectrum. It is one of six species in the genus Pulex; the other five are all confined to the Nearctic and Neotropical realms. The species is thought to have originated in South America, where its original host may have been the guinea pig or peccary.
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Gamasoidosis, also known as dermanyssosis, is a frequently unrecognized form of dermatitis, following human infestation with avian mites of the genera Dermanyssus or Ornithonyssus. It is characterized by pruritic erythematous papules, macules and urticaria, with itching and irritation resulting from the saliva the mites secrete while feeding. These bites are commonly found around the neck and areas covered by clothing, but can be found elsewhere on the body. The avian mite Dermanyssus gallinae can also infest various body parts, including the ear canal and scalp.
Ornithonyssus is a mite genus of the family Macronyssidae.
Ophionyssus natricis, the reptile mite, is a parasitic mite most commonly found on snakes, but also occurring on captive lizards, turtles, crocodiles, and other reptiles. The parasites feed on snakes, which cause the bodies of the mites to be engorged with blood and fluids from the snake. Once the mites feed by puncturing through the snake skin, the snake usually shows symptoms of irritation and discomfort. The involvement of snake mites in transmission of infectious illnesses like inclusion body disease and ophidian paramyxovirus remains controversial. Human infestation has been reported.
Nosopsyllus fasciatus, the northern rat flea, is a species of flea found on domestic rats and house mice. Northern rat fleas are external parasites, living by hematophagy off the blood of rodents. N. fasciatus can bite humans, but they are more common parasites of rodents. Since they are associated with humans, they are common disease vectors that can spread from animals to humans. Diseases that can be spread through fleas include the plague and typhus. The rat flea is widespread due to their relationship to rodents and other vertebrates. They can be found co-infecting their host with other parasites.
Ornithonyssus bursa is a species of mite. It is most often a parasite of birds, but also has been found to bite humans and two species of mammals. It usually lives in birds' feathers, but for laying its eggs, it more often uses their nests rather than their feathers. Tropical fowl mites undergo five stages during their development: egg, larva, protonymph, deutonymph, and adult. During the last two stages, they suck blood from their host for food. They are often diurnal, whereas northern fowl mites are nocturnal in nature.
Mites that infest and parasitize domestic animals cause disease and loss of production. Mites are small invertebrates, most of which are free living but some are parasitic. Mites are similar to ticks and both comprise the order Acari in the phylum Arthropoda. Mites are highly varied and their classification is complex; a simple grouping is used in this introductory article. Vernacular terms to describe diseases caused by mites include scab, mange, and scabies. Mites and ticks have substantially different biology from, and are classed separately from, insects. Mites of domestic animals cause important types of skin disease, and some mites infest other organs. Diagnosis of mite infestations can be difficult because of the small size of most mites, but understanding how mites are adapted to feed within the structure of the skin is useful.
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Rodent mite dermatitis is an often unrecognized ectoparasitosis occurring after human contact with haematophagous mesostigmatid mites that infest rodents, such as house mice, rats and hamsters. The condition is associated with the tropical rat mite, spiny rat mite and house mouse mite which opportunistically feed on humans. Rodent mites are capable of surviving for long periods without feeding and travelling long distances when seeking hosts. Cases have been reported in homes, libraries, hospitals and care homes. A similar condition, known as gamasoidosis, is caused by avian mites.