Yersinia pestis is a gram-negative, non-motile, coccobacillus bacterium without spores that is related to both Yersinia pseudotuberculosis and Yersinia enterocolitica. It is a facultative anaerobic organism that can infect humans via the Oriental rat flea. It causes the disease plague, which caused the first plague pandemic and the Black Death, the deadliest pandemic in recorded history. Plague takes three main forms: pneumonic, septicemic, and bubonic. Yersinia pestis is a parasite of its host, the rat flea, which is also a parasite of rats, hence Y. pestis is a hyperparasite.
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.
Toxocariasis is an illness of humans caused by the dog roundworm and, less frequently, the cat roundworm. These are the most common intestinal roundworms of dogs, coyotes, wolves and foxes and domestic cats, respectively. Humans are among the many "accidental" or paratenic hosts of these roundworms.
Hymenolepiasis is infestation by one of two species of tapeworm: Hymenolepis nana or H. diminuta. Alternative names are dwarf tapeworm infection and rat tapeworm infection. The disease is a type of helminthiasis which is classified as a neglected tropical disease.
Tunga penetrans is a species of flea also known as the jigger, jigger flea, chigoe, chigo, chigoe flea, chigo flea, nigua, niknik, sand flea, or burrowing flea. It is a parasitic insect found in most tropical and sub-tropical climates. In its parasitic phase it has significant impact on its hosts, which include humans and certain other mammalian species. A parasitical infestation of T. penetrans is called tungiasis. Jiggers are often confused with chiggers, a type of mite. Jiggers are native to Central and South America, and have been introduced by colonialists to sub-Saharan Africa.
Tungiasis is an inflammatory skin disease caused by infection with the female ectoparasitic Tunga penetrans, a flea also known as the chigoe, chigo, chigoe flea, chigo flea, jigger, nigua, sand flea, or burrowing flea. The flea and the disease that it causes are found in the tropical parts of Africa, the Caribbean, Central and South America, and India. Tunga penetrans is the smallest known flea, measuring 1 mm across. It is also known in Latin America as the nigua and bicho de pie (Spanish) or bicho de pé (Portuguese), literally "foot bug". Tunga penetrans is a member of the genus Tunga, which comprises 13 species.
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.
The discipline of medical entomology, or public health entomology, and also veterinary entomology is focused upon insects and arthropods that impact human health. Veterinary entomology is included in this category, because many animal diseases can "jump species" and become a human health threat, for example, bovine encephalitis. Medical entomology also includes scientific research on the behavior, ecology, and epidemiology of arthropod disease vectors, and involves a tremendous outreach to the public, including local and state officials and other stake holders in the interest of public safety.
Angiostrongyliasis is an infection by a roundworm of the Angiostrongylus type. Symptoms may vary from none, to mild, to meningitis.
Bubonic plague is one of three types of plague caused by the bacterium Yersinia pestis. One to seven days after exposure to the bacteria, flu-like symptoms develop. These symptoms include fever, headaches, and vomiting, as well as swollen and painful lymph nodes occurring in the area closest to where the bacteria entered the skin. Acral necrosis, the dark discoloration of skin, is another symptom. Occasionally, swollen lymph nodes, known as "buboes", may break open.
Pollenia rudis, the common cluster fly, is a species of fly in the family Polleniidae. Pollenia rudis is also known as the attic fly, the loft fly, pollenie du lombric [French], and the buckwheat fly. During the autumn and winter months, Pollenia rudis can be found overwintering inside attics or lofts. This sluggish species can be found “clustering” near the interior windows of a warm structure.
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.
The dog flea is a species of flea that lives as an ectoparasite on a wide variety of mammals, particularly the domestic dog and cat. It closely resembles the cat flea, Ctenocephalides felis, which can live on a wider range of animals and is generally more prevalent worldwide.
A rat flea is a parasite of rats.
Ornithonyssus bacoti is a hematophagous parasite. It feeds on blood and serum from many hosts. 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. 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.
Trypanosoma lewisi is a globally distributed parasite of Rattus species and other rodents such as mice, and of kangaroo rats in America. Among these host species were two endemic species of rats: Rattus macleari and Rattus nativitatis. Both are now believed to be extinct. It is not very clear whether or not the same parasite infected both species. However, both parasites are very similar. The northern rat flea acts as the vector for the parasite, harboring the epimastigote stage in its midgut. The trypomastigote is the stage that is present in the main host, the rodent. The epimastigote form attaches itself to the rectum of the insect using its flagella to burrow through the rectal walls. The parasites also appear in the flea's feces. Ingestion of either the flea or its feces during grooming infects the host rodent with the parasites. T. lewisi is normally non-pathogenic but is known to have produced fatal infections in rats.
Urban plague is an infectious disease among rodent species that live in close association with humans in urban areas. It is caused by the bacterium Yersinia pestis which is the same bacterium that causes bubonic and pneumonic plague in humans. Plague was first introduced into the United States in 1900 by rat–infested steamships that had sailed from affected areas, mostly from Asia. Urban plague spread from urban rats to rural rodent species, especially among prairie dogs in the western United States.
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.
Cuterebra fontinella, the mouse bot fly, is a species of New World skin bot fly in the family Oestridae. C. fontinella is typically around 1 cm (0.39 in) in length with a black and yellow color pattern. C. fontinella develops by parasitizing nutrients from its host, typically the white-footed mouse. C. fontinella has even been known to parasitize humans in rare cases. Individuals parasitized by C. fontinella will develop a large bump on the skin that is indicative of parasitization.
