 | This article needs additional citations for verification .(March 2014) |
Xenodiagnosis is a diagnostic method used to document the presence of infectious disease microorganisms or pathogens by exposing possibly infected tissue to a vector and then examining the vector for the presence of the microorganisms or pathogens it may have ingested. [1]
Xenodiagnosis has not been commonly used in diagnosing Lyme disease because in vitro cell culturing now serves the purpose, [2] however the process is commonly used to diagnose infections involving microorganisms such as trypanosomiasis.
Émile Brumpt introduced the xenodiagnosis technique into parasitological research and extensively studied such diseases as bilharzia, Chagas disease, onchocerciasis and leishmaniasis.
Medical professionals primarily use xenodiagnosis in determining the presence of a chronic infection of Trypanosoma cruzi (the flagellate that causes Chagas disease). Directly and definitively demonstrating the presence of this causative agent in a patient proves difficult. Therefore, the doctor allows a triatominae, a vector of the flagellate, to take a blood meal from the patient. The doctor later inspects the gut of the triatominae for growth of Trypanosoma cruzi.
Medical professionals historically successfully identified babesiosis with xenodiagnosis, both in hamsters for Babesia microti and in gerbils for Babesia divergens. They now use faster diagnostic measures.
Xenodiagnosis for filariasis is now obsolete.[ citation needed ]
Chagas disease, also known as American trypanosomiasis, is a tropical parasitic disease caused by Trypanosoma cruzi. It is spread mostly by insects in the subfamily Triatominae, known as "kissing bugs". The symptoms change over the course of the infection. In the early stage, symptoms are typically either not present or mild, and may include fever, swollen lymph nodes, headaches, or swelling at the site of the bite. After four to eight weeks, untreated individuals enter the chronic phase of disease, which in most cases does not result in further symptoms. Up to 45% of people with chronic infections develop heart disease 10–30 years after the initial illness, which can lead to heart failure. Digestive complications, including an enlarged esophagus or an enlarged colon, may also occur in up to 21% of people, and up to 10% of people may experience nerve damage.
Triatoma protracta is a species of bugs in the family Reduviidae. It is known commonly as the western bloodsucking conenose. It is distributed in the western United States and Mexico.
An infection is the invasion of tissues by pathogens, their multiplication, and the reaction of host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmissible disease or communicable disease, is an illness resulting from an infection.
Trypanosoma is a genus of kinetoplastids, a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Sarcomastigophora. The name is derived from the Greek trypano- (borer) and soma (body) because of their corkscrew-like motion. Most trypanosomes are heteroxenous and most are transmitted via a vector. The majority of species are transmitted by blood-feeding invertebrates, but there are different mechanisms among the varying species. Some, such as Trypanosoma equiperdum, are spread by direct contact. In an invertebrate host they are generally found in the intestine, but normally occupy the bloodstream or an intracellular environment in the vertebrate host.
Carlos Justiniano Ribeiro Chagas, or Carlos Chagas, was a Brazilian sanitary physician, scientist, and bacteriologist who worked as a clinician and researcher. He discovered Chagas disease, also called American trypanosomiasis, in 1909, while he was working at the Oswaldo Cruz Institute in Rio de Janeiro.
The members of the Triatominae, a subfamily of the Reduviidae, are also known as conenose bugs, kissing bugs, or vampire bugs. Other local names for them used in the Americas include barbeiros, vinchucas, pitos, chipos and chinches. Most of the 130 or more species of this subfamily feed on vertebrate blood; a very few species feed on invertebrates. They are mainly found and widespread in the Americas, with a few species present in Asia and Africa. These bugs usually share shelter with nesting vertebrates, from which they suck blood. In areas where Chagas disease occurs, all triatomine species are potential vectors of the Chagas disease parasite Trypanosoma cruzi, but only those species that are well adapted to living with humans are considered important vectors. Also, proteins released from their bites have been known to induce anaphylaxis in sensitive and sensitized individuals.
Triatoma infestans, commonly called winchuka or vinchuca in Argentina, Bolivia, Uruguay and Chile, barbeiro in Brazil, chipo in Venezuela and also known as "kissing bug" or "barber bug" in English, is a blood-sucking bug and the most important vector of Trypanosoma cruzi which can lead to Chagas disease. It is widespread in the Southern Cone countries of South America. This region has joined the control intervention called Southern Cone Initiative managed by the PAHO.
Dipetalogaster, a genus of Triatominae, the kissing bugs, has only a single species, Dipetalogaster maxima, which is found in the Mexican state of Baja California Sur. Originally the blood-sucking Dipetalogaster lived in crevices in rocks where it typically fed on lizards, but following human growth in its range it now also commonly feeds on humans and domestic animals.
Parabelminus is a genus of bugs in the subfamily Triatominae. The species of this genus could be found in Brazil, specially in Rio de Janeiro and Bahia. It is a vector of Chagas disease.
Megacolon is an abnormal dilation of the colon. This leads to hypertrophy of the colon. The dilation is often accompanied by a paralysis of the peristaltic movements of the bowel. In more extreme cases, the feces consolidate into hard masses inside the colon, called fecalomas, which can require surgery to be removed.
Panstrogylus geniculatus is a blood-sucking sylvatic insect noted as a putative vector of minor importance in the transmission of Trypanosoma cruzi to humans; this is a parasite, which causes Chagas disease. The insect is described as sylvatic; subsisting primarily in humid forests, and is also known to inhabit vertebrate nesting places such as those of the armadillo, and is also involved in enzootic transmission of T. cruzi to those species. It has wide distribution throughout 16 Latin American countries.
Trypanosoma cruzi is a species of parasitic euglenoids. Among the protozoa, the trypanosomes characteristically bore tissue in another organism and feed on blood (primarily) and also lymph. This behaviour causes disease or the likelihood of disease that varies with the organism: Chagas disease in humans, dourine and surra in horses, and a brucellosis-like disease in cattle. Parasites need a host body and the haematophagous insect triatomine is the major vector in accord with a mechanism of infection. The triatomine likes the nests of vertebrate animals for shelter, where it bites and sucks blood for food. Individual triatomines infected with protozoa from other contact with animals transmit trypanosomes when the triatomine deposits its faeces on the host's skin surface and then bites. Penetration of the infected faeces is further facilitated by the scratching of the bite area by the human or animal host.
A canine vector-borne disease (CVBD) is one of "a group of globally distributed and rapidly spreading illnesses that are caused by a range of pathogens transmitted by arthropods including ticks, fleas, mosquitoes and phlebotomine sandflies." CVBDs are important in the fields of veterinary medicine, animal welfare, and public health. Some CVBDs are of zoonotic concern.
Triatoma brasiliensis is now considered the most important Chagas disease vector in the semiarid areas of northeastern Brazil. T. brasiliensis occurs in 12 Brazilian states, including Maranhão, Piauí, Ceará, Rio Grande do Norte, and Paraíba.
Protozoan infections are parasitic diseases caused by organisms formerly classified in the kingdom Protozoa. They are usually contracted by either an insect vector or by contact with an infected substance or surface and include organisms that are now classified in the supergroups Excavata, Amoebozoa, SAR, and Archaeplastida.
Trypanosoma rangeli is a species of hemoflagellate excavate parasites of the genus Trypanosoma. Although infecting a variety of mammalian species in a wide geographical area in Central and South America, this parasite is considered non-pathogenic to these hosts. T. rangeli is transmitted by bite of infected triatomine bugs of the Reduviidae family, commonly known as barbeiro, winchuka(vinchuca), chinche, pito ou chupão.
Triatoma sanguisuga, also known as the Eastern Bloodsucking Conenose, is an insect of the Triatominae subfamily, known as kissing bugs. It is found throughout North America and Latin America, and is common in the Southeastern United States. They are generally 16 to 21 mm long, black or dark brown, with six reddish-orange spots along each side of a wide abdomen. They are winged, have kinked, six-segmented antennae, and have a slender, tapered proboscis used for feeding.
Triatoma gerstaeckeri is an assassin bug in the genus Triatoma. It is an important vector of Trypanosoma cruzi, the causative agent of Chagas disease. The range of T. gerstaeckeri is from the south-western United States to north-eastern Mexico. T. gerstaeckeri goes through three stages during its paurometabolous life cycle: egg, nymphal instars and adult.
Phytomonas is a genus of trypanosomatids that infect plant species. Initially described using existing genera in the family Trypanosomatidae, such as Trypanosoma or Leishmania, the nomenclature of Phytomonas was proposed in 1909 in light of their distinct hosts and morphology. When the term was originally coined, no strict criterion was followed, and the term was adopted by the scientific community to describe flagellate protozoa in plants as a matter of convenience. Members of the taxon are globally distributed and have been discovered in members of over 24 plant families. Of these 24, the two main families that are infected by Phytomonas are Euphorbiaceae and Asclepiadiacae. These protists have been found in hosts between 50° latitude North and South, and thus they can be found on all continents save for Antarctica.
Panstrongylus megistus is a blood-drinking insect in the subfamily Triatominae. It is found in the Guianas, Brazil, Bolivia, Paraguay, Uruguay and Argentina, and is an important vector of Trypanosoma cruzi, particularly in Brazil. Besides humans, P. megistus is known to feed on birds, rodents, horses, dogs, opossums and bats.