Panstrongylus geniculatus
Encyclopedia
Panstrogylus geniculatus is a blood-sucking sylvatic
insect
noted as a putative vector of minor importance in the transmission of Trypanosoma cruzi
to humans; a parasite, which causes Chagas disease
. The species is described as sylvatic
; subsisting primarily in humid forests, and is also known to inhabit vertebrate nesting places such as that of the armadillo
(dasypus novemcinctus or dasypus
), and is also involved in enzootic
transmission of T. cruzi to those species. It has wide distribution throughout 16 Latin America
n countries.
There have been few scientific studies of this particular species because of the low number of collected specimens and difficulties in rearing and maintaining populations in the laboratory. However, currently P. geniculatus is receiving attention as a potential vector of Chagas disease
(American trypanosomiasis) due to reports of this species invading the domestic and peridomestic habitats over a vast area: Venezuela
, Colombia
, Brazil
, Peru
, Ecuador
, and Argentina
.
P. geniculatus is apparently in the process of domiciliation using the same strategies as highly domesticated species like Triatoma infestans
and Rhodnius prolixus
. This is also the case for other sylvatic triatomine species (Triatominae
) that are experiencing similar ecological pressures originated by human disruption of the natural habitat.
, used Panstrongylus specimens collected from Caracas City and the neighboring areas of Miranda and Vargas Sates. Through the use of a dot-ELISA
test and other techniques to determine the presence of trypanosome cruzi, it was found through the examination of feces that 67 of the 88 (76.1%) specimens collected were carrying the parasite and that 53 (60.2%) of those reacted positively to human antiserum.
Sylvatic
Sylvatic is a scientific term referring to diseases or pathogens affecting only wild animals. In the context of animal research, its opposite is domestic, which refers to pets, farm animals or other animals which do not dwell in the wild.*Examples: sylvatic rabies; sylvatic and domestic bacterial...
insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
noted as a putative vector of minor importance in the transmission of Trypanosoma cruzi
Trypanosoma cruzi
Trypanosoma cruzi is a species of parasitic euglenoid trypanosomes. This species causes the trypanosomiasis diseases in humans and animals in America...
to humans; a parasite, which causes Chagas disease
Chagas disease
Chagas disease is a tropical parasitic disease caused by the flagellate protozoan Trypanosoma cruzi. T. cruzi is commonly transmitted to humans and other mammals by an insect vector, the blood-sucking insects of the subfamily Triatominae most commonly species belonging to the Triatoma, Rhodnius,...
. The species is described as sylvatic
Sylvatic
Sylvatic is a scientific term referring to diseases or pathogens affecting only wild animals. In the context of animal research, its opposite is domestic, which refers to pets, farm animals or other animals which do not dwell in the wild.*Examples: sylvatic rabies; sylvatic and domestic bacterial...
; subsisting primarily in humid forests, and is also known to inhabit vertebrate nesting places such as that of the armadillo
Armadillo
Armadillos are New World placental mammals, known for having a leathery armor shell. Dasypodidae is the only surviving family in the order Cingulata, part of the superorder Xenarthra along with the anteaters and sloths. The word armadillo is Spanish for "little armored one"...
(dasypus novemcinctus or dasypus
Dasypus
Dasypus is a genus of armadillo in the Dasypodidae family. It is the only genus in the subfamily Dasypodinae and contains the following species:*Nine-banded Armadillo, Dasypus novemcinctus*Seven-banded Armadillo, Dasypus septemcinctus...
), and is also involved in enzootic
Enzootic
Enzootic is the non-human equivalent of endemic and means, in a broad sense, "belonging to" or "native to", "characteristic of", or "prevalent in" a particular geography, race, field, area, or environment; native to an area or scope....
transmission of T. cruzi to those species. It has wide distribution throughout 16 Latin America
Latin America
Latin America is a region of the Americas where Romance languages – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...
n countries.
There have been few scientific studies of this particular species because of the low number of collected specimens and difficulties in rearing and maintaining populations in the laboratory. However, currently P. geniculatus is receiving attention as a potential vector of Chagas disease
Chagas disease
Chagas disease is a tropical parasitic disease caused by the flagellate protozoan Trypanosoma cruzi. T. cruzi is commonly transmitted to humans and other mammals by an insect vector, the blood-sucking insects of the subfamily Triatominae most commonly species belonging to the Triatoma, Rhodnius,...
(American trypanosomiasis) due to reports of this species invading the domestic and peridomestic habitats over a vast area: Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
, Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, Peru
Peru
Peru , officially the Republic of Peru , is a country in western South America. It is bordered on the north by Ecuador and Colombia, on the east by Brazil, on the southeast by Bolivia, on the south by Chile, and on the west by the Pacific Ocean....
, Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
, and Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
.
P. geniculatus is apparently in the process of domiciliation using the same strategies as highly domesticated species like Triatoma infestans
Triatoma infestans
Triatoma infestans, commonly called vinchuca and also known as "barber bug", is a blood-sucking bug and the most important vector of Trypanosoma cruzi which can lead to Chagas disease...
and Rhodnius prolixus
Rhodnius prolixus
Rhodnius prolixus is the second most important triatomine vector of the Chagas parasite due to its efficient adaptation to the human domicile in northern South America, where sylvatic populations also exist, and in Central America where it is exclusively domestic...
. This is also the case for other sylvatic triatomine species (Triatominae
Triatominae
The members of Triatominae , a subfamily of Reduviidae, are also known as conenose bugs, kissing bugs, assassin bugs or triatomines. Most of the 130 or more species of this subfamily are haematophagous, i.e. feed on vertebrate blood; a very few species feed on other invertebrates...
) that are experiencing similar ecological pressures originated by human disruption of the natural habitat.
Prevalence in Venezuela
A 2005 study conducted by the Universidad Central de VenezuelaCentral University of Venezuela
The Central University of Venezuela is a premier public University of Venezuela located in Caracas...
, used Panstrongylus specimens collected from Caracas City and the neighboring areas of Miranda and Vargas Sates. Through the use of a dot-ELISA
ELISA
Enzyme-linked immunosorbent assay , is a popular format of a "wet-lab" type analytic biochemistry assay that uses one sub-type of heterogeneous, solid-phase enzyme immunoassay to detect the presence of a substance in a liquid sample."Wet lab" analytic biochemistry assays involves detection of an...
test and other techniques to determine the presence of trypanosome cruzi, it was found through the examination of feces that 67 of the 88 (76.1%) specimens collected were carrying the parasite and that 53 (60.2%) of those reacted positively to human antiserum.