Control of pyrethroid‐resistant populations of Triatoma infestans , the main vector of Trypanosoma cruzi , by treating dogs with fluralaner in the Argentine Chaco

2021 ◽  
Author(s):  
Mariano Alberto Laiño ◽  
Marta Victoria Cardinal ◽  
María Sol Gaspe ◽  
Gustavo Fabián Enriquez ◽  
Alejandra Alvedro ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Triatoma Infestans

scholarly journals Cardiac morbidity due to Chagas' disease in a rural community in Bolivia

1988 ◽  
Vol 101 (3) ◽  
pp. 655-660 ◽  
Author(s):  
Th. Weinke ◽  
K. Ueberrieiter ◽  
M. Alexander
Keyword(s):  
Health Education ◽  
Trypanosoma Cruzi ◽  
Rural Community ◽  
Preventive Measures ◽  
Triatoma Infestans ◽  
Bundle Branch Block ◽  
Cardiac Morbidity ◽  
House Improvement ◽  
Ecg Alterations ◽  
Anterior Hemiblock

SUMMARYThe prevalence of cardiac morbidity due to Change' disease was assessed in a rural community in Central Bolivia. Sixty-nine of 104 persons (66%) were seropositive to Trypanosoma cruzi by two serological methods. Two of 35 (6%) seronegative individuals presented with modest ECG alterations (left anterior hemiblock), but 21 of 69 (30%) seropositives showed modest and severe abnormalities (6 complete right bundle branch block. 2 polyfocal or frequent extrasystoles, 9 ischaemic ST alterations). A high percentage (56%) of domiciliary Triatoma infestans was infected with T. cruzi. There was a significant association between seropositivity and substandard housing. Priority preventive measures should thus include house improvement (to reduce bug infestation) and health education.

scholarly journals Incapacidade de evolução do Trypanosoma cruzi na hemocele de triatomíneos

1982 ◽  
Vol 77 (4) ◽  
pp. 431-436 ◽  
Author(s):  
Nelson J. Alvarenga ◽  
Elizabeth Bronfen
Keyword(s):  
Trypanosoma Cruzi ◽  
Triatoma Infestans

O exame da hemolinfa de triatomíneos (Triatoma infestans e Dipetalogastermaxima) infectados pelo Trypanosoma cruzi há 10, 15, 20 e 30 dias não revelaram a presença do flagelado. Material colhido e lavado da hemocele de D. maxima infectados, também foi negativo. A inoculação de formas sanguíneas do parasita e daquelas obtidas do conteúdo intestinal de triatomíneos na hemocele revelou que os parasitas não foram capazes de manter na hemolinfa uma infecção por mais de 40 dias e que não puderam penetrar no intestino dos triatomíneos. A inoculação de hemolinfa de insetos naturalmente infectados em camundongos recém-nascidos não induziu infecção.

scholarly journals Infestacion domestica por triatoma infestans y prevalencia de seropositivos al Trypanosoma cruzi en un area rural del nordeste argentino

1996 ◽  
Vol 29 (6) ◽  
pp. 549-555 ◽  
Author(s):  
M. Esther Bar ◽  
E.B. Oscherov ◽  
M.P. Damborsky ◽  
B.M. Alvarez ◽  
G. Mizdraji ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Triatoma Infestans ◽  
El Alto

Se llevó a cabo un estúdio epidemiológicopara obtener unpanorama general de la transmisión doméstica del Trypanosoma cruzi en áreas rurales del Departamento San Miguel, Conientes, Argentina. Se investigaron 100 viviendas precarias, 50,0% de las mismas resultó infestado por Triatoma infestans y 1,0% por T. sórdida, citãndose por primera vez para la provinda de Comentes la colonización domiciliaria de esta especie. El 23,1% de T. infestans estaba infectado por T. cruzi. La seroprevalencia de 388 pacientes analizados por hemaglutinacíôn indirecta e inmunofluorescencia indirecta fue 23,4%, destacándose el alto índice (12,9%) constatado en menores de 10 anos. Losporcentajes de seropositividad aumentaron con la edad, alcanzándose 50,0% de infectados entre los 31-40 anos. La infestación doméstica por T. infestans, la prevalencia humana de seropositivos al T. cruzi y las condiciones deprecariedad en que se desenvuelve la vida de los pobladores revelan la vigência de la endemia chagãsica en el área estudiada.

scholarly journals Enfermedad de Chagas crónica.Ausencia de Triatoma infestans intradomiciliario y persistencia de Trypanosoma cruzi circulante post-terapia

2004 ◽  
Vol 59 (3-4) ◽  
Author(s):  
INÉS ZULANTAY ◽  
FRANCISCA BOZÁN ◽  
CARLOS SALAS ◽  
NICOLÁS ZILLERUELO ◽  
ANTONIO OSUNA ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Triatoma Infestans

scholarly journals Trypanosoma cruzi VECTOR INFECTION RATE IS UNDERESTIMATED IN SOME LOCALITIES IN THE STATE OF BAHIA

2016 ◽  
Vol 45 (1) ◽  
pp. 55 ◽  
Author(s):  
Juciliane Haidamak ◽  
Márcia Kiyoe Shimada ◽  
Débora do Rocio Klisiowicz ◽  
Larissa Reifur
Keyword(s):  
Trypanosoma Cruzi ◽  
Infection Rate ◽  
The State ◽  
Triatoma Infestans

A Bahia foi o último estado brasileiro a ser declarado livre da transmissão da doença deChagas pelo Triatoma infestans em 2006. O programa designado para controle vetorial da transmissão da doença de Chagas está atualmente ativo, e os potenciais triatomíneos coletados por funcionários do Departamento da Saúde do Estado da Bahia são praticamente todos diagnosticados como negativos para Trypanosoma cruzi quando analisados pelo método parasitológico convencional direto. O objetivo deste estudo foi investigar se os triatomíneos da Bahia, de fato, não estão infectados por T. cruzi, utilizando-se, para isso, uma metodologia de diagnóstico mais sensível, como a reação em cadeia da polimerase do DNA do cinetoplasto (kDNA-PCR). Com a ajuda dos funcionários da área da saúde, foram analisados 51 triatomíneos provenientes de áreas do peridomicílio da região centro-norte do estado da Bahia.Dos insetos analisados, a maioria (60,8%) era Triatoma brasiliensis, 29,4% eram Triatoma pseudomaculata e 9,8% eram ninfas que não foram identificadas. Apenas um inseto, analisado pelo método parasitológico convencional direto, mostrou-se potencialmente positivo para T. cruzi e 31,4% foram positivos para T. cruzi pela kDNA-PCR. Quase a metade dos insetos infectados (41,9%) era constituída por T. brasiliensis, uma espécie com alto potencial para a transmissão de T. cruzi. Estes resultados demonstram que o número de triatomíneos infectados com elevado potencial de transmissão de T. cruzi pode ser maior do que o esperado em quatro localidades do estado da Bahia.

scholarly journals Long-term impact of a ten-year intervention program on human and canine Trypanosoma cruzi infection in the Argentine Chaco

2021 ◽  
Vol 15 (5) ◽  
pp. e0009389
Author(s):  
Marta Victoria Cardinal ◽  
Gustavo Fabián Enriquez ◽  
Natalia Paula Macchiaverna ◽  
Hernán Darío Argibay ◽  
María del Pilar Fernández ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Disease Transmission ◽  
Intervention Program ◽  
Substantial Reduction ◽  
Triatoma Infestans ◽  
Incident Case ◽  
Cross Sectional ◽  
Vector Borne ◽  
Long Term Impact

Background Interruption of domestic vector-borne transmission of Trypanosoma cruzi is still an unmet goal in several American countries. In 2007 we launched a long-term intervention program aimed to suppress house infestation with the main domestic vector in southern South America (Triatoma infestans) and domestic transmission in Pampa del Indio, a resource-constrained, hyperendemic municipality with 1446 rural houses inhabited by Creole and indigenous people, in the Argentine Chaco ecoregion. Here, we assessed whether the 10-year insecticide-based program combined with community mobilization blocked vector-borne domestic transmission of T. cruzi to humans and dogs. Methods We carried out two municipality-wide, cross-sectional serosurveys of humans and dogs (considered sentinel animals) during 2016–2017 to compare with baseline data. We used a risk-stratified random sampling design to select 273 study houses; 410 people from 180 households and 492 dogs from 151 houses were examined for antibodies to T. cruzi using at least two serological methods. Results The seroprevalence of T. cruzi in children aged <16 years was 2.5% in 2017 (i.e., 4- to 11-fold lower than before interventions). The mean annual force of child infection (λ) sharply decreased from 2.18 to 0.34 per 100 person-years in 2017. One of 102 children born after interventions was seropositive for T. cruzi; he had lifetime residence in an apparently uninfested house, no outside travel history, and his mother was T. cruzi-seropositive. No incident case was detected among 114 seronegative people of all ages re-examined serologically. Dog seroprevalence was 3.05%. Among native dogs, λ in 2016 (1.21 per 100 dog-years) was 5 times lower than at program onset. Six native adult dogs born after interventions and with stable lifetime residence were T. cruzi-seropositive: three had exposure to T. infestans at their houses and one was an incident case. Conclusions These results support the interruption of vector-borne transmission of T. cruzi to humans in rural Pampa del Indio. Congenital transmission was the most likely source of the only seropositive child born after interventions. Residual transmission to dogs was likely related to transient infestations and other transmission routes. Sustained vector control supplemented with human chemotherapy can lead to a substantial reduction of Chagas disease transmission in the Argentine Chaco.

scholarly journals Investigation regarding the presence of Trypanosoma cruzi in triatomines and humans in rural households in the State of Paraná, southern Brazil

2021 ◽  
Vol 10 (10) ◽  
pp. e54101018366
Author(s):  
Ana Paula de Abreu ◽  
Hevillyn Fernanda Lucas da Silva ◽  
Marcella Paula Mansano Sarto ◽  
Giullia Ferreira Iunklaus ◽  
João Vitor Trovo ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Rural Households ◽  
Etiologic Agent ◽  
The State ◽  
Molecular Techniques ◽  
Triatoma Infestans ◽  
Southern Brazil ◽  
The North ◽  
Intestinal Contents ◽  
Cruzi Infection

Trypanosoma cruzi, the etiologic agent of Chagas disease (CD), is transmitted by hematophagous insects belonging to the subfamily Triatominae. After elimination of Triatoma infestans, the infestation of human dwellings by secondary species of vectors continues to pose a risk of transmission of the parasite. Our aim was to investigate the T. cruzi presence in triatomines and humans in rural households in the State of Paraná, southern Brazil. The capture of the insects was carried out by technicians of the municipalities after residents reported the outbreak. Five residents and 27 triatomines captured in four municipalities in the North and Midwest of the state were evaluated. The research of T. cruzi was carried out using parasitological, serological, and molecular techniques, in human blood, excreta, intestinal contents and insect macerate. Panstrongylus megistus, P. geniculatus and Triatoma sp.  were identified. Ten specimens of P. megistus were captured in a house in Mandaguari with five residents and presented an infection rate of 70% for T. cruzi like. All residents tested negative for T. cruzi infection. Another 15 P. megistus were captured in the peridomicile in Janiópolis and had 100.0% positivity. The only adult specimen of P. geniculatus captured in the intradomicile in Amaporã, as well as the nymph of Triatoma in the peridomicile in Paiçandu, were negative. The finding of P. megistus naturally infected by T. cruzi in households in rural area of Paraná demonstrates a potential risk of vector transmission of CD in these regions.

Gene deletion suggests a role for Trypanosoma cruzi surface glycoprotein GP72 in the insect and mammalian stages of the life cycle

1993 ◽  
Vol 106 (4) ◽  
pp. 1023-1033 ◽  
Author(s):  
A.R. de Jesus ◽  
R. Cooper ◽  
M. Espinosa ◽  
J.E. Gomes ◽  
E.S. Garcia ◽  
...  
Keyword(s):  
Life Cycle ◽  
Trypanosoma Cruzi ◽  
Gene Deletion ◽  
Surface Glycoprotein ◽  
Triatoma Infestans ◽  
Insect Vector ◽  
Null Mutant ◽  
Apparent Lack ◽  
Targeted Gene Deletion ◽  
Mouse Macrophages

We have explored the biological function of a surface glycoprotein (GP72) of Trypanosoma cruzi by studying a null mutant parasite, generated by targeted gene deletion. GP72 deletion affected parasite morphology in several stages of the life cycle. Insect midgut (epimastigote) forms had a detached flagellum (apomastigote) in the null mutant. The abnormal flagellar phenotype persisted during development of the infective (metacyclic) forms but there was no impairment in the acquisition of complement resistance, sialidase expression or cell infectivity. The GP72 null mutant could efficiently infect and proliferate in mouse macrophages and non-phagocytic L6E9 cells. The mammalian stages of the life cycle also showed major morphological abnormalities. During early subcultures in L6E9 cells, few extracellular fully flagellated forms, expressing markers characteristic of trypomastigotes, were seen. The extracellular population consisted almost exclusively of rounded forms with short flagella (micromastigote), which expressed an amastigote-specific surface marker and no sialidase. The propagation of the parasite was not affected, despite the apparent lack of the trypomastigote forms, which are thought to be primarily responsible for cell invasion. After some subcultures, the extracellular population changed to about equal numbers of micromastigotes and a range of flagellated forms that still did not include true trypomastigotes. Instead, the kinetoplast remained close to the nucleus and the flagellum emerged from the middle of the cell (mesomastigote). Half of the flagellum adhered to the cell body and the remainder was free at the anterior end. In Triatoma infestans, the survival of the mutant was dramatically reduced, suggesting that either GP72 itself, or the altered properties of the flagellum, were critical for establishment in the insect vector.

scholarly journals Elucidating the Mechanism of Trypanosoma cruzi Acquisition by Triatomine Insects: Evidence from a Large Field Survey of Triatoma infestans

2020 ◽  
Vol 5 (2) ◽  
pp. 87
Author(s):  
Aaron W. Tustin ◽  
Ricardo Castillo-Neyra ◽  
Laura D. Tamayo ◽  
Renzo Salazar ◽  
Katty Borini-Mayorí ◽  
...  
Keyword(s):  
Trypanosoma Cruzi ◽  
Regression Models ◽  
Control Strategies ◽  
Protozoan Parasite ◽  
Etiologic Agent ◽  
Triatoma Infestans ◽  
Large Field ◽  
Blood Sucking ◽  
Triatomine Bugs ◽  
Cruzi Infection

Blood-sucking triatomine bugs transmit the protozoan parasite Trypanosoma cruzi, the etiologic agent of Chagas disease. We measured the prevalence of T. cruzi infection in 58,519 Triatoma infestans captured in residences in and near Arequipa, Peru. Among bugs from infected colonies, T. cruzi prevalence increased with stage from 12% in second instars to 36% in adults. Regression models demonstrated that the probability of parasite acquisition was roughly the same for each developmental stage. Prevalence increased by 5.9% with each additional stage. We postulate that the probability of acquiring the parasite may be related to the number of feeding events. Transmission of the parasite does not appear to be correlated with the amount of blood ingested during feeding. Similarly, other hypothesized transmission routes such as coprophagy fail to explain the observed pattern of prevalence. Our results could have implications for the feasibility of late-acting control strategies that preferentially kill older insects.

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