scholarly journals Entomological aspects of Chagas' disease transmission in the domestic habitat, Argentina

2004 ◽  
Vol 38 (2) ◽  
pp. 216-222 ◽  
Author(s):  
SS Catalá ◽  
LB Crocco ◽  
A Muñoz ◽  
G Morales ◽  
I Paulone ◽  
...  

OBJECTIVE: To study the risk of Trypanosoma cruzi domestic transmission using an entomological index and to explore its relationship with household's characteristics and cultural aspects. METHODS: There were studied 158 households in an endemic area in Argentina. Each household was classified according to an entomological risk indicator (number of risky bites/human). A questionnaire was administered to evaluate risk factors among householders. RESULTS: Infested households showed a wide range of risk values (0 to 5 risky bites/human) with skewed distribution, a high frequency of lower values and few very high risk households. Of all collected Triatoma infestans, 44% had had human blood meals whereas 27% had had dogs or chickens blood meals. Having dogs and birds sharing room with humans increased the risk values. Tidy clean households had contributed significantly to lower risk values as a result of low vector density. The infested households showed a 24.3% correlation between time after insecticide application and the number of vectors. But there was no correlation between the time after insecticide application and T. infestans' infectivity. The statistical analysis showed a high correlation between current values of the entomological risk indicator and Trypanosoma cruzi seroprevalence in children. CONCLUSIONS: The risk of T. cruzi domestic transmission assessed using an entomological index show a correlation with children seroprevalence for Chagas' disease and householders' habits.

2009 ◽  
Vol 42 (2) ◽  
pp. 107-109 ◽  
Author(s):  
Pablo Gustavo Scapellato ◽  
Edgardo Gabriel Bottaro ◽  
María Teresa Rodríguez-Brieschke

A study was conducted on all newborns from mothers with Chagas disease who were attended at Hospital Donación F. Santojanni between January 1, 2001, and August 31, 2007. Each child was investigated for the presence of Trypanosoma cruzi parasitemia through direct examination of blood under the microscope using the buffy coat method on three occasions during the first six months of life. Serological tests were then performed. Ninety-four children born to mothers infected with Trypanosoma cruzi were attended over the study period. Three of these children were born to mothers coinfected with the human immunodeficiency virus. Vertical transmission of Chagas disease was diagnosed in 13 children, in all cases by identifying parasitemia. The overall Chagas disease transmission rate was 13.8% (13/94). It was 100% (3/3) among the children born to mothers with HIV infection and 10.9% (10/91) among children born to mothers without HIV [Difference = 0.89; CI95 = 0.82-0.95; p = 0.0021]. We concluded that coinfection with HIV could increase the risk of vertical transmission of Chagas disease.


2021 ◽  
Vol 15 (5) ◽  
pp. e0009389
Author(s):  
Marta Victoria Cardinal ◽  
Gustavo Fabián Enriquez ◽  
Natalia Paula Macchiaverna ◽  
Hernán Darío Argibay ◽  
María del Pilar Fernández ◽  
...  

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.


Check List ◽  
2020 ◽  
Vol 16 (4) ◽  
pp. 989-989
Author(s):  
Solange Peixoto ◽  
Dayse da Silva Rocha ◽  
Carolina Dale ◽  
Cleber Galvão

Panstrongylus geniculatus (Latreille, 1811) is the most widely distributed species in Brazil. This study presents the first report of this species collected inside a building in the “Centro de Estudos Ambientais e Desenvolvimento Sustentável”, at the Vila Dois Rios, Ilha Grande, Rio de Janeiro, Brazil. The new record is important to understand the risk of Chagas disease transmission, mainly because this species is commonly found infected with Trypanosoma cruzi (Chagas, 1909).


2013 ◽  
Vol 19 ◽  
pp. 141-144 ◽  
Author(s):  
Nelly Lilian Rosio Buitrago ◽  
Marie France Bosseno ◽  
Etienne Waleckx ◽  
Philippe Brémond ◽  
Pablo Vidaurre ◽  
...  

2017 ◽  
Vol 11 (4) ◽  
pp. e0005507 ◽  
Author(s):  
Danielle Silva-dos-Santos ◽  
Juliana Barreto-de-Albuquerque ◽  
Bárbara Guerra ◽  
Otacilio C. Moreira ◽  
Luiz Ricardo Berbert ◽  
...  

2020 ◽  
Author(s):  
Gilmar Ribeiro ◽  
Cristiane Medeiros Moraes de Carvalho ◽  
Renato Freitas de Araújo ◽  
Fernanda Cardoso Lanza ◽  
Diego Lopes Paim Miranda ◽  
...  

Abstract Background: This study presents a descriptive analysis of the occurrence of synanthropic triatomine species in the state of Bahia, before and after the implementation of the vector control program. Methods: Occurrence and number of collected specimens in the municipalities were analyzed in two periods: (A) 1957 to 1971, before systematic vector control actions; and (B) 2006 to 2019, after the certification of interruption of Chagas disease transmission by Triatoma infestans. Results: In total, 17 species were recorded during period A and 21 during period B. Panstrongylus megistus was the most frequent species in period A (42%), while Triatoma pseudomaculata (42%) and T. sordida (38%) were more frequent in period B. In period A, T. infestans was found in 26 (9%) municipalities, and in period B it was found in 7 (2%). During period B, most triatomines (88%) were captured at the peridomestic habitats, with a predominance of T. sordida (85%). Species with greatest relative abundance within the household were T. sordida (49%), T. brasiliensis (27%), and T. pseudomaculata (15%). Conclusions: We have observed a clear reduction in the occurrence of P. megistus and T. infestans and an increase in the relative abundance and geographical distribution of T. sordida and T. pseudomaculata after 40 years of the vector-control program. High frequency of other triatomine species in the municipalities of the state of Bahia and a great abundance of T. sordida in recent years, highlight the need to reinforce permanent entomological surveillance actions for Chagas disease.


2018 ◽  
Author(s):  
Stéphanie Depickère ◽  
Gonzalo Marcelo Ramírez-Ávila ◽  
Jean-Louis Deneubourg

AbstractInsects of Triatominae subfamily are vectors of the parasite Trypanosoma cruzi, the etiological agent of Chagas disease affecting millions of people in Latin America. Some of these vector species, like Triatoma infestans, live in the human neighborhood, aggregating in walls or roof cracks during the day and going out to feed on animal or human blood at night. Except for their feeding specialization, these insects share this cycle of activities with many gregarious arthropod species. The understanding of how sex and T. cruzi infection affect their aggregation and geotaxis behavior is essential for understanding the spatial organization of the insects and the parasite dispersion. Experiments with non-infected and infected adults of T. infestans show that the insects presented a high negative geotaxis and aggregative behavior. Males had a higher negative geotaxis and a higher aggregation level than females. The aggregation level and the negative geotaxis were stronger in infected insects than in non-infected ones, the difference between sexes being maintained. The importance of these results is discussed in term of parasitic manipulation, dispersion of the vector and strategy of its monitoring.


2020 ◽  
Vol 119 (10) ◽  
pp. 3517-3522
Author(s):  
Ana Beatriz Bortolozo de Oliveira ◽  
Bianca Barbério Bogdan Tedeschi ◽  
Jader de Oliveira ◽  
Fernanda Fernandez Madeira ◽  
Luiz Roberto Falleiros Junior ◽  
...  

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Stéphanie Depickère ◽  
Gonzalo Marcelo Ramírez-Ávila ◽  
Jean-Louis Deneubourg

AbstractTriatominae insects are vectors of the parasite Trypanosoma cruzi, the etiological agent of Chagas disease affecting millions of people in Latin America. Some species, such as Triatoma infestans, live in the human neighborhood, aggregating in walls or roof cracks during the day and going out to feed blood at night. The comprehension of how sex and T. cruzi infection affect their aggregation and geotaxis is essential for understanding their spatial organization and the parasite dispersion. Experiments in laboratory-controlled conditions were carried out with groups of ten adults of T. infestans able to explore and aggregate on a vertical surface. The influence of the sex (male vs. female) and the proportion of infected insects in the group were tested (100% of infected insects vs. a small proportion of infected insects, named infected and potentially weakly infected groups, respectively). Therefore, four distinct groups of insects were tested: infected males, infected females, potentially weakly infected males, and potentially weakly infected females, with 12, 9, 15, and 16 replicates, respectively. The insects presented a high negative geotaxis and a strong aggregation behavior whatever the sex or their infection. After an exploration phase, these behaviors were stable in time. The insects exhibited a preferential vertical position, head toward the top of the setup. Males had a higher negative geotaxis and a higher aggregation level than females. Both behaviors were enhanced in groups of 100% infected insects, the difference between sexes being maintained. According to a comparison between experimental and theoretical results, geotaxis favors the aggregation that mainly results from the inter-attraction between individuals.


Sign in / Sign up

Export Citation Format

Share Document