1
|
de Sousa Leite L, de Rezende Feres VC, Scalize PS. Predictor Variables in the Spread of Chagas Disease in Rural Areas. Pathogens 2024; 13:394. [PMID: 38787245 PMCID: PMC11124446 DOI: 10.3390/pathogens13050394] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 05/07/2024] [Accepted: 05/07/2024] [Indexed: 05/25/2024] Open
Abstract
Over a hundred years ago after the discovery of Chagas disease (CD) in Brazil, the World Health Organization estimates a number of 6 to 7 million people infected by Trypanosoma cruzi worldwide. Therefore, the goal of this work was to identify variables related to the spread of infection by T. cruzi in humans living in rural areas, seeking predictor variables. A systematic review of the literature has been conducted, with a search in the Scopus platform, using the search string "Chagas disease" and "rural", resulting in 85 valid and analyzed scientific studies (1977 and 2022). Twenty-seven predictor variables have been acquired, and 19 of them have been grouped, such as: socioeconomic and educational, housing, environmental, sanitary, and cultural; and 8 variables related to T. cruzi seropositive individuals. The predictor variables yielded significant results (p-value < 0.05) in 59.5% of the cases (195/328), with a median of 66.7%. In other words, studies relating to 50% of the 27 variables showed significance equal to or greater than 66.7% of the time. The independent variables with the highest proportion of significant data (p-value < 0.05) were Education (87.6%), Intradomicile building (70%), Domestic animals (69.6%), and Triatomines (69.2%) in the households. Some variables reached 100%; however, few articles were found, indicating the need for further research, especially for Sanitation and Culture. It has been concluded that, in the several contexts found, the social vulnerability and lack of information led the individual to living in environments where inhabitability is inadequate, to perform limited work activity and develop habits and behaviors which impair them in an environmental insalubrity situation, favorable to the access of vectors and pathogens of anthropozoonoses such as CD.
Collapse
Affiliation(s)
- Liziana de Sousa Leite
- Post-Graduation Program in Environmental Sciences (CIAMB), Federal University of Goiás, Goiania 74605-170, Brazil;
| | | | - Paulo Sérgio Scalize
- Post-Graduation Program in Environmental Sciences (CIAMB) and the Post-Graduation Program in Sanitary and Environmental Engineering (PPGEAS), Federal University of Goiás, Goiania 74605-170, Brazil
| |
Collapse
|
2
|
Macchiaverna NP, Enriquez GF, Gaspe MS, Rodríguez-Planes LI, Martinez PR, Gürtler RE, Cardinal MV. Human Trypanosoma cruzi infection in the Argentinean Chaco: risk factors and identification of households with infected children for treatment. Parasit Vectors 2024; 17:41. [PMID: 38287434 PMCID: PMC10826042 DOI: 10.1186/s13071-024-06125-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Accepted: 01/08/2024] [Indexed: 01/31/2024] Open
Abstract
BACKGROUND Chagas disease is a neglected tropical disease (NTD). Cost-effective strategies for large-scale implementation of diagnosis and etiological treatment are urgently needed to comply with NTD control goals. We determined the seroprevalence of Trypanosoma cruzi infection and associated risk factors in a well-defined rural population of Pampa del Indio municipality including creole and indigenous (Qom) households and developed two indices to identify houses harboring infected children. METHODS We serodiagnosed and administered a questionnaire to 1337 residents (48.2% of the listed population) in two sections of the municipality (named Areas II and IV) 6-9 years after deploying sustained vector control interventions. Multiple logistic regression models were used to evaluate the relationship between human infection and a priori selected predictors. Two risk indices were constructed based on environmental and serostatus variables, and we used spatial analysis to test whether households harboring T. cruzi-seropositive children were randomly distributed. RESULTS The global seroprevalence of T. cruzi infection was 24.8%. Human infection was positively and significantly associated with exposure time to triatomines, the household number of seropositive co-inhabitants, maternal seropositivity for T. cruzi, recent residence at the current house and the presence of suitable walls for triatomine colonization in the domicile. The pre-intervention mean annual force of infection (FOI) was 1.23 per 100 person-years. Creoles from Area IV exhibited the highest seroprevalence and FOI; Qom people from both areas displayed intermediate ones and creoles from Area II the lowest. Three hotspots of infected children were spatially associated with hotspots of triatomine abundance at baseline and persistent house infestation. No child born after vector control interventions was T. cruzi seropositive except for one putative transplacental case. Two simple risk indices (based on self-reported inhabiting an infested house and suitable walls for triatomines or maternal serostatus) identified 97.3-98.6% of the households with at least one T. cruzi-seropositive child. CONCLUSIONS We showed strong heterogeneity in the seroprevalence of T. cruzi infection within and between ethnic groups inhabiting neighboring rural areas. Developed indices can be used for household risk stratification and to improve access of rural residents to serodiagnosis and treatment and may be easily transferred to primary healthcare personnel.
Collapse
Affiliation(s)
- Natalia P Macchiaverna
- Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina.
| | - Gustavo F Enriquez
- Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - M Sol Gaspe
- Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Lucía I Rodríguez-Planes
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
- Universidad Nacional de Tierra del Fuego, Instituto de Ciencias Polares, Ambiente y Recursos Naturales, Onas 450, 9410, Ushuaia, Argentina
- Administración de Parques Nacionales, Dirección Regional Patagonia Austral, Ushuaia, Argentina
| | | | - Ricardo E Gürtler
- Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - M Victoria Cardinal
- Facultad de Ciencias Exactas y Naturales, Laboratorio de Eco-Epidemiología, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| |
Collapse
|
3
|
Gürtler RE, Enriquez GF, Gaspe MS, Macchiaverna NP, Del Pilar Fernández M, Rodríguez-Planes LI, Provecho YM, Cardinal MV. The Pampa del Indio project: sustainable vector control and long-term declines in the prevalence and abundance of Triatoma infestans infected with Trypanosoma cruzi in the Argentine Chaco. Parasit Vectors 2023; 16:258. [PMID: 37528423 PMCID: PMC10394798 DOI: 10.1186/s13071-023-05861-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Accepted: 06/30/2023] [Indexed: 08/03/2023] Open
Abstract
BACKGROUND The Gran Chaco region is a major hotspot of Chagas disease. We implemented a 9-year program aimed at suppressing house infestation with Triatoma infestans and stopping vector-borne transmission to creole and indigenous (Qom) residents across Pampa del Indio municipality (Argentine Chaco). The aim of the present study was to assess the intervention effects on parasite-based transmission indices and the spatial distribution of the parasite, and test whether house-level variations in triatomine infection with Trypanosoma cruzi declined postintervention and were influenced by household ethnicity, persistent infestation linked to pyrethroid resistance and other determinants of bug infection. METHODS This longitudinal study assessed house infestation and bug infection with T. cruzi before and after spraying houses with pyrethroids and implemented systematic surveillance-and-response measures across four operational areas over the period 2007-2016. Live triatomines were individually examined for infection by optical microscopy or kinetoplast DNA (kDNA)-PCR and declared to be infected with T. cruzi when assessed positive by either method. RESULTS The prevalence of infection with T. cruzi was 19.4% among 6397 T. infestans examined. Infection ranged widely among the study areas (12.5-26.0%), household ethnicity (15.3-26.9%), bug ecotopes (1.8-27.2%) and developmental stages (5.9-27.6%), and decreased from 24.1% (baseline) to 0.9% (endpoint). Using random-intercept multiple logistic regression, the relative odds of bug infection strongly decreased as the intervention period progressed, and increased with baseline domestic infestation and bug stage and in Qom households. The abundance of infected bugs and the proportion of houses with ≥ 1 infected bug remained depressed postintervention and were more informative of area-wide risk status than the prevalence of bug infection. Global spatial analysis revealed sharp changes in the aggregation of bug infection after the attack phase. Baseline domestic infestation and baseline bug infection strongly predicted the future occurrence of bug infection, as did persistent domestic infestation in the area with multiple pyrethroid-resistant foci. Only 19% of houses had a baseline domestic infestation and 56% had ever had ≥ 1 infected bug. CONCLUSIONS Persistent bug infection postintervention was closely associated with persistent foci generated by pyrethroid resistance. Postintervention parasite-based indices closely agreed with human serosurveys at the study endpoint, suggesting transmission blockage. The program identified households and population subgroups for targeted interventions and opened new opportunities for risk prioritization and sustainable vector control and disease prevention.
Collapse
Affiliation(s)
- Ricardo Esteban Gürtler
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
- Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Universidad de Buenos Aires, Buenos Aires, Argentina.
| | - Gustavo Fabián Enriquez
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - María Sol Gaspe
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Natalia Paula Macchiaverna
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina
- Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Universidad de Buenos Aires, Buenos Aires, Argentina
| | | | - Lucía Inés Rodríguez-Planes
- Instituto de Ciencias Polares, Ambiente y Recursos Naturales, Universidad Nacional de Tierra del Fuego, Ushuaia, Argentina
| | - Yael Mariana Provecho
- Ministerio de Salud de la Nación, Dirección de Control de Enfermedades Transmitidas por Vectores, Buenos Aires, Argentina
| | - Marta Victoria Cardinal
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
- Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)-Universidad de Buenos Aires, Buenos Aires, Argentina.
| |
Collapse
|
4
|
Weinberg D, Casale MF, Cejas RG, Hoyos R, Periago MV, Segura E, Abril MC. Chagas prevention and control in an endemic area from the Argentinian Gran Chaco Region: Data from 14 years of uninterrupted intervention. PLoS Negl Trop Dis 2023; 17:e0011410. [PMID: 37314995 DOI: 10.1371/journal.pntd.0011410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Accepted: 05/23/2023] [Indexed: 06/16/2023] Open
Abstract
BACKGROUND Chagas Disease (ChD) is a Neglected Tropical Disease (NTD) affecting 6 to 7 million people worldwide, mostly from Latin America. In Argentina, a national control program has been implemented since 1962, yet there are still an estimated 1.6 million infected individuals. Control programs were based almost exclusively on entomological surveillance and chemical control of households and were not continuous given a lack of coordination and resources. Argentina´s ChD program was originally vertical and centralized; later, it was partially and, in general, unsuccessfully transferred to the provinces. Herein, we describe the implementation of a control program for ChD with an ecohealth approach in rural settlements around the city of Añatuya, Santiago del Estero. METHODS The program included yearly household visits for entomological surveillance and control, health promotion workshops, and structural house improvements. Improved structures included internal and external walls and roofs, as well as the construction of water wells and latrines, and the organization and improvement of peri-domestic structures. Activities were carried out by specifically trained personnel except for house improvements, which were performed by the community, under technical guidance and provision of materials. Data was collected using standardized questionnaires for household characterization, entomological infestation status and chemical control activities. RESULTS This program was continuously implemented since 2005 with high community participation and adherence, incorporating 13 settlements and 502 households. During the surveillance phase, 4,193 domiciliary inspections were performed, and both the intra- and peri-domestic infestation rate were reduced from 17.9% to 0.2% (P < 0.01) and from 20.4% to 3%, respectively. Additionally, 399 households were structurally improved. CONCLUSION The program is still ongoing and, after 14 years of implementation, has built social networks and collaboration between implementers and beneficiaries with a reduction of T. infestans infestation in the intra- and peri-domicile. This reduction, especially inside the household, has enabled access to diagnosis and treatment of the population, with minimal risk of re-infection.
Collapse
Affiliation(s)
| | | | | | - Rafael Hoyos
- Fundación Mundo Sano, Añatuya, Santiago del Estero, Argentina
| | - María Victoria Periago
- Fundación Mundo Sano, Buenos Aires, Argentina
- Consejo Nacional de investigaciones Científica y Técnicas (CONICET), Buenos Aires, Argentina
| | - Elsa Segura
- Consejo Nacional de investigaciones Científica y Técnicas (CONICET), Buenos Aires, Argentina
| | | |
Collapse
|
5
|
Alejandra A, Sol GM, Fabián EG, Paula MN, Esteban GR, Victoria CM. Marginal risk of domestic vector-borne Trypanosoma cruzi transmission after improved vector control of Triatoma infestans across a rural-to-urban gradient in the Argentine Chaco. Acta Trop 2023; 243:106933. [PMID: 37119837 DOI: 10.1016/j.actatropica.2023.106933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 05/01/2023]
Abstract
The interruption of domestic vector-borne transmission of Trypanosoma cruzi in the Americas remains one of the main goals of the World Health Organization 2021-2030 road map for neglected tropical diseases. We implemented a longitudinal intervention program over 2015-2022 to suppress (peri)domestic Triatoma infestans in the municipality of Avia Terai, Chaco Province, Argentina and found that house infestation (3851 houses inspected) and triatomine abundance decreased over the first 2 years post-intervention (YPI), and remained stable thereafter associated to moderate pyrethroid resistant foci. Here we assessed selected components of transmission risk after interventions across the rural-to-urban gradient. We used multistage random sampling to select a municipality-wide sample of T. infestans. We examined 356 insects collected in 87 houses for T. cruzi infection using kDNA-PCR and identified their bloodmeal sources using an indirect ELISA. The overall prevalence of T. cruzi infection post-intervention was 1.7% (95% CI 0.7-3.6). Few houses (5.7%) (95% CI 2.5-12.8) harbored infected triatomines across the gradient. Infected triatomines were found in 5 peri-urban or rural dwellings over 1-4 years post-intervention. No infected insect was found in the urban area. The human blood index decreased from 66.2 at baseline to 42.8 at 1YPI and then increased to 92.9 at 4-5 YPI in the few infested domiciles detected. The percentage of houses with human-fed bugs displayed a similar temporal trend. Our results indicate marginal risks of domestic vector-borne transmission across the district after implementation of the intervention program. Ensuring sustainable vector surveillance coupled with human etiological diagnosis and treatment in hiperendemic areas like the Gran Chaco region, is urgently needed. 252 words.
Collapse
Affiliation(s)
- Alvedro Alejandra
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - Gaspe María Sol
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - Enriquez Gustavo Fabián
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - Macchiaverna Natalia Paula
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - Gürtler Ricardo Esteban
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - Cardinal Marta Victoria
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Laboratorio de Eco-Epidemiología. Intendente Güiraldes 2160, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina; CONICET-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.
| |
Collapse
|
6
|
Gürtler RE, Laiño MA, Alvedro A, Enriquez GF, Macchiaverna NP, Gaspe MS, Cardinal MV. Treatment of dogs with fluralaner reduced pyrethroid-resistant Triatoma infestans abundance, Trypanosoma cruzi infection and human-triatomine contact in the Argentine Chaco. Parasit Vectors 2022; 15:257. [PMID: 35831874 PMCID: PMC9277862 DOI: 10.1186/s13071-022-05343-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 05/23/2022] [Indexed: 11/16/2022] Open
Abstract
Background Triatomine elimination efforts and the interruption of domestic transmission of Trypanosoma cruzi are hampered by pyrethroid resistance. Fluralaner, a long-lasting ectoparasiticide administered to dogs, substantially reduced site infestation and abundance of pyrethroid-resistant Triatoma infestans Klug (Heteroptera: Reduviidae) in an ongoing 10-month trial in Castelli (Chaco Province, Argentina). We assessed the effects of fluralaner on vector infection with T. cruzi and blood meal sources stratified by ecotope and quantified its medium-term effects on site infestation and triatomine abundance. Methods We conducted a placebo-controlled, before-and-after efficacy trial of fluralaner in 28 infested sites over a 22-month period. All dogs received either an oral dose of fluralaner (treated group) or placebo (control group) at 0 month post-treatment [MPT]. Placebo-treated dogs were rescue-treated with fluralaner at 1 MPT, as were all eligible dogs at 7 MPT. Site-level infestation and abundance were periodically assessed by timed manual searches with a dislodging aerosol. Vector infection was mainly determined by kDNA-PCR and blood meal sources were determined by enzyme-linked immunosorbent assay. Results In fluralaner-treated households, site infestation dropped from 100% at 0 MPT to 18–19% over the period 6–22 MPT while mean abundance plummeted from 5.5 to 0.6 triatomines per unit effort. In control households, infestation dropped similarly post-treatment. The overall prevalence of T. cruzi infection steadily decreased from 13.8% at 0–1 MPT (baseline) to 6.4% and subsequently 2.3% thereafter, while in domiciles, kitchens and storerooms it dropped from 17.4% to 4.7% and subsequently 3.3% thereafter. Most infected triatomines occurred in domiciles and had fed on humans. Infected-bug abundance plummeted after fluralaner treatment and remained marginal or nil thereafter. The human blood index of triatomines collected in domiciles, kitchens and storerooms highly significantly fell from 42.9% at baseline to 5.3–9.1% over the period 6–10 MPT, increasing to 36.8% at 22 MPT. Dog blood meals occurred before fluralaner administration only. The cat blood index increased from 9.9% at baseline to 57.9–72.7% over the period 6–10 MPT and dropped to 5.3% at 22 MPT, whereas chicken blood meals rose from 39.6% to 63.2–88.6%. Conclusion Fluralaner severely impacted infestation- and transmission-related indices over nearly 2 years, causing evident effects at 1 MPT, and deserves larger efficacy trials. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s13071-022-05343-2.
Collapse
Affiliation(s)
- Ricardo Esteban Gürtler
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina. .,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina.
| | - Mariano Alberto Laiño
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Alejandra Alvedro
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Gustavo Fabián Enriquez
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Natalia Paula Macchiaverna
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - María Sol Gaspe
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina.,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina
| | - Marta Victoria Cardinal
- Laboratory of Eco-Epidemiology, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina. .,Instituto de Ecología, Genética y Evolución de Buenos Aires, Consejo Nacional de Investigaciones Científicas y Técnicas, Ciudad Universitaria, Buenos Aires, Argentina.
| |
Collapse
|
7
|
Rivadeneira-Barreiro PE, Montes de Oca-Jiménez R, Vázquez-Chagoyán JC, Martínez-Subiela S, Morán-Loor A, Ochoa-García L, Zambrano-Rodríguez PC, Garg NJ, Varela-Guerrero JA. Trypanosoma cruzi co-infections with other vector borne diseases are frequent in dogs from the pacific coast of Ecuador. Microb Pathog 2021; 155:104884. [PMID: 33864876 DOI: 10.1016/j.micpath.2021.104884] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/20/2021] [Accepted: 03/22/2021] [Indexed: 10/21/2022]
Abstract
Dogs are a reservoir for Chagas disease, caused by Trypanosoma cruzi (T. cruzi), and other companion vector-borne diseases, including ehrlichiosis (Ehrlichia canis and Ehrlichia ewingii), anaplasmosis (Anaplasma phagocytophilum and Anaplasma platys), dirofilariasis (Dirofilaria immitis) and Lyme disease (Borrelia burgdorferi). This study has two key objectives: 1) to determine seroreactivity against T. cruzi in dogs from the town of Colón, in Portoviejo city, in the central coast of Ecuador; and 2) to establish the coinfection frequency of other companion vector-borne diseases in dogs positive for T. cruzi. Antibodies against T. cruzi were detected using two enzyme-linked immunosorbent assays. Diagnostic consensus between ELISA tests was established using the Cohen's Kappa coefficient. Other haemoparasitic diseases were detected using the IDEXX SNAP® 4Dx® kit in dogs previously diagnosed as T. cruzi-seropositive. From 84 dogs sampled, 57.14% (48/84) tested positive for T. cruzi. Co-infection analysis of 25 dogs positive for T. cruzi revealed antibodies also against Ehrlichia spp. (48%), Anaplasma spp. (28%), and Dirofilaria immitis (12%). These results provide a novel perspective regarding the status of these pathogens which co-infect dogs in Colón. Since all these pathogens are zoonotic, our findings should warn regional health authorities to implement sanitary programs, to better prevent and control vectors associated to these pathogens. On the other hand, human and veterinarian doctors, should consider that patients with a cardiac infection condition could be suffering co-infections with two or more vector transmitted pathogens.
Collapse
Affiliation(s)
- Pilar Eliana Rivadeneira-Barreiro
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Km 15.5 Carretera Panamericana Toluca-Atlacomulco, Toluca, Estado de México, C.P. 50200, México; Departamento de Veterinaria, Facultad de Ciencias Veterinarias, Universidad Técnica de Manabí, Portoviejo, Manabí, Ecuador
| | - Roberto Montes de Oca-Jiménez
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Km 15.5 Carretera Panamericana Toluca-Atlacomulco, Toluca, Estado de México, C.P. 50200, México.
| | - Juan Carlos Vázquez-Chagoyán
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Km 15.5 Carretera Panamericana Toluca-Atlacomulco, Toluca, Estado de México, C.P. 50200, México.
| | - Silvia Martínez-Subiela
- Interdisciplinary Laboratory of Clinical Analysis of the University of Murcia (Interlab-UMU), Regional Campus of International Excellence 'Campus Mare Nostrum', University of Murcia, Campus de Espinardo s/n, 30100, Espinardo, Murcia, Spain
| | | | - Laucel Ochoa-García
- Laboratorio Estatal de Salud Pública del Instituto de Salud del Estado de México, Independencia Oriente #1310 Colonia: Reforma y FFCC, CP. 50070, Toluca, Estado de México, México
| | - Pablo C Zambrano-Rodríguez
- Departamento de Veterinaria, Facultad de Ciencias Veterinarias, Universidad Técnica de Manabí, Portoviejo, Manabí, Ecuador
| | - Nisha Jain Garg
- Department of Microbiology & Immunology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX, 77555-1070, United States
| | - Jorge Antonio Varela-Guerrero
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Km 15.5 Carretera Panamericana Toluca-Atlacomulco, Toluca, Estado de México, C.P. 50200, México
| |
Collapse
|
8
|
Fernández MDP, Gaspe MS, Sartor P, Gürtler RE. Human Trypanosoma cruzi infection is driven by eco-social interactions in rural communities of the Argentine Chaco. PLoS Negl Trop Dis 2019; 13:e0007430. [PMID: 31841558 PMCID: PMC6936860 DOI: 10.1371/journal.pntd.0007430] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 12/30/2019] [Accepted: 10/25/2019] [Indexed: 01/11/2023] Open
Abstract
The transmission of Trypanosoma cruzi to humans is determined by multiple ecological, socio-economic and cultural factors acting at different scales. Their effects on human infection with T. cruzi have often been examined separately or using a limited set of ecological and socio-demographic variables. Herein, we integrated the ecological and social dimensions of human infection risk with the spatial distribution patterns of human and vector (Triatoma infestans) infection in rural communities of the Argentine Chaco composed of indigenous people (90% Qom) and a creole minority. We conducted serosurveys in 470 households aiming at complete population enumeration over 2012–2015. The estimated seroprevalence of T. cruzi prior to the implementation of an insecticide spraying campaign (2008) was 29.0% (N = 1,373 in 301 households), and was twice as large in Qom than creoles. Using generalized linear mixed models, human seropositive cases significantly increased with infected triatomine abundance, having a seropositive household co-inhabitant and household social vulnerability (a multidimensional index of poverty), and significantly decreased with increasing host availability in sleeping quarters (an index summarizing the number of domestic hosts for T. infestans). Vulnerable household residents were exposed to a higher risk of infection even at low infected-vector abundances. The risk of being seropositive increased significantly with house infestation among children from stable households, whereas both variables were not significantly associated among children from households exhibiting high mobility within the communities, possibly owing to less consistent exposures. Human infection was clustered by household and at a larger spatial scale, with hotspots of human and vector infection matching areas of higher social vulnerability. These results were integrated in a risk map that shows high-priority areas for targeted interventions oriented to suppress house (re)infestations, detect and treat infected children, and thus reduce the burden of future disease. Chagas disease is one of the main neglected tropical diseases (NTDs) affecting vulnerable communities in Latin America where transmission by triatomine vectors still occurs. Access to diagnosis and treatment is one of the remaining challenges for sustainable control of Chagas disease in endemic areas. In this study, we integrated the ecological and social determinants of human infection with the spatial component to identify individuals, households and geographic sectors at higher risk of infection. We found that human infection was more prevalent in indigenous people compared to creoles and increased with the abundance of infected vectors and with household social vulnerability (a multidimensional index of poverty). We also found that the social factors modulated the effect of the abundance of infected vectors: vulnerable-household residents were exposed to a higher risk of infection even at low infected-vector abundance, and human mobility within the area determined a lower and more variable exposure to the vector over time. These results were integrated in a risk map that showed high-priority areas, which can be used in designing cost-effective serological screening strategies adapted to resource-constrained areas.
Collapse
Affiliation(s)
- Maria del Pilar Fernández
- Universidad de Buenos Aires. Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, Buenos Aires, Argentina
- Earth Institute, Columbia University, New York, New York, United States of America
- * E-mail:
| | - Maria Sol Gaspe
- Universidad de Buenos Aires. Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, Buenos Aires, Argentina
| | - Paula Sartor
- Universidad de Buenos Aires. Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Buenos Aires, Argentina
- Ministerio de Salud Pública del Chaco, Resistencia, Chaco, Argentina
- Facultad de Ciencias Exactas, Naturales y Agrimensura, Universidad Nacional del Nordeste, Corrientes, Corrientes, Argentina
| | - Ricardo E. Gürtler
- Universidad de Buenos Aires. Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Ciudad Universitaria, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, Buenos Aires, Argentina
| |
Collapse
|
9
|
Flores-Ferrer A, Waleckx E, Rascalou G, Dumonteil E, Gourbière S. Trypanosoma cruzi transmission dynamics in a synanthropic and domesticated host community. PLoS Negl Trop Dis 2019; 13:e0007902. [PMID: 31834879 PMCID: PMC6934322 DOI: 10.1371/journal.pntd.0007902] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 12/27/2019] [Accepted: 11/04/2019] [Indexed: 12/26/2022] Open
Abstract
Trypanosoma cruzi is the causative agent of Chagas disease, a Neglected Tropical Disease affecting 8 million people in the Americas. Triatomine hematophagous vectors feed on a high diversity of vertebrate species that can be reservoirs or dead-end hosts, such as avian species refractory to T. cruzi. To understand its transmission dynamics in synanthropic and domesticated species living within villages is essential to quantify disease risk and assess the potential of zooprophylaxis. We developed a SI model of T. cruzi transmission in a multi-host community where vector reproduction and parasite transmission depend on a triatomine blood-feeding rate accounting for vector host preferences and interference while feeding. The model was parameterized to describe T. cruzi transmission in villages of the Yucatan peninsula, Mexico, using the information about Triatoma dimidiata vectors and host populations accumulated over the past 15 years. Extensive analyses of the model showed that dogs are key reservoirs and contributors to human infection, as compared to synanthropic rodents and cats, while chickens or other domesticated avian hosts dilute T. cruzi transmission despite increasing vector abundance. In this context, reducing the number of dogs or increasing avian hosts abundance decreases incidence in humans by up to 56% and 39%, respectively, while combining such changes reduces incidence by 71%. Although such effects are only reached over >10-years periods, they represent important considerations to be included in the design of cost-effective Integrated Vector Management. The concomitant reduction in T. cruzi vector prevalence estimated by simulating these zooprophylactic interventions could indeed complement the removal of colonies from the peridomiciles or the use of insect screens that lower vector indoor abundance by ~60% and ~80%. These new findings reinforce the idea that education and community empowerment to reduce basic risk factors is a cornerstone to reach and sustain the key objective of interrupting Chagas disease intra-domiciliary transmission.
Collapse
Affiliation(s)
- Alheli Flores-Ferrer
- UMR5096 ‘Laboratoire Génome et Développement des Plantes’, Université de Perpignan Via Domitia, Perpignan, France
| | - Etienne Waleckx
- Institut de Recherche pour le Développement, UMR INTERTRYP IRD, CIRAD, Université de Montpellier, Montpellier, France
- Laboratorio de Parasitología, Centro de Investigaciones Regionales ‘Dr. Hideyo Noguchi’, Universidad Autónoma deYucatán, Mérida, Yucatán, México
| | - Guilhem Rascalou
- UMR5096 ‘Laboratoire Génome et Développement des Plantes’, Université de Perpignan Via Domitia, Perpignan, France
| | - Eric Dumonteil
- Department of Tropical Medicine, School of Public Health and Tropical Medicine, and Vector-Borne and Infectious Disease Research Center, Tulane University, New Orleans, Louisiana, United States of America
| | - Sébastien Gourbière
- UMR5096 ‘Laboratoire Génome et Développement des Plantes’, Université de Perpignan Via Domitia, Perpignan, France
- Centre for the Study of Evolution, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| |
Collapse
|
10
|
Insights from quantitative and mathematical modelling on the proposed WHO 2030 goals for Chagas disease. Gates Open Res 2019; 3:1539. [PMID: 31781687 PMCID: PMC6856696 DOI: 10.12688/gatesopenres.13069.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/12/2019] [Indexed: 12/22/2022] Open
Abstract
Chagas disease (CD) persists as one of the neglected tropical diseases (NTDs) with a particularly large impact in the Americas. The World Health Organization (WHO) recently proposed goals for CD elimination as a public health problem to be reached by 2030 by means of achieving intradomiciliary transmission interruption (IDTI), blood transfusion and transplant transmission interruption, diagnostic and treatment scaling-up and prevention and control of congenital transmission. The NTD Modelling Consortium has developed mathematical models to study
Trypanosoma cruzi transmission dynamics and the potential impact of control measures. Modelling insights have shown that IDTI is feasible in areas with sustained vector control programmes and no presence of native triatomine vector populations. However, IDTI in areas with native vectors it is not feasible in a sustainable manner. Combining vector control with trypanocidal treatment can reduce the timeframes necessary to reach operational thresholds for IDTI (<2% seroprevalence in children aged <5 years), but the most informative age groups for serological monitoring are yet to be identified. Measuring progress towards the 2030 goals will require availability of vector surveillance and seroprevalence data at a fine scale, and a more active surveillance system, as well as a better understanding of the risks of vector re-colonization and disease resurgence after vector control cessation. Also, achieving scaling-up in terms of access to treatment to the expected levels (75%) will require a substantial increase in screening asymptomatic populations, which is anticipated to become very costly as CD prevalence decreases. Further modelling work includes refining and extending mathematical models (including transmission dynamics and statistical frameworks) to predict transmission at a sub-national scale, and developing quantitative tools to inform IDTI certification, post-certification and re-certification protocols. Potential perverse incentives associated with operational thresholds are discussed. These modelling insights aim to inform discussions on the goals and treatment guidelines for CD.
Collapse
|
11
|
Cardinal MV, Sartor PA, Gaspe MS, Enriquez GF, Colaianni I, Gürtler RE. High levels of human infection with Trypanosoma cruzi associated with the domestic density of infected vectors and hosts in a rural area of northeastern Argentina. Parasit Vectors 2018; 11:492. [PMID: 30165892 PMCID: PMC6118006 DOI: 10.1186/s13071-018-3069-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 08/20/2018] [Indexed: 01/18/2023] Open
Abstract
Background Insecticide spraying campaigns designed to suppress the principal vectors of the Chagas disease usually lack an active surveillance system that copes with house reinvasion. Following an insecticide campaign with no subsequent surveillance over a 12-year period, we implemented a longitudinal intervention programme including periodic surveys for Triatoma infestans, full-coverage house spraying with insecticides, and selective control in a well-defined rural area of the Argentinean Chaco inhabited by Creoles and one indigenous group (Qom). Here, we conducted a cross-sectional study and report the age-specific seroprevalence of human T. cruzi infection by group, and examine the association between human infection, the onset of the intervention, the relative density of infected domestic bugs, and the household number of infected people, dogs, or cats. Results The seroprevalence of infection among 691 residents examined was 39.8% and increased steadily with age, reaching 53–70% in those older than 20 years. The mean annual force of infection was 2.5 per 100 person-years (95% CI: 1.8–3.3%). Infection in children younger than 16 years born before the intervention programme was two to four times higher in houses with infected T. infestans than in houses without them and was six times higher when there were both infected dogs or cats and bugs than when they were absent. The model-averaged estimate of the intervention effect suggests that the odds of seropositivity were about nine times smaller for those born after the onset of the intervention than for those born before it, regardless of ethnic background, age, gender, household wealth, and cohabitation with T. cruzi-infected vectors or human hosts. Human infection was also closely associated with the baseline abundance of infected domestic triatomines and the number of infected cohabitants. Two of 43 children born after interventions were T. cruzi-seropositive; since their mothers were seropositive and both resided in apparently uninfested houses they were attributed to vertical transmission. Alternatively, these cases could be due to non-local vector-borne transmission. Conclusions Our study reveals high levels of human infection with T. cruzi in the Argentinean Chaco, and the immediate impact of sustained vector surveillance and selective control actions on transmission. Electronic supplementary material The online version of this article (10.1186/s13071-018-3069-0) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Marta Victoria Cardinal
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina. .,Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.
| | - Paula Andrea Sartor
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.,Present address: Departamento de Control de Enfermedades Transmitidas por Vectores, Ministerio de Salud del Chaco, Resistencia, Chaco, Argentina, Universidad Nacional del Nordeste, Resistencia, Chaco, Argentina
| | - María Sol Gaspe
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - Gustavo Fabián Enriquez
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| | - Ivana Colaianni
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.,Present address: Hospital Santojanni, Ciudad de Buenos Aires, Argentina
| | - Ricardo Esteban Gürtler
- Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales, Laboratory of Eco-Epidemiology, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas-Universidad de Buenos Aires. Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA), Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina
| |
Collapse
|
12
|
García-Jordán N, Berrizbeitia M, Rodríguez J, Concepción JL, Cáceres A, Quiñones W. [Seroprevalence of Trypanosoma cruzi infection in the rural population of Sucre State, Venezuela]. CAD SAUDE PUBLICA 2017; 33:e00050216. [PMID: 29091170 DOI: 10.1590/0102-311x00050216] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Accepted: 01/06/2017] [Indexed: 11/21/2022] Open
Abstract
The current study aimed to determine the seroprevalence of Trypanosoma cruzi infection in Sucre State, Venezuela, and its association with epidemiological risk factors. The cluster sampling design allowed selecting 96 villages and 576 dwellings in the State's 15 municipalities. A total of 2,212 serum samples were analyzed by ELISA, HAI, and IFI. Seroprevalence in Sucre State was 3.12%. Risk factors associated with T. cruzi infection were: accumulated garbage, flooring and wall materials, type of dwelling, living in a house with wattle and daub walls and/or straw roofing, living in a house with risky walls and roofing, risky buildings and wattle and daub outbuildings, poultry inside the human dwelling, and presence of firewood. Infection was associated with individual age, and three seropositive cases were found in individuals less than 15 years of age. Sucre State has epidemiological factors that favor the risk of acquiring T. cruzi infection.
Collapse
Affiliation(s)
| | - Mariolga Berrizbeitia
- Postgrado en Biología Aplicada, Universidad de Oriente, Cumaná, Venezuela.,Instituto de Investigaciones en Biomedicina y Ciencias Aplicadas, Universidad de Oriente, Cumaná, Venezuela
| | - Jessicca Rodríguez
- Postgrado en Biología Aplicada, Universidad de Oriente, Cumaná, Venezuela
| | | | - Ana Cáceres
- Facultad de Ciencias, Universidad de Los Andes, Mérida, Venezuela
| | | |
Collapse
|
13
|
ACOSTA NIDIA, LÓPEZ ELSA, LEWIS MICHAELD, LLEWELLYN MARTINS, GÓMEZ ANA, ROMÁN FABIOLA, MILES MICHAELA, YEO MATTHEW. Hosts and vectors of Trypanosoma cruzi discrete typing units in the Chagas disease endemic region of the Paraguayan Chaco. Parasitology 2017; 144:884-898. [PMID: 28179034 PMCID: PMC5471830 DOI: 10.1017/s0031182016002663] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2016] [Revised: 12/16/2016] [Accepted: 12/19/2016] [Indexed: 12/29/2022]
Abstract
Active Trypanosoma cruzi transmission persists in the Gran Chaco region, which is considered hyperendemic for Chagas disease. Understanding domestic and sylvatic transmission cycles and therefore the relationship between vectors and mammalian hosts is crucial to designing and implementing improved effective control strategies. Here we describe the species of triatomine vectors and the sylvatic mammal reservoirs of T. cruzi, in different localities of the Paraguayan and Bolivian Chaco. We identify the T. cruzi genotypes discrete typing units (DTUs) and provide a map of their geographical distribution. A total of 1044 triatomines and 138 sylvatic mammals were captured. Five per cent of the triatomines were microscopically positive for T. cruzi (55 Triatoma infestans from Paraguay and one sylvatic Triatoma guasayana from Bolivia) and 17 animals (12·3%) comprising eight of 28 (28·5%) Dasypus novemcinctus, four of 27 (14·8%) Euphractus sexcinctus, three of 64 (4·7%) Chaetophractus spp. and two of 14 (14·3%) Didelphis albiventris. The most common DTU infecting domestic triatomine bugs was TcV (64%), followed by TcVI (28%), TcII (6·5%) and TcIII (1·5%). TcIII was overwhelmingly associated with armadillo species. We confirm the primary role of T. infestans in domestic transmission, armadillo species as the principal sylvatic hosts of TcIII, and consider the potential risk of TcIII as an agent of Chagas disease in the Chaco.
Collapse
Affiliation(s)
- NIDIA ACOSTA
- Departamento de Medicina Tropical, Instituto de Investigaciones en Ciencias de la Salud, Universidad Nacional de Asunción – UNA, San Lorenzo CP 2160, Paraguay
| | - ELSA LÓPEZ
- Departamento de Medicina Tropical, Instituto de Investigaciones en Ciencias de la Salud, Universidad Nacional de Asunción – UNA, San Lorenzo CP 2160, Paraguay
| | - MICHAEL D. LEWIS
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - MARTIN S. LLEWELLYN
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - ANA GÓMEZ
- Centro para el Desarrollo de la Investigación Científica (CEDIC)/Díaz Gill Medicina Laboratorial/Fundación Moisés Bertoni, Asunción, Paraguay
| | - FABIOLA ROMÁN
- Centro para el Desarrollo de la Investigación Científica (CEDIC)/Díaz Gill Medicina Laboratorial/Fundación Moisés Bertoni, Asunción, Paraguay
| | - MICHAEL A. MILES
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| | - MATTHEW YEO
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT, UK
| |
Collapse
|
14
|
Levy MZ, Tustin A, Castillo-Neyra R, Mabud TS, Levy K, Barbu CM, Quispe-Machaca VR, Ancca-Juarez J, Borrini-Mayori K, Naquira-Velarde C, Ostfeld RS. Bottlenecks in domestic animal populations can facilitate the emergence of Trypanosoma cruzi, the aetiological agent of Chagas disease. Proc Biol Sci 2016; 282:rspb.2014.2807. [PMID: 26085582 DOI: 10.1098/rspb.2014.2807] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Faeces-mediated transmission of Trypanosoma cruzi (the aetiological agent of Chagas disease) by triatomine insects is extremely inefficient. Still, the parasite emerges frequently, and has infected millions of people and domestic animals. We synthesize here the results of field and laboratory studies of T. cruzi transmission conducted in and around Arequipa, Peru. We document the repeated occurrence of large colonies of triatomine bugs (more than 1000) with very high infection prevalence (more than 85%). By inoculating guinea pigs, an important reservoir of T. cruzi in Peru, and feeding triatomine bugs on them weekly, we demonstrate that, while most animals quickly control parasitaemia, a subset of animals remains highly infectious to vectors for many months. However, we argue that the presence of these persistently infectious hosts is insufficient to explain the observed prevalence of T. cruzi in vector colonies. We posit that seasonal rains, leading to a fluctuation in the price of guinea pig food (alfalfa), leading to annual guinea pig roasts, leading to a concentration of vectors on a small subpopulation of animals maintained for reproduction, can propel T. cruzi through vector colonies and create a considerable force of infection for a pathogen whose transmission might otherwise fizzle out.
Collapse
Affiliation(s)
- Michael Z Levy
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA Universidad Peruana Cayetano Heredia/University of Pennsylvania Chagas Disease Field Laboratory, Arequipa, Peru
| | - Aaron Tustin
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ricardo Castillo-Neyra
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA Universidad Peruana Cayetano Heredia/University of Pennsylvania Chagas Disease Field Laboratory, Arequipa, Peru
| | - Tarub S Mabud
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Katelyn Levy
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Corentin M Barbu
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA Universidad Peruana Cayetano Heredia/University of Pennsylvania Chagas Disease Field Laboratory, Arequipa, Peru
| | - Victor R Quispe-Machaca
- Universidad Peruana Cayetano Heredia/University of Pennsylvania Chagas Disease Field Laboratory, Arequipa, Peru
| | - Jenny Ancca-Juarez
- Universidad Peruana Cayetano Heredia/University of Pennsylvania Chagas Disease Field Laboratory, Arequipa, Peru
| | - Katty Borrini-Mayori
- Universidad Peruana Cayetano Heredia/University of Pennsylvania Chagas Disease Field Laboratory, Arequipa, Peru
| | - Cesar Naquira-Velarde
- Universidad Peruana Cayetano Heredia/University of Pennsylvania Chagas Disease Field Laboratory, Arequipa, Peru
| | | | | |
Collapse
|
15
|
Gürtler RE, Cardinal MV. Reservoir host competence and the role of domestic and commensal hosts in the transmission of Trypanosoma cruzi. Acta Trop 2015; 151:32-50. [PMID: 26051910 DOI: 10.1016/j.actatropica.2015.05.029] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Revised: 05/25/2015] [Accepted: 05/31/2015] [Indexed: 12/30/2022]
Abstract
We review the epidemiological role of domestic and commensal hosts of Trypanosoma cruzi using a quantitative approach, and compiled >400 reports on their natural infection. We link the theory underlying simple mathematical models of vector-borne parasite transmission to the types of evidence used for reservoir host identification: mean duration of infectious life; host infection and infectiousness; and host-vector contact. The infectiousness of dogs or cats most frequently exceeded that of humans. The host-feeding patterns of major vectors showed wide variability among and within triatomine species related to their opportunistic behavior and variable ecological, biological and social contexts. The evidence shows that dogs, cats, commensal rodents and domesticated guinea pigs are able to maintain T. cruzi in the absence of any other host species. They play key roles as amplifying hosts and sources of T. cruzi in many (peri)domestic transmission cycles covering a broad diversity of ecoregions, ecotopes and triatomine species: no other domestic animal plays that role. Dogs comply with the desirable attributes of natural sentinels and sometimes were a point of entry of sylvatic parasite strains. The controversies on the role of cats and other hosts illustrate the issues that hamper assessing the relative importance of reservoir hosts on the basis of fragmentary evidence. We provide various study cases of how eco-epidemiological and genetic-marker evidence helped to unravel transmission cycles and identify the implicated hosts. Keeping dogs, cats and rodents out of human sleeping quarters and reducing their exposure to triatomine bugs are predicted to strongly reduce transmission risks.
Collapse
Affiliation(s)
- Ricardo E Gürtler
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina.
| | - M V Cardinal
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| |
Collapse
|
16
|
The Burden of Chagas Disease: Estimates and Challenges. Glob Heart 2015; 10:139-44. [DOI: 10.1016/j.gheart.2015.06.001] [Citation(s) in RCA: 118] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 06/04/2015] [Indexed: 11/20/2022] Open
|
17
|
Castillo-Neyra R, Chou Chu L, Quispe-Machaca V, Ancca-Juarez J, Malaga Chavez FS, Bastos Mazuelos M, Naquira C, Bern C, Gilman RH, Levy MZ. The potential of canine sentinels for reemerging Trypanosoma cruzi transmission. Prev Vet Med 2015; 120:349-56. [PMID: 25962956 DOI: 10.1016/j.prevetmed.2015.04.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 03/23/2015] [Accepted: 04/22/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Chagas disease, a vector-borne disease transmitted by triatomine bugs and caused by the parasite Trypanosoma cruzi, affects millions of people in the Americas. In Arequipa, Peru, indoor residual insecticide spraying campaigns are routinely conducted to eliminate Triatoma infestans, the only vector in this area. Following insecticide spraying, there is risk of vector return and reinitiation of parasite transmission. Dogs are important reservoirs of T. cruzi and may play a role in reinitiating transmission in previously sprayed areas. Dogs may also serve as indicators of reemerging transmission. METHODS We conducted a cross-sectional serological screening to detect T. cruzi antibodies in dogs, in conjunction with an entomological vector collection survey at the household level, in a disease endemic area that had been treated with insecticide 13 years prior. Spatial clustering of infected animals and vectors was assessed using Ripley's K statistic, and the odds of being seropositive for dogs proximate to infected colonies was estimated with multivariate logistic regression. RESULTS There were 106 triatomine-infested houses (41.1%), and 45 houses infested with T. cruzi-infected triatomine insects (17.4%). Canine seroprevalence in the area was 12.3% (n=154); all seropositive dogs were 9 months old or older. We observed clustering of vectors carrying the parasite, but no clustering of seropositive dogs. The age- and sex-adjusted odds ratio between seropositivity to T. cruzi and proximity to an infected triatomine (≤50m) was 5.67 (95% CI: 1.12-28.74; p=0.036). CONCLUSIONS Targeted control of reemerging transmission can be achieved by improved understanding of T. cruzi in canine populations. Our results suggest that dogs may be useful sentinels to detect re-initiation of transmission following insecticide treatment. Integration of canine T. cruzi blood sampling into existing interventions for zoonotic disease control (e.g., rabies vaccination programs) can be an effective method of increasing surveillance and improving understanding of disease distribution.
Collapse
Affiliation(s)
- Ricardo Castillo-Neyra
- Center for Clinical Epidemiology & Biostatistics - Department of Biostatistics & Epidemiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA; Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru.
| | - Lily Chou Chu
- Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | - Jenny Ancca-Juarez
- Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | | | | | - Cesar Naquira
- Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Caryn Bern
- School of Medicine, University of California, San Francisco, CA, USA
| | - Robert H Gilman
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | - Michael Z Levy
- Center for Clinical Epidemiology & Biostatistics - Department of Biostatistics & Epidemiology, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA.
| |
Collapse
|
18
|
Gaspe MS, Provecho YM, Cardinal MV, del Pilar Fernández M, Gürtler RE. Ecological and sociodemographic determinants of house infestation by Triatoma infestans in indigenous communities of the Argentine Chaco. PLoS Negl Trop Dis 2015; 9:e0003614. [PMID: 25785439 PMCID: PMC4364707 DOI: 10.1371/journal.pntd.0003614] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Accepted: 02/11/2015] [Indexed: 12/02/2022] Open
Abstract
BACKGROUND The Gran Chaco ecoregion, a hotspot for Chagas and other neglected tropical diseases, is home to >20 indigenous peoples. Our objective was to identify the main ecological and sociodemographic determinants of house infestation and abundance of Triatoma infestans in traditional Qom populations including a Creole minority in Pampa del Indio, northeastern Argentina. METHODS A cross-sectional survey determined house infestation by timed-manual searches with a dislodging aerosol in 386 inhabited houses and administered questionnaires on selected variables before full-coverage insecticide spraying and annual vector surveillance. We fitted generalized linear models to two global models of domestic infestation and bug abundance, and estimated coefficients via multimodel inference with model averaging. PRINCIPAL FINDINGS Most Qom households were larger and lived in small-sized, recently-built, precarious houses with fewer peridomestic structures, and fewer livestock and poultry than Creoles'. Qom households had lower educational level and unexpectedly high residential mobility. House infestation (31.9%) was much lower than expected from lack of recent insecticide spraying campaigns and was spatially aggregated. Nearly half of the infested houses examined had infected vectors. Qom households had higher prevalence of domestic infestation (29.2%) than Creoles' (10.0%), although there is large uncertainty around the adjusted OR. Factors with high relative importance for domestic infestation and/or bug abundance were refuge availability, distance to the nearest infested house, domestic insecticide use, indoor presence of poultry, residential overcrowding, and household educational level. CONCLUSIONS AND SIGNIFICANCE Our study highlights the importance of sociodemographic determinants of domestic infestation such as overcrowding, education and proximity to the nearest infested house, and corroborates the role of refuge availability, domestic use of insecticides and household size. These factors may be used for designing improved interventions for sustainable disease control and risk stratification. Housing instability, household mobility and migration patterns are key to understanding the process of house (re)infestation in the Gran Chaco.
Collapse
Affiliation(s)
- M. Sol Gaspe
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| | - Yael M. Provecho
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| | - M. Victoria Cardinal
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| | - M. del Pilar Fernández
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| | - Ricardo E. Gürtler
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| |
Collapse
|
19
|
Moudy RM, Michaels S, Jameson SB, Londono B, Lopez V, Caillouet KA, Hallmark CJ, Davis JK, Foppa IM, Dorn PL, Wesson DM. Factors associated with peridomestic Triatoma sanguisuga (Hemiptera: Reduviidae) presence in southeastern Louisiana. JOURNAL OF MEDICAL ENTOMOLOGY 2014; 51:1043-1050. [PMID: 25276935 DOI: 10.1603/me13234] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Although rare, there have been isolated reports of autochthonous transmission of Trypanosoma cruzi Chagas in the United States. In June 2006, a human case of domestically transmitted T. cruzi was identified in southern Louisiana. To examine the localized risk of human T. cruzi infection in the area surrounding the initial human case, environmental surveys of households in the area and a serological survey of the residents were performed between September 2008 and November 2009. Human T. cruzi infection was determined using a rapid antigen field test, followed by confirmatory enzyme-linked immunosorbent assay testing in the laboratory. A perimeter search of each participating residence for Triatoma sanguisuga (LeConte), the predominant local triatomine species, was also performed. No participating individuals were positive for antibodies against T. cruzi; however, high levels of T. cruzi infection (62.4%) were detected in collected T. sanguisuga. Households with T. sanguisuga presence were less likely to use air conditioning, and more likely to have either chickens or cats on the property. While the human risk for T cruzi infection in southeastern Louisiana is low, a high prevalence of infected T. sanguisuga does indicate a substantial latent risk for T. cruzi peridomestic transmission. Further examination of the behavior and ecology of T. sanguisuga in the region will assist in refining local T. cruzi risk associations.
Collapse
|
20
|
Gürtler RE, Cecere MC, Vázquez-Prokopec GM, Ceballos LA, Gurevitz JM, Fernández MDP, Kitron U, Cohen JE. Domestic animal hosts strongly influence human-feeding rates of the Chagas disease vector Triatoma infestans in Argentina. PLoS Negl Trop Dis 2014; 8:e2894. [PMID: 24852606 PMCID: PMC4037315 DOI: 10.1371/journal.pntd.0002894] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Accepted: 04/14/2014] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND The host species composition in a household and their relative availability affect the host-feeding choices of blood-sucking insects and parasite transmission risks. We investigated four hypotheses regarding factors that affect blood-feeding rates, proportion of human-fed bugs (human blood index), and daily human-feeding rates of Triatoma infestans, the main vector of Chagas disease. METHODS A cross-sectional survey collected triatomines in human sleeping quarters (domiciles) of 49 of 270 rural houses in northwestern Argentina. We developed an improved way of estimating the human-feeding rate of domestic T. infestans populations. We fitted generalized linear mixed-effects models to a global model with six explanatory variables (chicken blood index, dog blood index, bug stage, numbers of human residents, bug abundance, and maximum temperature during the night preceding bug catch) and three response variables (daily blood-feeding rate, human blood index, and daily human-feeding rate). Coefficients were estimated via multimodel inference with model averaging. FINDINGS Median blood-feeding intervals per late-stage bug were 4.1 days, with large variations among households. The main bloodmeal sources were humans (68%), chickens (22%), and dogs (9%). Blood-feeding rates decreased with increases in the chicken blood index. Both the human blood index and daily human-feeding rate decreased substantially with increasing proportions of chicken- or dog-fed bugs, or the presence of chickens indoors. Improved calculations estimated the mean daily human-feeding rate per late-stage bug at 0.231 (95% confidence interval, 0.157-0.305). CONCLUSIONS AND SIGNIFICANCE Based on the changing availability of chickens in domiciles during spring-summer and the much larger infectivity of dogs compared with humans, we infer that the net effects of chickens in the presence of transmission-competent hosts may be more adequately described by zoopotentiation than by zooprophylaxis. Domestic animals in domiciles profoundly affect the host-feeding choices, human-vector contact rates and parasite transmission predicted by a model based on these estimates.
Collapse
Affiliation(s)
- Ricardo E. Gürtler
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
- * E-mail:
| | - María C. Cecere
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| | - Gonzalo M. Vázquez-Prokopec
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
- Department of Environmental Studies, Emory University, Atlanta, Georgia, United States of America
| | - Leonardo A. Ceballos
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| | - Juan M. Gurevitz
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| | - María del Pilar Fernández
- Laboratory of Eco-Epidemiology, Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires-IEGEBA (CONICET-UBA), Buenos Aires, Argentina
| | - Uriel Kitron
- Department of Environmental Studies, Emory University, Atlanta, Georgia, United States of America
| | - Joel E. Cohen
- Laboratory of Populations, Rockefeller and Columbia Universities, New York, New York, United States of America
| |
Collapse
|
21
|
Dorňáková V, Salazar-Sanchez R, Borrini-Mayori K, Carrion-Navarro O, Levy MZ, Schaub GA, Schwarz A. Characterization of guinea pig antibody responses to salivary proteins of Triatoma infestans for the development of a triatomine exposure marker. PLoS Negl Trop Dis 2014; 8:e2783. [PMID: 24699441 PMCID: PMC3974673 DOI: 10.1371/journal.pntd.0002783] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 02/24/2014] [Indexed: 11/22/2022] Open
Abstract
Background Salivary proteins of Triatoma infestans elicit humoral immune responses in their vertebrate hosts. These immune responses indicate exposure to triatomines and thus can be a useful epidemiological tool to estimate triatomine infestation. In the present study, we analyzed antibody responses of guinea pigs to salivary antigens of different developmental stages of four T. infestans strains originating from domestic and/or peridomestic habitats in Argentina, Bolivia, Chile and Peru. We aimed to identify developmental stage- and strain-specific salivary antigens as potential markers of T. infestans exposure. Methodology and Principal Findings In SDS-PAGE analysis of salivary proteins of T. infestans the banding pattern differed between developmental stages and strains of triatomines. Phenograms constructed from the salivary profiles separated nymphal instars, especially the 5th instar, from adults. To analyze the influence of stage- and strain-specific differences in T. infestans saliva on the antibody response of guinea pigs, twenty-one guinea pigs were exposed to 5th instar nymphs and/or adults of different T. infestans strains. Western blot analyses using sera of exposed guinea pigs revealed stage- and strain-specific variations in the humoral response of animals. In total, 27 and 17 different salivary proteins reacted with guinea pig sera using IgG and IgM antibodies, respectively. Despite all variations of recognized salivary antigens, an antigen of 35 kDa reacted with sera of almost all challenged guinea pigs. Conclusion Salivary antigens are increasingly considered as an epidemiological tool to measure exposure to hematophagous arthropods, but developmental stage- and strain-specific variations in the saliva composition and the respective differences of immunogenicity are often neglected. Thus, the development of a triatomine exposure marker for surveillance studies after triatomine control campaigns requires detailed investigations. Our study resulted in the identification of a potential antigen as useful marker of T. infestans exposure. Chagas disease is caused by the protozoan parasite Trypanosoma cruzi, and currently affects approximately 8 million people in Latin American countries. Although vector control campaigns against the most effective Chagas disease vector, Triatoma infestans, have been highly successful, T. infestans is re-establishing in once-endemic regions. To monitor re-establishing triatomines, new epidemiological tools are needed. Antibody responses of hosts to triatomine salivary proteins represent a promising tool to detect biting bugs, and highly immunogenic salivary antigens may be used as markers of triatomine exposure. Therefore, we analyzed the antibody response of guinea pigs, common peridomestic hosts of T. infestans, to salivary proteins of nymphs and adults of four different T. infestans strains from Argentina, Bolivia, Chile and Peru. Developmental stage- and strain-specific proteins in the saliva of T. infestans influenced the antibody response of guinea pigs, and different salivary antigens were recognized by guinea pig sera. Despite the variations of immunogenic salivary antigens, a 35 kDa antigen was recognized by almost all guinea pig sera and this antigen may be a useful marker of T. infestans exposure.
Collapse
Affiliation(s)
- Veronika Dorňáková
- Institute of Parasitology, Biology Centre of the Academy of Sciences of Czech Republic, Ceske Budejovice, Czech Republic
- Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | | | | | | | - Michael Z. Levy
- Universidad Peruana Cayetano Heredia, Sede de Arequipa, Arequipa, Peru
- Department of Biostatistics and Epidemiology, Center for Clinical Epidemiology and Biostatistics, School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Günter A. Schaub
- Zoology/Parasitology Group, Ruhr-University Bochum, Bochum, Germany
| | - Alexandra Schwarz
- Institute of Parasitology, Biology Centre of the Academy of Sciences of Czech Republic, Ceske Budejovice, Czech Republic
- * E-mail:
| |
Collapse
|
22
|
Nouvellet P, Dumonteil E, Gourbière S. The improbable transmission of Trypanosoma cruzi to human: the missing link in the dynamics and control of Chagas disease. PLoS Negl Trop Dis 2013; 7:e2505. [PMID: 24244766 PMCID: PMC3820721 DOI: 10.1371/journal.pntd.0002505] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 09/16/2013] [Indexed: 01/13/2023] Open
Abstract
Chagas disease has a major impact on human health in Latin America and is becoming of global concern due to international migrations. Trypanosoma cruzi, the etiological agent of the disease, is one of the rare human parasites transmitted by the feces of its vector, as it is unable to reach the salivary gland of the insect. This stercorarian transmission is notoriously poorly understood, despite its crucial role in the ecology and evolution of the pathogen and the disease. The objective of this study was to quantify the probability of T. cruzi vectorial transmission to humans, and to use such an estimate to predict human prevalence from entomological data. We developed several models of T. cruzi transmission to estimate the probability of transmission from vector to host. Using datasets from the literature, we estimated the probability of transmission per contact with an infected triatomine to be 5.8 × 10(-4) (95%CI: [2.6 ; 11.0] × 10(-4)). This estimate was consistent across triatomine species, robust to variations in other parameters, and corresponded to 900-4,000 contacts per case. Our models subsequently allowed predicting human prevalence from vector abundance and infection rate in 7/10 independent datasets covering various triatomine species and epidemiological situations. This low probability of T. cruzi transmission reflected well the complex and unlikely mechanism of transmission via insect feces, and allowed predicting human prevalence from basic entomological data. Although a proof of principle study would now be valuable to validate our models' predictive ability in an even broader range of entomological and ecological settings, our quantitative estimate could allow switching the evaluation of disease risk and vector control program from purely entomological indexes to parasitological measures, as commonly done for other major vector borne diseases. This might lead to different quantitative perspectives as these indexes are well known not to be proportional one to another.
Collapse
Affiliation(s)
- Pierre Nouvellet
- Laboratorio de Parasitología, Centro de Investigaciones Regionales "Dr. Hideyo Noguchi", Universidad Autónoma de Yucatán, Mérida, Yucatán, Mexico ; EA 4218 UPVD 'Institut de Modélisation et d'Analyses en Géo-Environnement et Santé', Université de Perpignan Via Domitia, Perpignan, France ; Medical Research Council Centre for Outbreak Analysis and Modelling, Department of Infectious Disease Epidemiology, Imperial College London, London, United Kingdom
| | | | | |
Collapse
|
23
|
Samuels AM, Clark EH, Galdos-Cardenas G, Wiegand RE, Ferrufino L, Menacho S, Gil J, Spicer J, Budde J, Levy MZ, Bozo RW, Gilman RH, Bern C. Epidemiology of and impact of insecticide spraying on Chagas disease in communities in the Bolivian Chaco. PLoS Negl Trop Dis 2013; 7:e2358. [PMID: 23936581 PMCID: PMC3731239 DOI: 10.1371/journal.pntd.0002358] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Accepted: 06/27/2013] [Indexed: 12/05/2022] Open
Abstract
Background Chagas disease control campaigns relying upon residual insecticide spraying have been successful in many Southern American countries. However, in some areas, rapid reinfestation and recrudescence of transmission have occurred. Methodology/Principal Findings We conducted a cross-sectional survey in the Bolivian Chaco to evaluate prevalence of and risk factors for T. cruzi infection 11 years after two rounds of blanket insecticide application. We used a cubic B-spline model to estimate change in force of infection over time based on age-specific seroprevalence data. Overall T. cruzi seroprevalence was 51.7%. The prevalence was 19.8% among children 2–15, 72.7% among those 15–30 and 97.1% among participants older than 30 years. Based on the model, the estimated annual force of infection was 4.3% over the two years before the first blanket spray in 2000 and fell to 0.4% for 2001–2002. The estimated annual force of infection for 2004–2005, the 2 year period following the second blanket spray, was 4.6%. However, the 95% bootstrap confidence intervals overlap for all of these estimates. In a multivariable model, only sleeping in a structure with cracks in the walls (aOR = 2.35; 95% CI = 1.15–4.78), age and village of residence were associated with infection. Conclusions/Significance As in other areas in the Chaco, we found an extremely high prevalence of Chagas disease. Despite evidence that blanket insecticide application in 2000 may have decreased the force of infection, active transmission is ongoing. Continued spraying vigilance, infestation surveillance, and systematic household improvements are necessary to disrupt and sustain interruption of infection transmission. Despite significant gains in the reduction of the burden of Chagas disease in many South American countries, active transmission and significant burden remain in areas such as the Gran Chaco. High initial vector density, poor housing material, peridomestic infestation, insecticide resistance, and a lack of systematic insecticide spraying and vector surveillance have previously been incriminated for failure to interrupt and sustain interruption of transmission. We conducted a census, seroprevalence, and epidemiologic study in a rural area in the Bolivian Chaco. The prevalence of infection was almost 20% in children and over 80% in adults. We estimated the intensity of transmission over time based on infection prevalence by age. We found that after the first spray program, transmission appeared to fall transiently but then increased again quickly. Sleeping in a structure with cracks in the walls, age and village of residence were associated with increased likelihood of infection. These findings suggest that consistently repeated systematic spraying campaigns accompanied by housing improvements are necessary to interrupt and sustain interruption of vector-borne transmission.
Collapse
Affiliation(s)
- Aaron M. Samuels
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Eva H. Clark
- University of Alabama School of Medicine, Birmingham, Alabama, United States of America
| | - Gerson Galdos-Cardenas
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
| | - Ryan E. Wiegand
- Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | | | | | - Jose Gil
- Instituto de Investigaciones en Enfermedades Tropicales, Universidad Nacional de Salta, Salta, Argentina
| | - Jennifer Spicer
- Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Julia Budde
- Emory University School of Medicine, Atlanta, Georgia, United States of America
| | - Michael Z. Levy
- University of Pennsylvania, Philadelphia, Pennsylvania United States of America
| | | | - Robert H. Gilman
- Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- * E-mail:
| | - Caryn Bern
- Global Health Sciences, University of California San Francisco, San Francisco, California, United States of America
| | | |
Collapse
|
24
|
Quijano-Hernández IA, Castro-Barcena A, Aparicio-Burgos E, Barbosa-Mireles MA, Cruz-Chan JV, Vázquez-Chagoyán JC, Bolio-González ME, Dumonteil E. Evaluation of clinical and immunopathological features of different infective doses of Trypanosoma cruzi in dogs during the acute phase. ScientificWorldJournal 2012; 2012:635169. [PMID: 22547991 PMCID: PMC3323355 DOI: 10.1100/2012/635169] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2011] [Accepted: 11/28/2011] [Indexed: 11/17/2022] Open
Abstract
Infection with Trypanosoma cruzi is a major risk in Latin America, and dogs are believed to be good models for evaluating Chagas disease. Here, we evaluated the clinical and immunopathological alterations developed by mongrel dogs experimentally infected with different infective doses (2,000, 20,000, and 200,000 metacyclic trypomastigotes of Sylvio X10/4 strain kg−1 via intraperitoneal). Clinical and electrocardiographic parameters, as well as antibody production and pathologic lesions were evaluated. All three doses of this strain of T. cruzi induced a similar pattern of infection characterized by cardiac arrhythmias and severe and diffuse myocarditis. Specific anti-T. cruzi IgG indicated seroconversion by day 14 after infection, and IgG levels increased during the period of evaluation. Mortality was observed only in dogs infected with the medium or high parasite doses, but not in the group infected with a low dose of 2,000 parasites kg−1. Infection with a low dose of parasites provides an excellent nonlethal model to evaluate the immunopathology of the acute disease in dogs infected with the Sylvio X10/4 strain of T. cruzi.
Collapse
Affiliation(s)
- Israel A Quijano-Hernández
- Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de México, Cerrillo Piedras Blancas s/n, 50200 Toluca, Mexico.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Bonfante-Cabarcas R, Rodríguez-Bonfante C, Vielma BO, García D, Saldivia AM, Aldana E, Curvelo JLC. [Seroprevalence for Trypanosoma cruzi infection and associated factors in an endemic area of Venezuela]. CAD SAUDE PUBLICA 2012; 27:1917-29. [PMID: 22031196 DOI: 10.1590/s0102-311x2011001000005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 07/06/2011] [Indexed: 11/22/2022] Open
Abstract
This study investigated risk factors associated with positive serological status for Trypanosoma cruzi antibodies in 26 rural communities including 905 households, 2,156 humans, and 333 dogs in Lara State, Venezuela. Serology was performed with ELISA and MABA. Data were obtained from entomological, demographic, and clinical surveys. Risk factors were determined through binary logistic regression. Seroprevalence was 7.24% in humans and 6.9% in canines. Positive serological status was positively associated with the Rhodnius prolixus vector, age, maternal history of Chagas disease, tobacco chewing, presence of mammals and birds in the household, household disarray, mud-and-wattle outbuildings, and animal nests and burrows in the peridomicile, and negatively associated with tobacco and alcohol consumption, history of cancer, and storage deposits in the peridomile. In conclusion, Chagas disease in this rural area is an old phenomenon transmitted by R. prolixus or by the transplacental route, associated with socio-cultural habits related to poverty, sylvatic surroundings, and the host's medical history.
Collapse
|
26
|
Dealing with initial inconclusive serological results for chronic Chagas disease in clinical practice. Eur J Clin Microbiol Infect Dis 2011; 31:965-74. [DOI: 10.1007/s10096-011-1393-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 08/18/2011] [Indexed: 11/27/2022]
|
27
|
Barbabosa-Pliego A, Gil PC, Hernández DO, Aparicio-Burgos JE, de Oca-Jiménez RM, Martínez-Castañeda JS, Ochoa-García L, Guzmán-Bracho C, Estrada-Franco JG, Garg NJ, Chagoyán JCV. Prevalence ofTrypanosoma cruziin Dogs (Canis familiaris) and Triatomines During 2008 in a Sanitary Region of the State of Mexico, Mexico. Vector Borne Zoonotic Dis 2011; 11:151-6. [DOI: 10.1089/vbz.2009.0163] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Alberto Barbabosa-Pliego
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia de la, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - Pablo Campos Gil
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia de la, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - Dora Olivares Hernández
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia de la, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - José E. Aparicio-Burgos
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia de la, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - Roberto Montes de Oca-Jiménez
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia de la, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - José Simón Martínez-Castañeda
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia de la, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - Laucel Ochoa-García
- Laboratorio Estatal de Salud Pública del, Instituto Salud del Estado de México, Tollocan S/N Col Moderna de la Cruz, Toluca, México
| | - Carmen Guzmán-Bracho
- Instituto de Diagnóstico y Referencia Epidemiológicas, Secretaria de Salud Prolongación de Carpio 470 Col. Santo Tomás Delegación Miguel Hidalgo 11340 México, D.F
| | - José G. Estrada-Franco
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas
- Universidad Autonóma de Chiapas, Tapachula, Chiapas, Mexico
| | - Nisha Jain Garg
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas
| | - Juan Carlos Vázquez Chagoyán
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia de la, Universidad Autónoma del Estado de México, Toluca, Mexico
| |
Collapse
|
28
|
Bowman NM, Kawai V, Gilman RH, Bocangel C, Galdos-Cardenas G, Cabrera L, Levy MZ, Cornejo del Carpio JG, Delgado F, Rosenthal L, Pinedo-Cancino VV, Steurer F, Seitz AE, Maguire JH, Bern C. Autonomic dysfunction and risk factors associated with Trypanosoma cruzi infection among children in Arequipa, Peru. Am J Trop Med Hyg 2011; 84:85-90. [PMID: 21212207 PMCID: PMC3005523 DOI: 10.4269/ajtmh.2011.10-0303] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Accepted: 08/30/2010] [Indexed: 11/07/2022] Open
Abstract
Chagas disease affects an estimated 8 million people in Latin America. Infected individuals have 20-30% lifetime risk of developing cardiomyopathy, but more subtle changes in autonomic responses may be more frequent. We conducted a matched case-control study of children in Arequipa, Peru, where triatomine infestation and Trypanosoma cruzi infection are emerging problems. We collected data on home environment, history, physical examination, electrocardiogram, and autonomic testing. Signs of triatomine infestation and/or animals sleeping in the child's room and household members with Chagas disease were associated with increased infection risk. Electrocardiogram findings did not differ between cases and controls. However, compared with control children, infected children had blunted autonomic responses by three different measures, the Valsalva maneuver, the cold pressor test, and the orthostatic test. T. cruzi-infected children show autonomic dysfunction, although the prognostic value of this finding is not clear. Sustained vector control programs are essential to decreasing future T. cruzi infections.
Collapse
Affiliation(s)
- Natalie M Bowman
- Division of Infectious Diseases, University of North Carolina-Chapel Hill, Chapel Hill, North Carolina, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Bowman NM, Kawai V, Levy MZ, Cornejo del Carpio JG, Cabrera L, Delgado F, Malaga F, Cordova Benzaquen E, Pinedo VV, Steurer F, Seitz AE, Gilman RH, Bern C. Chagas disease transmission in periurban communities of Arequipa, Peru. Clin Infect Dis 2008; 46:1822-8. [PMID: 18462104 DOI: 10.1086/588299] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
BACKGROUND Chagas disease, caused by Trypanosoma cruzi infection, is an urban problem in Arequipa, Peru, and the epidemiology of Chagas disease is likely to be quite different in this area, compared with in rural zones. METHODS We conducted a serosurvey of 1615 children <18 years old in periurban districts that included hillside shantytowns and slightly more affluent low-lying communities. In addition, 639 adult residents of 1 shantytown were surveyed to provide data across the age spectrum for this community. RESULTS Of 1615 children, 75 (4.7%) were infected with Trypanosoma cruzi. Infection risk increased by 12% per year of age, and children living in hillside shantytowns were 2.5 times as likely to be infected as were those living in lower-lying communities. However, age-prevalence data from 1 shantytown demonstrated that adults were no more likely to be seropositive than were teenagers; the results of maximum likelihood modeling suggest that T. cruzi transmission began in this community <20 years ago. CONCLUSIONS The problem of Chagas disease in periurban settings, such as those around Arequipa, must be addressed to achieve elimination of vector-borne T. cruzi transmission. Identification of infected children, vector-control efforts, and education to avoid modifiable risk factors are necessary to decrease the burden of Chagas disease.
Collapse
Affiliation(s)
- Natalie M Bowman
- Asociación Benéfica Proyectos en Informática, Salud, Medicina y Agricultura, Lima, Peru
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Epidemiological evaluation of Chagas disease in a rural area of southern Bolivia. Trans R Soc Trop Med Hyg 2008; 102:578-84. [DOI: 10.1016/j.trstmh.2008.03.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2008] [Revised: 03/05/2008] [Accepted: 03/06/2008] [Indexed: 11/22/2022] Open
|
31
|
Castillo-Riquelme M, Chalabi Z, Lord J, Guhl F, Campbell-Lendrum D, Davies C, Fox-Rushby J. Modelling geographic variation in the cost-effectiveness of control policies for infectious vector diseases: the example of Chagas disease. JOURNAL OF HEALTH ECONOMICS 2008; 27:405-426. [PMID: 18222556 DOI: 10.1016/j.jhealeco.2007.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2006] [Revised: 04/24/2007] [Accepted: 04/30/2007] [Indexed: 05/25/2023]
Abstract
Few cost-effectiveness analysis (CEA) models have accounted for geographic variation in input parameters. This paper describes a deterministic discrete-time multi-state model to estimate the cost-effectiveness of vector control policies for Chagas disease, where implementation varies according to village characteristics. The model outputs include the total number of new infections, disability adjusted life years (DALYs) incurred, costs of associated healthcare, and total costs of the Ministry of Health's control policy for house surveillance and spraying. Incremental net benefits were estimated to determine Colombian villages in which it is cost-effective to implement the control policy. The robustness of these conclusions was evaluated by deterministic sensitivity analyses. The model should help provide a decision-support system to compare control policies and to allocate resources geographically.
Collapse
|
32
|
Levy MZ, Kawai V, Bowman NM, Waller LA, Cabrera L, Pinedo-Cancino VV, Seitz AE, Steurer FJ, Cornejo del Carpio JG, Cordova-Benzaquen E, Maguire JH, Gilman RH, Bern C. Targeted screening strategies to detect Trypanosoma cruzi infection in children. PLoS Negl Trop Dis 2007; 1:e103. [PMID: 18160979 PMCID: PMC2154390 DOI: 10.1371/journal.pntd.0000103] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2007] [Accepted: 09/12/2007] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Millions of people are infected with Trypanosoma cruzi, the causative agent of Chagas disease in Latin America. Anti-trypanosomal drug therapy can cure infected individuals, but treatment efficacy is highest early in infection. Vector control campaigns disrupt transmission of T. cruzi, but without timely diagnosis, children infected prior to vector control often miss the window of opportunity for effective chemotherapy. METHODS AND FINDINGS We performed a serological survey in children 2-18 years old living in a peri-urban community of Arequipa, Peru, and linked the results to entomologic, spatial and census data gathered during a vector control campaign. 23 of 433 (5.3% [95% CI 3.4-7.9]) children were confirmed seropositive for T. cruzi infection by two methods. Spatial analysis revealed that households with infected children were very tightly clustered within looser clusters of households with parasite-infected vectors. Bayesian hierarchical mixed models, which controlled for clustering of infection, showed that a child's risk of being seropositive increased by 20% per year of age and 4% per vector captured within the child's house. Receiver operator characteristic (ROC) plots of best-fit models suggest that more than 83% of infected children could be identified while testing only 22% of eligible children. CONCLUSIONS We found evidence of spatially-focal vector-borne T. cruzi transmission in peri-urban Arequipa. Ongoing vector control campaigns, in addition to preventing further parasite transmission, facilitate the collection of data essential to identifying children at high risk of T. cruzi infection. Targeted screening strategies could make integration of diagnosis and treatment of children into Chagas disease control programs feasible in lower-resource settings.
Collapse
Affiliation(s)
- Michael Z Levy
- Division of Parasitic Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Gürtler RE. Combining residual insecticide spraying campaigns with targeted detection and specific chemotherapy for Trypanosoma cruzi infection in children. PLoS Negl Trop Dis 2007; 1:e168. [PMID: 18160985 PMCID: PMC2154396 DOI: 10.1371/journal.pntd.0000168] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Ricardo E Gürtler
- Department of Ecology, Genetics and Evolution, Universidad de Buenos Aires, Buenos Aires, Argentina.
| |
Collapse
|
34
|
Gürtler RE, Kitron U, Cecere MC, Segura EL, Cohen JE. Sustainable vector control and management of Chagas disease in the Gran Chaco, Argentina. Proc Natl Acad Sci U S A 2007; 104:16194-9. [PMID: 17913895 PMCID: PMC2042184 DOI: 10.1073/pnas.0700863104] [Citation(s) in RCA: 194] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Indexed: 11/18/2022] Open
Abstract
Chagas disease remains a serious obstacle to health and economic development in Latin America, especially for the rural poor. We report the long-term effects of interventions in rural villages in northern Argentina during 1984-2006. Two community-wide campaigns of residual insecticide spraying immediately and strongly reduced domestic infestation and infection with Trypanosoma cruzi in Triatoma infestans bugs and dogs and more gradually reduced the seroprevalence of children <15 years of age. Because no effective surveillance and control actions followed the first campaign in 1985, transmission resurged in 2-3 years. Renewed interventions in 1992 followed by sustained, supervised, community-based vector control largely suppressed the reestablishment of domestic bug colonies and finally led to the interruption of local human T. cruzi transmission. Human incidence of infection was nearly an order of magnitude higher in peripheral rural areas under pulsed, unsupervised, community-based interventions, where human transmission became apparent in 2000. The sustained, supervised, community-based strategy nearly interrupted domestic transmission to dogs but did not eliminate T. infestans despite the absence of pyrethroid-insecticide resistance. T. infestans persisted in part because of the lack of major changes in housing construction and quality. Sustained community participation grew out of establishing a trusted relationship with the affected communities and the local schools. The process included health promotion and community mobilization, motivation, and supervision in close cooperation with locally nominated leaders.
Collapse
Affiliation(s)
- Ricardo E. Gürtler
- *Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina
| | - Uriel Kitron
- Department of Pathobiology and Center for Zoonoses Research, University of Illinois at Urbana–Champaign, 2001 South Lincoln Avenue, Urbana, IL 61802
| | - M. Carla Cecere
- *Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina
| | - Elsa L. Segura
- Instituto Nacional de Parasitología Dr. Mario Fatala Chaben, Paseo Colón 568, 1032 Buenos Aires, Argentina; and
| | - Joel E. Cohen
- Laboratory of Populations, Rockefeller University and Columbia University, 1230 York Avenue, Box 20, New York, NY 10065-6399
| |
Collapse
|
35
|
Enfermedad de Chagas aguda en Colombia, una entidad poco sospechada. Informe de 10 casos presentados en el periodo 2002 a 2005. BIOMEDICA 2007. [DOI: 10.7705/biomedica.v27i1.244] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
36
|
Black CL, Ocaña S, Riner D, Costales JA, Lascano MS, Davila S, Arcos-Teran L, Seed JR, Grijalva MJ. HOUSEHOLD RISK FACTORS FOR TRYPANOSOMA CRUZI SEROPOSITIVITY IN TWO GEOGRAPHIC REGIONS OF ECUADOR. J Parasitol 2007; 93:12-6. [PMID: 17436937 DOI: 10.1645/ge-899r.1] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Few studies on the relationship between environmental factors and Trypanosoma cruzi transmission have been conducted in Ecuador. We conducted a cross-sectional study of household risk factors for T. cruzi seropositivity in 2 distinct geographical regions of Ecuador. Exposure information was collected via household surveys, and subjects were tested for serological evidence of T. cruzi infection. In total, 3,286 subjects from 997 households were included. In the coastal region, factors associated with seropositivity were living in a house with a palm roof (odds ratio [OR] = 2.63, 95% confidence interval, [1.61. 4.27]), wood walls (OR = 5.75 [2.04, 16.18]), or cane walls (OR = 2.81 11.31, 6.04]), and the presence of firewood in the peridomicile (OR = 2.48 [1.54, 4.01]). Accumulation of trash outside the home was associated with a reduced risk of seropositivity (OR = 0.25 [0.12, 0.51]). In the Andean region, living in a house with adobe walls was the only factor predictive of T. cruzi seropositivity. In conclusion, risk factors for T. cruzi transmission in Ecuador varied by geographic region, probably because of differing behavior of the triatomine vector species in each region. An understanding of the transmission dynamics of T. cruzi in a particular area is necessary for the development of effective Chagas disease control strategies in those areas.
Collapse
Affiliation(s)
- Carla L Black
- Department of Epidemiology, School of Public Health, University of North Carolina, Chapel Hill, North Carolina, 27599, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Levy MZ, Bowman NM, Kawai V, Waller LA, Cornejo del Carpio JG, Cordova Benzaquen E, Gilman RH, Bern C. Periurban Trypanosoma cruzi-infected Triatoma infestans, Arequipa, Peru. Emerg Infect Dis 2006; 12:1345-52. [PMID: 17073082 PMCID: PMC3294737 DOI: 10.3201/eid1209.051662] [Citation(s) in RCA: 85] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Simple interventions may facilitate vector control and prevent periurban transmission of Chagas disease. In Arequipa, Peru, vectorborne transmission of Chagas disease by Triatoma infestans has become an urban problem. We conducted an entomologic survey in a periurban community of Arequipa to identify risk factors for triatomine infestation and determinants of vector population densities. Of 374 households surveyed, triatomines were collected from 194 (52%), and Trypanosoma cruzi–carrying triatomines were collected from 72 (19.3%). Guinea pig pens were more likely than other animal enclosures to be infested and harbored 2.38× as many triatomines. Stacked brick and adobe enclosures were more likely to have triatomines, while wire mesh enclosures were protected against infestation. In human dwellings, only fully stuccoed rooms were protected against infestation. Spatially, households with triatomines were scattered, while households with T. cruzi–infected triatomines were clustered. Keeping small animals in wire mesh cages could facilitate control of T. infestans in this densely populated urban environment.
Collapse
|
38
|
Gürtler RE, Cecere MC, Lauricella MA, Cardinal MV, Kitron U, Cohen JE. Domestic dogs and cats as sources of Trypanosoma cruzi infection in rural northwestern Argentina. Parasitology 2006; 134:69-82. [PMID: 17032467 PMCID: PMC2669415 DOI: 10.1017/s0031182006001259] [Citation(s) in RCA: 174] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2005] [Revised: 04/07/2006] [Accepted: 05/24/2006] [Indexed: 11/06/2022]
Abstract
The reservoir capacity of domestic cats and dogs for Trypanosoma cruzi infection and the host-feeding patterns of domestic Triatoma infestans were assessed longitudinally in 2 infested rural villages in north-western Argentina. A total of 86 dogs and 38 cats was repeatedly examined for T. cruzi infection by serology and/or xenodiagnosis. The composite prevalence of infection in dogs (60%), but not in cats, increased significantly with age and with the domiciliary density of infected T. infestans. Dogs and cats had similarly high forces of infection, prevalence of infectious hosts (41-42%), and infectiousness to bugs at a wide range of infected bug densities. The infectiousness to bugs of seropositive dogs declined significantly with increasing dog age and was highly aggregated. Individual dog infectiousness to bugs was significantly autocorrelated over time. Domestic T. infestans fed on dogs showed higher infection prevalence (49%) than those fed on cats (39%), humans (38%) or chickens (29%) among 1085 bugs examined. The basic reproduction number of T. cruzi in dogs was at least 8.2. Both cats and dogs are epidemiologically important sources of infection for bugs and householders, dogs nearly 3 times more than cats.
Collapse
Affiliation(s)
- R E Gürtler
- Laboratorio de Eco-Epidemiología, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
| | | | | | | | | | | |
Collapse
|
39
|
Estrada-Franco JG, Bhatia V, Diaz-Albiter H, Ochoa-Garcia L, Barbabosa A, Vazquez-Chagoyan JC, Martinez-Perez MA, Guzman-Bracho C, Garg N. Human Trypanosoma cruzi infection and seropositivity in dogs, Mexico. Emerg Infect Dis 2006; 12:624-30. [PMID: 16704811 PMCID: PMC3294681 DOI: 10.3201/eid1204.050450] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Seroanalysis of parasite circulation in dogs can help identify T. cruzi infection in humans. We used 5 diagnostic tests in a cross-sectional investigation of the prevalence of Trypanosoma cruzi in Tejupilco municipality, State of Mexico, Mexico. Our findings showed a substantial prevalence of immunoglobulin G (IgG) and IgM antibodies to T. cruzi in human (n = 293, IgG 2.05%, IgM 5.5%, both 7.1%) and dog (n = 114, IgG 15.8%, IgM 11.4%, both 21%) populations. We also found antibodies to T. cruzi (n = 80, IgG 10%, IgM 15%, both 17.5%) in dogs from Toluca, an area previously considered free of T. cruzi. Our data demonstrate the need for active epidemiologic surveillance programs in these regions. A direct correlation (r2 = 0.955) of seropositivity between humans and dogs suggests that seroanalysis in dogs may help identify the human prevalence of T. cruzi infection in these areas.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Carmen Guzman-Bracho
- Instituto de Diagnostico y Referencia Epidemiologicos Secretaría de Salud, Mexico City, Mexico
| | - Nisha Garg
- University of Texas Medical Branch, Galveston, Texas, USA
| |
Collapse
|
40
|
Ferrer JF, Galligan D, Esteban E, Rey V, Murua A, Gutierrez S, Gonzalez L, Thakuri M, Feldman L, Poiesz B, Jonsson C. Hantavirus infection in people inhabiting a highly endemic region of the Gran Chaco territory, Paraguay: association with Trypanosoma cruzi infection, epidemiological features and haematological characteristics. ANNALS OF TROPICAL MEDICINE AND PARASITOLOGY 2003; 97:269-80. [PMID: 12803858 DOI: 10.1179/000349803235001903] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The seroprevalences of anti-hantavirus antibodies were determined in 712 individuals (551 Indians, 140 Mennonites of German ancestry, and 21 Paraguayans of Spanish ancestry) inhabiting a region of western Paraguay in the Gran Chaco territory of South America. The overall seroprevalence of hantavirus infection among the 712 subjects, who were aged 2-80 years, was 42.7% (45.2% in the Indians and 34.2% in the non-Indians). Of the 672 subjects also checked for antibodies against Trypanosoma cruzi, 226 (33.6%) were seropositive for this protozoan parasite. The results of a multivariate regression analysis indicated that, after adjusting for age, sex, setting of residence (rural/urban) and infection with the human T-cell leukaemia/lymphoma virus type II (HTLV-II), a T. cruzi-seropositive individual was 1.73 times more likely to be hantavirus seropositive than a T. cruzi-seronegative individual. Living in a rural setting increased the risk of being hantavirus seropositive 2.17-fold. In both the Indians and non-Indian subpopulations, hantavirus seroprevalence increased with age in both sexes, but only in the non-Indian supopulation was this increase significantly greater in males than in females. Hantavirus seropositivity was significantly associated with thrombocytosis, even after adjusting for the relevant confounders.
Collapse
Affiliation(s)
- J F Ferrer
- New Bolton Center, University of Pennsylvania, 382 West Street Road, Kennett Square, PA 19348, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
41
|
Abstract
Trypanosoma cruzi, the causative agent of Chagas disease, infects 10-18 million people and may be transmitted to the newborn. Using various data sources, we estimated that nearly 850 congenital cases occurred in Argentina in 1993, or 6.3 expected cases per each reported case in 1994 and in 1994-2001. The congenital transmission of T. cruzi constitutes a sizeable public health problem in the region.
Collapse
Affiliation(s)
- Ricardo E Gürtler
- Departamento de Ecología, Genética y Evolución, Universidad de Buenos Aires, Buenos Aires, Argentina.
| | | | | |
Collapse
|
42
|
Cecere MC, Gürtler RE, Canale DM, Chuit R, Cohen JE. Effects of partial housing improvement and insecticide spraying on the reinfestation dynamics of Triatoma infestans in rural northwestern Argentina. Acta Trop 2002; 84:101-16. [PMID: 12429427 DOI: 10.1016/s0001-706x(02)00183-3] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The long-term effects on domiciliary reinfestation by Triatoma infestans of smoothing the plaster of indoor walls prior to insecticide application (in Amamá village) relative to only insecticide application (in Trinidad-Mercedes villages) were evaluated in rural northwestern Argentina from 1992 to 1997. All domestic and peridomestic areas of each house were sprayed with 2.5% suspension concentrate deltamethrin at 25 mg/m(2) in October 1992, and infestations were assessed by various methods every 6 months. Domiciliary infestation decreased from 72-88% in 1992 to 6-17% in late 1995, to increase moderately thereafter without returning to baseline rates. Peridomestic sites were the first in becoming reinfested, and reached more abundant T. infestans populations than domiciliary areas. Domiciliary infestation rates and bug abundances were not significantly different between communities during surveillance. Domiciliary infestation rates in well-plastered houses were very low (5-9%) and approximately stable until 1996, but in houses with regular or bad plaster they consistently increased from 5 to 19-21% in both communities. Logistic multiple regression analysis showed that the likelihood of domestic infestation assessed through householders' collections was significantly and positively associated with the occurrence of an infested peridomestic site in the respective house, the occurrence of high-density domestic infestations before interventions, and well-plastered walls in 1996. Combining insecticide spraying and partial improvement of walls controlled domestic infestations and transmission of Trypanosoma cruzi effectively, but was not sufficient to eliminate T. infestans from the study area or increase the effectiveness of careful chemical control.
Collapse
Affiliation(s)
- M C Cecere
- Department of Ecology, Genetics and Evolution, Faculty of Exact and Natural Sciences, University of Buenos Aires, Ciudad Universitaria, C1428EHA, Buenos Aires, Argentina.
| | | | | | | | | |
Collapse
|
43
|
Abstract
American trypanosomiasis, or Chagas disease, caused by the protozoan parasite Trypanosoma cruzi and transmitted by blood-feeding triatomine bugs, is a chronic, frequently fatal infection that is common in Latin America. Neither adequate drugs nor a vaccine is available. A mathematical model calibrated to detailed household data from three villages in northwest Argentina shows that householders could greatly reduce the risk of human infection by excluding domestic animals, especially infected dogs, from bedrooms; removing potential refuges for bugs from walls and ceilings; and using domestically applied insecticides. Low-cost, locally practicable environmental management combined with intermittent use of insecticides can sustainably control transmission of T. cruzi to humans in rural Argentina and probably elsewhere.
Collapse
Affiliation(s)
- J E Cohen
- Laboratory of Populations, Rockefeller University and Columbia University, 1230 York Avenue, Box 20, New York, NY 10021, USA.
| | | |
Collapse
|
44
|
Lecuona RE, Edelstein JD, Berretta MF, La Rossa FR, Arcas JA. Evaluation of Beauveria bassiana (hyphomycetes) strains as potential agents for control of Triatoma infestans (Hemiptera: Reduviidae). JOURNAL OF MEDICAL ENTOMOLOGY 2001; 38:172-179. [PMID: 11296819 DOI: 10.1603/0022-2585-38.2.172] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Chagas disease constitutes a major human health problem in most Latin American countries. This endemic disease is transmitted by several species of triatomine bugs, the most important being Triatoma infestans (Klug). In this article, we report on the selection of strains of the entomopathogenic fungus Beauveria bassiana (Bals.) Vuill. virulent to T. infestans for possible use as bioinsecticides. Four strains of B. hassiana isolated from Argentina (Bb 1, 10, 25, and 65) were evaluated. To calculate mortality and mean lethal time, nymphs and adults of T. infestans were treated with conidia produced on complete agar medium and wheat brain and rice husk medium (WH). The LD50 for nymphs and adults of T. infestans was calculated. The effect of different temperatures (18, 22, 26, 30, and 34 degrees C) and relative humidities (35 and 90% RH) on mortality of nymphs were studied. We evaluated the compatibility of strains with Deltamethrin and Beta-Cypermethrin. Although the strain Bb 25 failed to grow on WH, the other three strains showed similar mortality values independent of the culture medium used to grow the microorganisms. The lowest LD50 values for nymphs were obtained with the strains Bb 10 and 65 and for adults were Bb 1, 10, and 65. The highest mean mortality was obtained with strain Bb 10, and among temperatures the highest mean mortality was observed at 26 degrees C. Relative humidity did not affect the mortality of T. infestans nymphs with all strains and temperatures assayed. Deltamethrin did not affect any of the three strains for the four studied doses, and Beta-Cypermethrin could be used in combination with the fungus only at low doses. The strain Bb 10 was selected for future assays under natural climatic conditions.
Collapse
Affiliation(s)
- R E Lecuona
- Instituto de Microbiología y Zoologí, IMYZA-INTA Castelar, Argentina.
| | | | | | | | | |
Collapse
|
45
|
Blanco SB, Segura EL, Cura EN, Chuit R, Tulián L, Flores I, Garbarino G, Villalonga JF, Gürtler RE. Congenital transmission of Trypanosoma cruzi: an operational outline for detecting and treating infected infants in north-western Argentina. Trop Med Int Health 2000; 5:293-301. [PMID: 10810029 DOI: 10.1046/j.1365-3156.2000.00548.x] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We designed a set of procedures for first-line local health services to detect and treat the congenital transmission of Trypanosoma cruzi at a province-wide scale, and field-tested the programme in the province of Tucumán, northwestern Argentina, from 1992 to 1994. The programme consists of routine screening of pregnant women for seroreactivity to T. cruzi, serological and parasitological follow-up of the newborn at least twice during the first year of age, treatment of the infected infants, and evaluation of the outcome. 927 (5.5%) of 16 842 pregnant women were seroreactive to T. cruzi by indirect haemagglutination assay and ELISA. Twenty-one (6.7%) of 315 newborns to seroreactive mothers were diagnosed as infected with T. cruzi parasites microhaematocrit concentration before 30 days of age. Five newborns who initially tested negative had a T. cruzi infection detected by microhaematocrit and/or serological techniques at 3 or 6 months of age. Thus, congenital infection was diagnosed in 26 (7.1%) infants born to seroreactive women and residing in houses free of triatomine bugs. Four of 6 infants born to seroreactive mothers died during the first year of age and had some evidence of T. cruzi infection; one of the deaths was attributed to T. cruzi based on clinical evidence. After specific treatment with nifurtimox or benznidazole, 30 of 32 infants remained parasitologically and serologically negative. This study shows the feasibility of controlling the incidence of congenitally acquired T. cruzi infections at a province-wide scale by means of a specific screening programme at first-line health services level.
Collapse
Affiliation(s)
- S B Blanco
- Servicio Nacional de Chagas, Córdoba, Argentina
| | | | | | | | | | | | | | | | | |
Collapse
|