Dispersal flight by Triatoma infestans in an arid area of Argentina

Vallvé, Silvana L.; Muscio, Oscar A.; Ghillini, M.; Alberti, Andrea C.; Wisnivesky‐Colli, Cristina

doi:10.1111/j.1365-2915.1988.tb00215.x

Cited by 71 publications

(24 citation statements)

References 7 publications

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“…Nothing is known concerning the flight capacity of T. vitticeps. T. infestans is capable of flying 200 m or more [119, 120] because it is capable of flying with wind assistance [121]. Another explanation for the high T. cruzi infection rates in T. vitticeps is that other non-sampled mammals, such as armadillos and bats, can be responsible for parasite maintenance [37, 87, 89, 122–124].…”

Section: Discussionmentioning

confidence: 99%

Ecological scenario and Trypanosoma cruzi DTU characterization of a fatal acute Chagas disease case transmitted orally (Espírito Santo state, Brazil)

et al. 2016

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BackgroundTrypanosoma cruzi infection via oral route results in outbreaks or cases of acute Chagas disease (ACD) in different Brazilian regions and poses a novel epidemiological scenario. In the Espírito Santo state (southeastern Brazil), a fatal case of a patient with ACD led us to investigate the enzootic scenario to avoid the development of new cases. At the studied locality, Triatoma vitticeps exhibited high T. cruzi infection rates and frequently invaded residences.MethodsSylvatic and domestic mammals in the Rio da Prata locality, where the ACD case occurred, and in four surrounding areas (Baia Nova, Buenos Aires, Santa Rita and Todos os Santos) were examined and underwent parasitological and serological tests. Triatomines were collected for a fecal material exam, culturing and mini-exon gene molecular characterization, followed by RFLP-PCR of H3/Alul. Paraffin-embedded cardiac tissue of a patient was washed with xylene to remove paraffin and DNA was extracted using the phenol-chloroform method. For genotype characterization, PCR was performed to amplify the 1f8, GPI and 18S rRNA genes. In the case of V7V8 SSU rRNA, the PCR products were molecularly cloned. PCR products were sequenced and compared to sequences in GenBank. Phylogenetic analysis using maximum likelihood method with 1000 bootstrap replicates was performed.ResultsNone of the animals showed positive hemocultures. Three rodents and two dogs showed signs of infection, as inferred from borderline serological titers. T. vitticeps was the only triatomine species identified and showed T. cruzi infection by DTUs TcI and TcIV. The analysis of cardiac tissue DNA showed mixed infection by T. cruzi (DTUs I, II, III and IV) and Trypanosoma dionisii.ConclusionsEach case or outbreak of ACD should be analyzed as a particular epidemiological occurrence. The results indicated that mixed infections in humans may play a role in pathogenicity and may be more common than is currently recognized. Direct molecular characterization from biological samples is essential because this procedure avoids parasite selection. T. dionisii may under certain and unknown circumstances infect humans. The distribution of T. cruzi DTUS TcIII and TcIV in Brazilian biomes is broader than has been assumed to date.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1754-4) contains supplementary material, which is available to authorized users.

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Section: Discussionmentioning

confidence: 99%

Ecological scenario and Trypanosoma cruzi DTU characterization of a fatal acute Chagas disease case transmitted orally (Espírito Santo state, Brazil)

et al. 2016

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“…Although dispersal studies on vectors have been conducted since the eighties ( e.g. , [29]), accurate descriptions of the spatio-temporal distribution of most tropical pathogen vectors are still lacking. Along with recent advances in spatially explicit models [48], our study proposes a contribution to better characterize the dispersal behavior of the vectors of T. cruzi , responsible for Chagas disease.…”

Section: Discussionmentioning

confidence: 99%

“…This allowed us to apply a matrix of landscape resistance to our grid. Based on previous studies on T. infestans by [29], the maximal active dispersal distance was set to 2 km per generation over the entire landscape. To simulated passive dispersal, the dispersal distance on roads was fixed to a maximum of 10 km per generation (corresponding to d = 5, with d varying from 1 to 5 grid cells in our simulations).…”

Section: Methodsmentioning

confidence: 99%

Simulating Population Genetics of Pathogen Vectors in Changing Landscapes: Guidelines and Application with Triatoma brasiliensis

et al. 2014

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BackgroundUnderstanding the mechanisms that influence the population dynamics and spatial genetic structure of the vectors of pathogens infecting humans is a central issue in tropical epidemiology. In view of the rapid changes in the features of landscape pathogen vectors live in, this issue requires new methods that consider both natural and human systems and their interactions. In this context, individual-based model (IBM) simulations represent powerful yet poorly developed approaches to explore the response of pathogen vectors in heterogeneous social-ecological systems, especially when field experiments cannot be performed.Methodology/Principal FindingsWe first present guidelines for the use of a spatially explicit IBM, to simulate population genetics of pathogen vectors in changing landscapes. We then applied our model with Triatoma brasiliensis, originally restricted to sylvatic habitats and now found in peridomestic and domestic habitats, posing as the most important Trypanosoma cruzi vector in Northeastern Brazil. We focused on the effects of vector migration rate, maximum dispersal distance and attraction by domestic habitat on T. brasiliensis population dynamics and spatial genetic structure. Optimized for T. brasiliensis using field data pairwise fixation index (FST) from microsatellite loci, our simulations confirmed the importance of these three variables to understand vector genetic structure at the landscape level. We then ran prospective scenarios accounting for land-use change (deforestation and urbanization), which revealed that human-induced land-use change favored higher genetic diversity among sampling points.Conclusions/SignificanceOur work shows that mechanistic models may be useful tools to link observed patterns with processes involved in the population genetics of tropical pathogen vectors in heterogeneous social-ecological landscapes. Our hope is that our study may provide a testable and applicable modeling framework to a broad community of epidemiologists for formulating scenarios of landscape change consequences on vector dynamics, with potential implications for their surveillance and control.

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“…In northwestern Argentina and Bolivia, peridomestic foci of T. infestans detected just 1–3 months after applying pyrethroids were most probably residual foci ( 5 , 8 – 10 ). In the apparent absence of sylvatic foci of T. infestans in northern Argentina ( 11 ), the appearance of adult T. infestans can be explained by active dispersal from foci located in its flight distance ( 12 – 14 ). This flight distance is well within the range of clustering detected around external (up to 1,500 m) and internal sources (up to 400 m) observed in an earlier study ( 7 ).…”

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confidence: 99%