TriatoDex, an electronic identification key to the Triatominae (Hemiptera: Reduviidae), vectors of Chagas disease: Development, description, and performance

PLoS One. 2021 Apr 22;16(4):e0248628. doi: 10.1371/journal.pone.0248628. eCollection 2021.

Abstract

Correct identification of triatomine bugs is crucial for Chagas disease surveillance, yet available taxonomic keys are outdated, incomplete, or both. Here we present TriatoDex, an Android app-based pictorial, annotated, polytomous key to the Triatominae. TriatoDex was developed using Android Studio and tested by 27 Brazilian users. Each user received a box with pinned, number-labeled, adult triatomines (33 species in total) and was asked to identify each bug to the species level. We used generalized linear mixed models (with user- and species-ID random effects) and information-theoretic model evaluation/averaging to investigate TriatoDex performance. TriatoDex encompasses 79 questions and 554 images of the 150 triatomine-bug species described worldwide up to 2017. TriatoDex-based identification was correct in 78.9% of 824 tasks. TriatoDex performed better in the hands of trained taxonomists (93.3% vs. 72.7% correct identifications; model-averaged, adjusted odds ratio 5.96, 95% confidence interval [CI] 3.09-11.48). In contrast, user age, gender, primary job (including academic research/teaching or disease surveillance), workplace (including universities, a reference laboratory for triatomine-bug taxonomy, or disease-surveillance units), and basic training (from high school to biology) all had negligible effects on TriatoDex performance. Our analyses also suggest that, as TriatoDex results accrue to cover more taxa, they may help pinpoint triatomine-bug species that are consistently harder (than average) to identify. In a pilot comparison with a standard, printed key (370 tasks by seven users), TriatoDex performed similarly (84.5% correct assignments, CI 68.9-94.0%), but identification was 32.8% (CI 24.7-40.1%) faster on average-for a mean absolute saving of ~2.3 minutes per bug-identification task. TriatoDex holds much promise as a handy, flexible, and reliable tool for triatomine-bug identification; an updated iOS/Android version is under development. We expect that, with continuous refinement derived from evolving knowledge and user feedback, TriatoDex will substantially help strengthen both entomological surveillance and research on Chagas disease vectors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Animals
  • Brazil / epidemiology
  • Chagas Disease / epidemiology*
  • Chagas Disease / transmission
  • Female
  • Humans
  • Insect Vectors* / anatomy & histology
  • Insect Vectors* / classification
  • Male
  • Middle Aged
  • Mobile Applications*
  • Triatominae* / anatomy & histology
  • Triatominae* / classification
  • Young Adult

Grants and funding

DAR received specific funding of Coordenação de Aperfeiçoamento de Pessoal de Nível Superior https://www.capes.gov.br/ Award Number: finance code 001. RGG received specific funding of Conselho Nacional de Desenvolvimento Científico e Tecnológico http://www.cnpq.br/ Award Number: 426619/2018-8. JASB received salary from H2J Comunicação & Marketing, Brasília, Brazil and MRA received salary from Real Comércio e Indústria de Alumínio Ltd. The specific roles of these authors are articulated in the ‘author contributions’ section. The funders did not have any role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.