PeerJ (May 2022)

Automatic detection of the parasite Trypanosoma cruzi in blood smears using a machine learning approach applied to mobile phone images

  • Mauro César Cafundó Morais,
  • Diogo Silva,
  • Matheus Marques Milagre,
  • Maykon Tavares de Oliveira,
  • Thaís Pereira,
  • João Santana Silva,
  • Luciano da F. Costa,
  • Paola Minoprio,
  • Roberto Marcondes Cesar Junior,
  • Ricardo Gazzinelli,
  • Marta de Lana,
  • Helder I. Nakaya

DOI
https://doi.org/10.7717/peerj.13470
Journal volume & issue
Vol. 10
p. e13470

Abstract

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Chagas disease is a life-threatening illness caused by the parasite Trypanosoma cruzi. The diagnosis of the acute form of the disease is performed by trained microscopists who detect parasites in blood smear samples. Since this method requires a dedicated high-resolution camera system attached to the microscope, the diagnostic method is more expensive and often prohibitive for low-income settings. Here, we present a machine learning approach based on a random forest (RF) algorithm for the detection and counting of T. cruzi trypomastigotes in mobile phone images. We analyzed micrographs of blood smear samples that were acquired using a mobile device camera capable of capturing images in a resolution of 12 megapixels. We extracted a set of features that describe morphometric parameters (geometry and curvature), as well as color, and texture measurements of 1,314 parasites. The features were divided into train and test sets (4:1) and classified using the RF algorithm. The values of precision, sensitivity, and area under the receiver operating characteristic (ROC) curve of the proposed method were 87.6%, 90.5%, and 0.942, respectively. Automating image analysis acquired with a mobile device is a viable alternative for reducing costs and gaining efficiency in the use of the optical microscope.

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