The Kubic FLOTAC microscope (KFM): a new compact digital microscope for helminth egg counts

Abstract

The Kubic FLOTAC microscope (KFM) is a compact, low-cost, versatile and portable digital microscope designed to analyse fecal specimens prepared with Mini-FLOTAC or FLOTAC, in both field and laboratory settings. In this paper, we present the characteristics of the KFM along with its first validation for fecal egg count (FEC) of gastrointestinal nematodes (GINs) in cattle. For this latter purpose, a study was performed on 30 fecal samples from cattle experimentally infected by GINs to compare the performance of Mini-FLOTAC either using a traditional optical microscope (OM) or the KFM. The results of the comparison showed a substantial agreement (concordance correlation coefficient = 0.999), with a very low discrepancy (−0.425 ± 7.370) between the two microscopes. Moreover, the KFM captured images comparable with the view provided by the traditional OM. Therefore, the combination of sensitive, accurate, precise and standardized FEC techniques, as the Mini-FLOTAC, with a reliable automated system, will permit the real-time observation and quantification of parasitic structures, thanks also to artificial intelligence software, that is under development. For these reasons, the KFM is a promising tool for an accurate and efficient FEC to improve parasite diagnosis and to assist new generations of operators in veterinary and public health.

Keywords: Digital microscope; Kubic FLOTAC microscope; Mini-FLOTAC; Tele-Parasitology; fecal egg count.

Graphical abstract

Fig. 1.

KFM used with the Mini-FLOTAC (A) and FLOTAC devices (B).

Fig. 2.

(A) FreeCAD and Design Spark Mechanical of the KFM (external view); (B) FreeCAD and Design Spark Mechanical of the KFM (internal view); (C) schematic diagram showing mechanical, electronic and optical systems of the KFM and (D) a particular of the handling motor based on the no-standard Cartesian system.

Fig. 3.

Digital imaging of GIN eggs (green arrow) and air bubbles (red square) using the KFM with a digital zoom 100× (A), 200× (B) and 300× (C).

Fig. 4.

Image of a part of a Mini-FLOTAC chamber, captured by technological devices (smartphone, tablet or a PC) connected with the microscope that shows GIN eggs (green arrows) and air bubbles (red squares).

Fig. 5.

Comparison of the mean of counted eggs between the readings by the OM and the KFM for each sample.

Fig. 6.

Correlation between the number of counted eggs based on the examination of Mini-FLOTAC using the OM and KFM for each level of egg counts and total counts.

Fig. 7.

Bland–Altman plot of number of counted GIN eggs based on the examination of Mini-FLOTAC using OM and KFM.