Table 2.

Principle, advantages and limitations of commonly used faecal egg counting techniques

Method	Principle	Advantages	Limitations
Direct smear	The small amount of fresh faeces mixed with saline (or iodine) on a microscope slide	Cheap, fast processing time	Qualitative, very low accuracy, precision and sensitivity
Cornell-Wisconsin	Based on centrifugal flotation of eggs in a salt solution in a tube, collection onto a coverslip and counting under a microscope	Cheap, high limit of detection	Time-consuming, low accuracy and very low precision
McMaster	Faeces mixed in a flotation solution are loaded onto chambers of a slide and the floated eggs are counted	Cheap, medium processing time	Low sensitivity
FLOTAC®	Based on centrifugal-flotation of eggs in a specialised apparatus and subsequent translation of the top layer	Cheap, high sensitivity, very high accuracy and precision	Time-consuming, special equipment (centrifugation rotors) required
Mini-FLOTAC®	A modified version of FLOTAC without centrifugation step and reduced reading volume	High sensitivity, accuracy and precision, medium processing time	Detection of some parasites (e.g. trematodes) requires centrifugation
FECPAK®	Eggs are floated in a flotation solution, accumulated into a single viewing area and imaged	Does not require technical skills as eggs identified and counted remotely, digitalised images	Low accuracy, precision and medium sensitivity, time-consuming
Parasight System®	A faecal sample mixed in water is filtered to remove debris, eggs are labelled with a fluorescent dye, imaged and counted using an automated algorithm	High precision, does not require technical skills, fast, automated counting, digitalised images	Expensive, some results need to be confirmed visually, does not detect overlying eggs, cannot differentiate with high debris background

Note: Sources: Cringoli et al. (2017); Sukas et al. (2019).