Comparison of the Performance of Faecal Concentration Techniques and Mini Parasep® SF Faecal Parasite Concentrator on Faecal Parasite Diagnosis

Abstract

Parasitic infection is still a public health problem in Thailand. Ministry of Public Health has been implementing policy to minimize the rate of infection by promoting individual knowledge, measurement and control, treatment and prevention of the infection.  Unfortunately, various types of parasites sporadically spread in many regions of Thailand. The purpose of this study was to evaluate the diagnostic performance of 3 faecal examination techniques including the formalin-ether concentration technique (FECT), the formalin-ethyl acetate concentration technique (FACT) and the Mini Parasep® SF faecal parasite concentrator (Mini Parasep® SF). The comparative examinations were performed in 360 faecal samples collected from patients in the Hospital for Tropical Diseases during October 2019 to September 2021. The results showed that FECT and FACT gave the highest capacity for parasitic detection, at 28.33% of total analyzed samples, while 25.83% were detected by the Mini Parasep® SF. The most common types of helminth eggs and larva detected by these techniques were Opisthorchis viverrini and the most common protozoa was Giardia lamblia. The sensitivity of FECT, FACT and Mini Parasep® SF for parasitic detection​​ were 99.03, 99.03 and 90.29%, respectively. The negative predictive values ​​ of FECT, FACT and Mini Parasep® SF were 99.61, 99.61 and 96.25%, respectively. These results indicated that FECT and FACT possessed a higher sensitivity and negative predictive values ​​than Mini Parasep® SF. However, chi-square statistics analysis showed statistical indifference among the three techniques (p>0.05 and high kappa coefficient). These indicated that analysis results shared consistency at a high level. In conclusion, FECT, FACT and Mini Parasep® SF can be used interchangeably and the selection of techniques for detection of parasites should be based on capability of individual laboratory.