Detection of intestinal parasites in human faecal samples using dissolved air flotation

Area of Science:

• Medical laboratory diagnostics
• Parasitology
• Public health

Background:

• Ova and parasite (O&P) examination is crucial for diagnosing parasitic infections but needs technological enhancement.
• Dissolved air flotation (DAF) is an effective method for separating suspended solids.

Purpose of the Study:

• To develop and validate a novel DAF-based procedure for detecting intestinal parasites.
• To improve the diagnostic accuracy of O&P examinations.

Main Methods:

• Collected 500 volunteer samples, initially screened by direct examination.
• Utilized the Three Faecal Test (TF-Test) for triplicate DAF tests.
• Optimized DAF parameters and validated the protocol against gold standards.

Main Results:

• Achieved 80% parasite recovery with a 10% saturated volume proportion and cationic surfactant.
• DAF protocol demonstrated high diagnostic performance: 91% sensitivity, 100% specificity, 93% accuracy, and substantial kappa agreement (k=0.64).
• Modifications to the needle device did not significantly impact parasite recovery.

Conclusions:

• The DAF principle is suitable for routine laboratory processing of fecal samples.
• This DAF-based method enables reliable intestinal parasite detection.
• The developed procedure offers a significant advancement in O&P examination.