Improvement of routine diagnosis of intestinal parasites with multiple sampling and SAF-fixative in the triple-faeces-test.

BACKGROUND AND STUDY AIM

To perform optimal laboratory diagnosis of intestinal parasites is demanding. Because intestinal parasites are intermittently shedded, examination of multiple stools is imperative. For reliable detection of vegetative stages of protozoa, fresh stools should be examined direct after production, or stools should be preserved in a fixative. These aspects in routine practice are often neglected with as a result lower sensitivity of the diagnostic procedure. With application of the Triple-Faeces-Test (TFT) protocol, where both multiple sampling and a SAF-fixative are included, these practical problems could be overcome. The aim of this study was to compare the recovery of intestinal parasites in faecal specimens using TFT protocol versus the conventional diagnostic method (ether-sedimentation of one fresh stool sample).

METHODS

During a three years period, results obtained in routine practice with the TFT protocol were compared with results from examination of sediment obtained with the ethyl-acetate-sedimentation technique of one unpreserved faeces specimen.

RESULTS

From 2776 patients, 28.1% were positive for one or more intestinal parasites after examination of the TFT test, compared to 10.3% positivity with the conventional method (P < 0.05). Pathogenic species and non pathogenic species were observed respectively 191 and 449 times with TFT and 105 and 152 times with conventional method (P < 0.05).

CONCLUSIONS

The application of the Triple-Faeces-Test in routine clinical practice significantly increased recovery of intestinal parasitic infections.