Detection of Parasites in Stool Samples by PCR
Diarrheal diseases are extremely common in the developed and developing worlds and are major causes of morbidity and mortality, affecting millions of individuals each year. The aetiologies of diarrhea include viruses, bacteria and parasites. Of parasites, Entamoeba histolytica, Giardia lamblia and Cryptosporidium sp. are considered to be the most common.
Our data at LifeLabs in Ontario show an overall prevalence of Intestinal parasitic pathogens (IPP) ranging from 4.6 to 5.8%. Protozoa accounted for 85% of IPPs while helminths for 15%. Distribution of protozoa were: Dientamoeba fragilis 59.6%, Giardia lamblia 24.7%, Entamoeba histolytica/dispar 11.4%, Cryptosporidium sp. 2.3%, Cyclospora sp. 2.0%.
Seasonality was observed with Cyclospora sp and Cryptosporidium sp., peaking in mid-summer (May-July) and late summer (July to September), respectively.
Among helminths, pinworm represented 67%, Ascaris lumbricoides 7.4%, Trichuris trichura 5.6%, hookworm 4.5%, Strogyloides stercoralis 4.4%, Taenia sp.2.3%, Hymenolepis nana 2.9%, Diphyllobothrium sp. 2.4%, Schistosoma mansoni 1.9%, Clonorchis sinensis 1.1%, Trichostrongylous sp. 0.5%, and Fasciola/Fasciolopsis 0.2%.
PCR testing will replace the current traditional microscopic method of testing. This new technology offers high sensitivity for protozoa pathogen detection and a faster turnaround time for reporting of our results. It detects six most common protozoa parasites: Giardia lamblia, Entamoeba histolytica, Cryptosporidium spp., Blastocystis hominis, Dientamoeba fragilis and Cyclospora cayetanensis.