BACKGROUND: Because of a lack of quality control (QC) materials, stool examination has not been standardised. This study examined intestinal parasites in diarrhea specimens to manufacture and evaluate the performance stability of QC materials for stool examination. METHODS: This study examined diarrhea specimens submitted for stool culture. Microscopic examination was performed using the direct smear and formalin-ether concentration method (Military General Laboratory, MGL). Enzyme-linked immunosorbent assay (ELISA) kits (R-Biopharm AG, Germany) and xTAG Gastrointestinal Pathogen Panel (Luminex Corp., USA) were used for the three major protozoa: Cryptosporidium parvum, Giardia lamblia, and Entamoeba histolytica. Polymerase chain reaction (PCR) was performed for Dientamoeba fragilis and Blastocystis hominis. The QC materials for stool examination were generated using Diphyllobothrium nihonkaiense ova. The manufactured QC materials were evaluated under different storage conditions, with varying preservatives, temperatures, and storage times. RESULTS: From November 2015 to April 2016, 82 diarrhea specimens were collected and tested. All results from microscopy and ELISA were negative; C. parvum (n=2) and G. lamblia (n=1) were detected by xTAG, while D. fragilis (n=10) and B. hominis (n=2) were detected by PCR. High- and low-concentration QC materials were manufactured. Using the high-concentration QC material, ova were observed in all storage conditions using MGL. Using the low-concentration QC material, the ova were observed until 14 days, but not after 3 weeks. CONCLUSIONS: It should be considered for making QC materials for stool examinations that focus on D. fragilis and B. hominis frequently found in Korea and with the caution to the low-concentration of QC materials could be unstable.
Blastocystis hominis ; Cryptosporidium parvum ; Diarrhea* ; Dientamoeba ; Diphyllobothrium ; Entamoeba histolytica ; Enzyme-Linked Immunosorbent Assay ; Giardia ; Giardia lamblia ; Korea ; Methods* ; Microscopy ; Ovum ; Parasites* ; Polymerase Chain Reaction ; Quality Control*

A survey of intestinal parasites infection among Korean people has been carried out during July 1969 to December 1970. A total of 2,250 stool specimens (male 1,101, female 1,146) was collected from all the provinces and Seoul city in Korea. The specimens were examined routinely by direct fecal smear, zinc sulfate flotation and formalin-ether sedimentation techniques. The results are summarized as follows: Of 2,250 specimens examined, l,803(80.l per cent) were positive for intestinal parasites. The positive rates of intestinal helminths were 1,644(73.1 per cent) among 2,250; Ascaris lumbricoides 46.0 per cent, Trichocephalus trichiurus 46.8 percent, hookworm 6.8 per cent, Trichostrongylus orientalis 7.0 percent, Clonorchis sinensis 12.1 percent, Enterobius vermicularis 1.6 per cent, Hymenolepis nana 0.7 percent, Taenia species 0.3 per cent, Metagonimus yokogawai 0.04 percent, Fasciolidae 0.04 per cent and one case of lung fluke Paragonimu westermani. The positive rstes of intestinal protozoa were 786(34.9 per cent); Entamoeba histolytica 6.4 per cent, Entamoeba coli 20.5 percent, Endolimax nana 10.0 per cent, Giardia lamblia 5.1 per cent, Trichomonas hominis 1.1 percent, Chilomastix mesnili 0.5 percent, Iodamoeba butschlii 0.6 percent, Enteromonas hominis 0.7 percent, Dientamoeba fragilis 0.1 per cent and one case of Isospora hominis. Sexual distribution of helminths and protozoan infections showed higher rate in female than that of male, except C. sinensis, H. nana, Taenia species or G. lamblia Infections of T. trichiurus, hookworm, T. orientalis, C. sinensis, Taenia species, E. histolytica, E. coli and E. nana increased with age. Conversely, H. nana and G. lamblia infections were more predominent in younger ages.
parasitology-helminth-protozoa-trematoda-nematoda-cestoda ; Ascaris lumbricoides ; Trichocephalus trichiurus-Trichuris trichiura ; hookworm ; Trichostrongylus orientalis ; Clonorchis sinensis ; Enterobius vermicularis ; Hymenolepis nana ; Taenia species ; lamblia ; Trichomonas hominis ; Chilomastix mesnili ; Iodamoeba butschlii ; Enteromonas hominis ; Dientamoeba fragilis ; Isospora hominis ; epidemiology ; stool examination