Parasites (Blastocystis hominis, Dientamoeba fragilis, Cryptosporidium spp., Cyclospora cayetanensis, Entamoeba histolytica, Giardia lamblia) laboratory diagnostic in Latvia 2019-2021

Description

Background
In humans, infection with an intestinal parasite can be asymptomatic, but some
cases present with diarrhea and other signs of gastroenteritis. Molecular approaches
are becoming increasingly available for detecting intestinal parasites, molecular
methods demonstrate excellent sensitivity and specificity with respect to
conventional methods such as microscopy.
Methods
In 2019 – 2021 891 samples were tested in NRL of Latvia to detect parasites DNA
by Allplex GI-Parasites Assay, Seegene from stool samples.
We compared B.hominis, D.fragilis, Cryptosporidium spp., C. cayetanensis, E.
histolytica, G. lamblia DNA positive samples with microscopy.
Results
We obtained 308/891 (34.6%) positive parasites DNA. 141/308 (45.8%) B.hominis
DNA was found; D.fragilis DNA - 91/308 (29.5%); Cryptosporidium spp DNA - 9/308
(2.9%); G.lamblia DNA - 2/308 (0.7%); C. cayetanensis DNA - 1/308 (0.3%);
E.histolytica DNA - 0/308; B.hominis + D.fragilis DNA - 57/308 (18.5%); B.hominis +
Cryptosporidium spp. DNA - 3/308 (1%); Cryptosporidium spp. + D.fragilis DNA -
2/308 (0.7%); B.hominis + G.lamblia DNA - 1/308 (0.3%); D.fragilis + G.lamblia DNA
-1/308 (0.3%).
The analysis of data showed that 60/308 (19.5%) positive parasites DNA samples
were tested by microscopy: B.hominis – 30/141 (16/30 positive microscopy, 14/30
negative microscopy); D.fragilis – 20/91 (19/91 negative microscopy and 1/91
B.hominis positive microscopy but D.fragilis negative; Cryptosporidium spp. – 2/9
(negative microscopy); G.lamblia - 1/2 (negative microscopy); B.hominis + D.fragilis
– 6/57 (4/57 B.hominis positive microscopy, D.fragilis – negative; 2/57 negative
microscopy); B.hominis + Cryptosporidium spp. – 1/3 (B.hominis positive microscopy
but Cryptosporidium spp. negative).
Further investigation of parasites DNA samples showed that 583/891 (65.4%) were
negative by Multiplex PCR. 113/583 (19.4%) were tested by both methods: 108/583
(18.5%) were negative and 5/583 (0.9%) were positive by microscopy (4/5 -
B.hominis, 1/5 - E.histolytica) but negative by PCR.
Conclusions
Developments of Multiplex PCR-based assays have the potential to overcome
gastrointestinal tract parasite infections detection. From 308 positive parasite DNA
results mostly are found B.hominis and D.fragilis. 19.5% samples were tested by
PCR and microscopy: only 5.2% samples were positive by both methods, all
B.hominis, 1.6% - partially coincided and 12.6% were negative by microscopy,
however only 0,9% samples were negative by PCR but positive by microscopy.

Period	22 Apr 2022 → 26 Apr 2022
Event title	32nd European Congress of Clinical Microbiology and Infectious Diseases (ECCMID)
Event type	Congress
Conference number	32
Organiser	European Society of Clinical Microbiology and Infectious Diseases
Location	Lisbon, PortugalShow on map
Degree of Recognition	International