Background
Parasitic infections, particularly those caused by protozoa, represent a considerable public health problem in developing countries.
Blastocystis
,
Giardia duodenalis
,
Cryptosporidium
spp. and the
Entamoeba
complex (
Entamoeba histolytica, Entamoeba dispar
and
Entamoeba moshkovskii)
are the most common etiological causes of intestinal parasitic infections.
Methods
We carried out a descriptive cross-sectional study in school-age children attending a daycare institution in commune eight of Popayán, Cauca (Southwest Colombia). A total of 266 fecal samples were collected (258 from children and eight from pets).
Blastocystis
,
G. duodenalis
,
Cryptosporidium
spp. and the
Entamoeba
complex were identified by microscopy, quantitative real-time PCR (qPCR) and conventional PCR. The concordance of qPCR and microscopy was assessed using the Kappa index. Molecular characterization was conducted to identify
Blastocystis
subtypes (18S),
G. duodenalis
assemblages (
tpi
and
gdh
) and
Cryptosporidium
species/subtypes (18S and GP60). Potential associations between intestinal parasitism and sociodemographic factors were examined using bivariate analyses.
Results
A total of 258 fecal samples from children were analyzed by microscopy and 255 samples were analyzed by qPCR. The prevalence of
Blastocystis
was between 25.19% (microscopy) and 39.22% (qPCR), that of
G. duodenalis
was between 8.14% (microscopy) and 10.59% (qPCR), that of
Cryptosporidium
spp. was estimated at 9.8% (qPCR), and that of the
Entamoeba
complex was between 0.39% (conventional PCR) and 0.78% (microscopy). The concordance between microscopy and qPCR was very low.
Blastocystis
ST1 (alleles 4, 8, and 80), ST2 (alleles 11, 12, and 15), ST3 (alleles 31, 34, 36, 38,57, and 151), and ST4 (alleles 42 and 91),
G. duodenalis
assemblages AII, BIII, BIV and D,
C. parvum
subtype IIa and
C. hominis
subtype IbA9G3R2 were identified. The only identified member of the
Entamoeba
complex corresponded to
E. histolytica
. No statistically significant association was identified between parasitic infection and any sociodemographic variable.
Conclusion
This study revealed the usefulness of molecular methods to depict the transmission dynamics of parasitic protozoa in southwest Colombia. The presence of some of t...