Intestinal giardiasis in children: Five years' experience in a reference unit

Prevalence and temporal dynamics of Cryptosporidium spp., Giardia duodenalis, and Blastocystis sp. among toddlers attending day-care centres in Spain. A prospective molecular-based longitudinal study

Giardia duodenalis, Cryptosporidium spp., and Blastocystis sp. are common intestinal eukaryotic parasites affecting children in developed and resource-limited countries. Lack of information on the epidemiology and long-term stability in asymptomatic children complicates interpretation of transmission and pathogenesis. To assess the occurrence, genetic diversity, and temporal dynamics of intestinal eukaryotic parasites in young children, 679 stool samples from 125 toddlers attending six public day-care centres in Central Spain were collected bimonthly within a 1-year period. Detection and identification of species/genotypes were based on PCR and Sanger sequencing methods. Four eukaryotic species were identified: G. duodenalis (2.5‒31.6%), Cryptosporidium spp. (0.0‒2.4%), Blastocystis sp. (2.5‒6.4%), and Entamoeba dispar (0.0‒0.9%). Entamoeba histolytica and Enterocytozoon bieneusi were undetected. Sequence analyses identified assemblage A (63.6%) and B (36.4%) within G. duodenalis (n = 11), C. hominis (40%), C. parvum (40%), and C. wrairi (20%) within Cryptosporidium spp. (n = 5), and ST1 (3.8%), ST2 (46.2%), ST3 (15.4%), and ST4 (34.6%) within Blastocystis sp. (n = 26). Giardia duodenalis sub-assemblage AII/AIII was detected in a toddler for 10 consecutive months. Stable carriage of Blastocystis ST2 allele 9, ST3 allele 34, and ST4 allele 42 was demonstrated in five toddlers for up to 1 year.   Conclusions: Giardia duodenalis and Blastocystis sp. were common in toddlers attending day-care centres in Central Spain. Long-term infection/colonization periods by the same genetic variant were observed for G. duodenalis (up to 10 months) and Blastocystis sp. (up to 12 months). What is Known: • Asymptomatic carriage of G. duodenalis and Blastocystis sp. is frequent in toddlers. • The epidemiology and long-term stability of these eukaryotes in asymptomatic young children is poorly understood. What is New: • Long-term colonization/infection periods by the same genetic variant were described for Blastocystis sp. (up to 12 months) and G. duodenalis (up to 10 months).

Screening for parasites in migrant children

BACKGROUND

Globalization has pushed population movements in the last decades, turning imported diseases into the focus. Due to behavioral habits, children are at higher risk of acquiring iparasitosis. This study aims to investigate the prevalence of parasites in migrant children and factors associated with parasitic diseases.

METHOD

Retrospective cross-sectional study (2014-2018) including children diagnosed with parasitosis. The diagnosis was based on serology and/or microscopic stool-sample evaluation. Epidemiological and clinical data were recorded.

RESULTS

Out of 813 migrant children screened, 241 (29.6%) presented at least one parasite, and 89 (10.9%) more than one. The median age was 6.6 years (IQR: 3.1-11.9) and 58.9% were males. Most cases were referred for a health exam; only 52.3% of children were symptomatic, but 43.6% had eosinophilia. The most common diagnosis were giardiasis (35.3%), schistosomiasis (19.1%), toxocariasis (15.4%), and strongyloidiasis (9.1%). After the multivariate analysis, African origin and presenting with eosinophilia were the main risk factors for parasitism.

CONCLUSIONS

parasitosis are frequent among migrant children. Children are often asymptomatic, and thus active screening for parasitosis should be considered among high-risk populations. Eosinophilia can be useful to guide complimentary tests, as well as geographical origin, but normal eosinophil count does not exclude parasitosis.