Prevalence and Molecular Characterisation of Cryptosporidium spp. and Giardia duodenalis in Equines in Algeria.

BACKGROUND

Limited data are available on the epidemiology of Cryptosporidium spp. and Giardia duodenalis in equines in Algeria. No prior molecular data existed on giardiasis in this host population.

OBJECTIVES

This cross-sectional study aimed to determine the prevalence and molecular diversity of Cryptosporidium spp. and G. duodenalis in equines across multiple regions of Algeria, and to characterise species, subtypes and assemblages present.

METHODS

Between December 2021 and December 2022, 197 faecal samples were collected from 104 horses, 89 donkeys, 2 ponies, 1 zebra and 1 mule from 46 private farms, 2 equestrian centres and 1 zoological park in eastern and central Algeria. Detection used microscopy and PCR. Cryptosporidium species and subtypes were identified by sequence analysis of SSU rRNA and gp60 genes. G. duodenalis was screened by probe-based qPCR with genotyping attempted at the tpi and bg loci.

RESULTS

The overall molecular prevalence of Cryptosporidium was 34% (horses 31%, donkeys 38%), and G. duodenalis was 4.6% (horses 2.9%, donkeys 7%). Male equines had a significantly higher Cryptosporidium infection rate than females; no other epidemiological variable was significant for either parasite. Ten Cryptosporidium isolates were genotyped as four species: C. parvum (subtype IIaA20G1R1), C. equi (VIaA15G3, VIaA11G2), C. hominis (IkA15G1) and C. muris. C. equi and C. hominis were reported for the first time in Algerian horses and donkeys, respectively. Genotyping of G. duodenalis-positive samples was unsuccessful due to sequencing failure, likely attributable to low parasite DNA concentrations.

CONCLUSIONS

This study reports the first molecular prevalence data for G. duodenalis and the first detection of C. equi and C. hominis in Algerian equines. The zoonotic C. parvum subtype IIaA20G1R1, previously detected in Algerian HIV patients, highlights equines as a potential reservoir. Expanded One Health surveillance with longitudinal and seasonal sampling is recommended.