Prevalence and multilocus genotyping of Giardia duodenalis in pigs of Shaanxi Province, northwestern China.

BACKGROUND: Giardiasis, caused by Giardia duodenalis (syn. Giardia intestinalis, Giardia lamblia), is a significant zoonotic parasitic disease of animals and humans worldwide. Accurate genotyping of G. duodenalis is essential for efficient control and management of giardiasis. The objectives of the present study were to investigate the prevalence and assemblages of giardiasis in pigs in Shaanxi Province, northwestern China, and for the first time study multilocus genotypes (MLGs) in pigs using multilocus genotyping technology in this region.

RESULTS: Of 560 faecal samples collected from five farms in Shaanxi Province, 45 were positive for G. duodenalis and significant differences in prevalence were observed among different locations. Differences in prevalence were also detected in pigs of different age groups, with the highest prevalence in sows and the lowest in boars. Two assemblages, A and E, were identified, and a mixed infection of both A and E was identified in one faecal sample. Assemblage E was predominant and widely distributed in all investigated areas and age groups. Genetic viability was detected for both assemblages, and four different multi-locus genotypes (MLGs) within assemblage E were found, MLGE1-MLGE4.

CONCLUSIONS: Giardia duodenalis was detected in pigs from Shaanxi Province, northwestern China, and genetic diversity was observed in these infections. Both assemblages A and E were detected, and four distinct MLGs within assemblage E were identified. These findings provide new data for controlling G. duodenalis infection in pigs.