Prevalence, Risk Factors and Multilocus Genotyping of Giardia intestinalis in Dairy Cattle, Northwest China

Abstract

Giardia intestinalis is a cosmopolitan protozoan parasite that can infect a range of animals, including dairy cattle. As information regarding the prevalence and genotyping of G. intestinalis infection in dairy cattle in northwestern China is limited, 2,945 feces samples from 1,224 dairy cattle in Gansu Province and from 1,614 in Ningxia Hui Autonomous Region (NXHAR) were examined between December 2012 and March 2014. The overall prevalence of G. intestinalis was 3.63% (107/2,945), with 2.63% and 4.38% in Gansu and NXHAR, respectively. Logistic regression analysis showed region, age and season to be significant risk factors for G. intestinalis infection. Assemblage analysis identified 106 assemblage E and one assemblage A at the triose phosphate isomerase (tpi) locus in this study. Intravariations were also detected at tpi, glutamate dehydrogenase (gdh) and beta giardin (bg) loci within assemblage E, showing seven, three, and five new subtypes, respectively. Moreover, 13 new multilocus genotypes (E20-E32) were observed in assemblage E. Effective strategies and measures should be taken to prevent and control giardiasis in Gansu and NXHAR.

Occurrence and multilocus genotyping of Giardia intestinalis assemblage C and D in farmed raccoon dogs, Nyctereutes procyonoides, in China

“…These findings can provide baseline data for further studies of the analyzation of G. duodenalis assemblage MLGs. These results also indicate high genetic diversity of G. intestinalis assemblage C in raccoon dogs in China, which agree with previous reports showing that the same G. intestinalis assemblage isolates may be divided into different MLGs [3, 21]. …”

“…Therefore, higher raccoon dog density in Liaoning Province is one of the most important reasons why raccoon dogs from Liaoning have a higher G. intestinalis prevalence than those from other provinces ( P  = 0.0198) (Table 2). A previous study suggested that higher precipitation can create more opportunities for G. intestinalis transmission [3]. This is supported by the higher G. intestinalis prevalence detected in summer and spring in the present study (Table 2).…”

“…In the present study, the overall prevalence of G. intestinalis in farmed raccoon dogs was 7.21 % (22/305, 95 % CI: 4.31–10.12), a value much higher than that found in foxes in Croatia (4.5 %) [16] and Norway (4.8 %) [17]. The prevalence is also higher than that reported in a range of other animals in northern China, such as 3.63 % in dairy cattle in northwest China [3], 6.0 % in yaks in the central western region of China [18], 0.6 % in non-human primates in Henan Province [19], 5.0 % in sheep and goats in Heilongjiang Province [20], but slightly lower than that in golden takins (8.9 %) in Shannxi Province [21], police and farm dogs (13.2 %) in Shenyang, Liaoning Province [22] and rabbits (7.41 %) in Heilongjiang Province [23]. The difference may be related to many factors, such as different timing of specimen collection, different susceptibility to this disease, sample sizes, as well as different detection methods and climate at the sampling locations, so the real reason regarding this difference is difficult to explain.…”

“…Hosts acquire giardiasis mainly through faecal-oral route, and show symptom of diarrhoea [6, 7]. Approximately 280 million people are diagnosed Giardia -infected per year worldwide [3, 8]. Moreover, large numbers of organisms have also been reported as hosts of G. intestinalis , including raccoon dogs [9].…”

“…Assemblages A and B are responsible for most of human infections and also infect a wide range of non-human hosts [3, 12] and assemblages C–H seem to be animal-specific [3, 13, 14]. Generally, assemblages C and D were commonly found in dogs, but were occasionally identified in humans [2, 3, 13, 14]. …”