Epidemiological Survey on EquineCryptosporidiumandGiardiaInfections in Italy and Molecular Characterization of Isolates

Abstract

Cryptosporidium and Giardia are two of the most common enteric pathogens of domestic and wild animals and humans. However, little is known on the prevalence, clinical manifestations and economic and zoonotic significance of these infections in horses. This study was undertaken to investigate the prevalence, excretion patterns and risk factors related to the faecal shedding of Cryptosporidium oocysts and Giardia cysts in horses and the zoonotic potential of species/genotypes isolated. The survey was performed on 120 foals and 30 broodmares reared in five Italian farms. Foals were divided in four homogeneous groups of 30 animals each (age classes: 0-2, 2-4, 4-8, >8 weeks). Three sequential faecal samples were collected from each animal and analysed by three techniques: direct fluorescent antibody test (DFA), faecal flotation (FF) and stained faecal smears (SFS). The DFA results showed a prevalence of 8% for Cryptosporidium and of 13.33% for Giardia; the prevalence values obtained by FF and SFS were lower and in poor agreement with DFA results. Giardia and Cryptosporidium infections were more common in foals (23.33% and 26.66% respectively) and higher excretions were observed in the youngest foals. Distribution of Cryptosporidium prevalence was statistically related to farms (P < 0.01), age of animals (P < 0.01), but was unrelated to the presence of diarrhoea. In the case of Giardia, the prevalence was only related to age (P < 0.01). Pattern sheddings were related to intestinal diseases and horse age (P < 0.01). Risk factors for shedding included residence farms and age older than 8 weeks for both parasites. All DFA-positive faecal samples were submitted to DNA extraction and PCR to determine Giardia and Cryptosporidium species/genotypes. Sequence analysis of the COWP gene of Cryptosporidium and of the SSU-rRNA gene of Giardia revealed that they were identical to each other and identified Cryptosporidium parvum and Giardia duodenalis assemblage E. The potential role of infected horses in zoonotic transmission of Cryptosporidium was supported by the findings of this study.

Cryptosporidium spp. infection in mares and foals of the northwest region of São Paulo State, Brazil

“…Cole et al (1998) reported diarrhea related to the presence of the above-mentioned protozoan, and Grinberg et al (2003) seemed to have evidenced this clinical sign in immunocompetent foals. In the present study, the consistency (p = 0.2119 and p = 0.2403) and color (p = 0.6842 and p = 0.5023) of feces were not associated with the occurrence of this disease in foals and mares, respectively, which agrees with the reports by Veronesi et al (2009) and Burton et al (2010).…”

“…Souza et al (2009) noted higher proportion of males naturally infected by Cryptosporidium spp. and concluded that the disease in equines, with different management types, is probably related to the immunological state and sanitary conditions found in the place where they live, since they were already considered sources of environmental infection (VERONESI et al, 2009). Concerning this aspect, it must be highlighted that, in previous epidemiological studies, Cryptosporidium spp.…”

“…Concerning this aspect, it must be highlighted that, in previous epidemiological studies, Cryptosporidium spp. infection was concentrated on one farm or site, and this may be due to the characteristics of the management adopted in the farm (VERONESI et al, 2009;BURTON et al, 2010).…”

“…in horses has drawn the attention of research worldwide (BURTON et al, 2010;COLE et al, 1998;JOHNSON et al, 1997;MAJEWSKA et al, 2004;MARQUES, 2010;SOUZA et al, 2009;VERONESI et al, 2009). Positive fecal samples for Cryptosporidium parvum oocysts were significantly greater for foals under six months of age and thoroughbreds compared to other breeds, in Texas (COLE et al, 1998).…”

“…has been associated with the presence of diarrhea in immunocompetent and immunodeficient animals (BJORNEBY et al, 1991;COLEMAN et al, 1989;GIBSON et al, 1983;GRINBERG et al, 2003;MAIR et al, 1990). Nevertheless, some clinical and epidemiological aspects of this infection are still not clear (VERONESI et al, 2009). Meireles (2010) discussed this situation in researches carried out in Brazil on domestic and wild animals infected with Cryptosporidium spp.…”