Common occurrence of Cryptosporidium hominis in asymptomatic and symptomatic calves in France

Abstract

BackgroundCryptosporidium spp. infections are the most frequent parasitic cause of diarrhea in humans and cattle. However, asymptomatic cases are less often documented than symptomatic cases or cases with experimentally infected animals. Cryptosporidium (C.) hominis infection accounts for the majority of pediatric cases in several countries, while C. parvum is a major cause of diarrhea in neonatal calves. In cattle Cryptosporidium spp. infection can be caused by C. parvum, C. bovis, C.andersoni and C. ryanae, and recently, reports of cattle cases of C. hominis cryptosporidiosis cases suggest that the presence of C. hominis in calves was previously underestimated.Methodology/Principal findingsFrom February to November 2015, Cryptosporidium spp. infected calves were detected in 29/44 randomly included farms from 5 geographic regions of France. C. hominis and C. parvum were found in 12/44 and 26/44 farms, respectively with higher C. hominis prevalence in the western region. In 9 farms, both C. parvum and C. hominis were detected. Eighty-six of 412 (73/342 asymptomatic and 13/70 symptomatic) one to nine-week-old calves shed C. hominis or C. parvum oocysts (15 and 71 calves, respectively), with no mixed infection detected. The predominant C. hominis IbA9G3 genotype was present in all regions, and more frequent in the western region. An incompletely characterized Ib, and the IbA13G3, IbA9G2 and IbA14G2 genotypes were present only in the western region. For C. parvum, the most frequent genotype was IIaA16G3R1 with no geographic clustering. Most C. hominis infected calves were asymptomatic, with some exceptions of IbA9G2 and IbA9G3 isolates, while C. parvum IIaA16G3R1 was associated with symptoms.Conclusions/SignificancePresent results indicate for the first time that in several geographic regions of France, C. hominis was present in about one fifth of both asymptomatic and symptomatic infected calves, with isolated genotypes likely associated with human infection. Further investigations are aimed at documenting direct or indirect transmissions between livestock and humans.

Asymptomatic Cryptosporidium infections in ewes and lambs are a source of environmental contamination with zoonotic genotypes of Cryptosporidium parvum

“…Likewise, C. hominis was detected neither in lambs nor in ewes. In rare cases, it can infect goats and sheep [ 15 ] but is found with a higher prevalence in calves [ 38 ]. As the studied farms were mixed farms with both dairy sheep and meat cattle, we had expected to detect C. hominis, but this was not the case.…”

“…All samples were analyzed by molecular methods for species identification, and positive samples were genotyped in a second step. Samples were prepared as described by Razakandrainibe and colleagues [ 38 ]. Briefly, 250 mg of feces were pre-treated using mechanical lysis in Lysing Matrix A Tubes (Qiagen, CA, USA), thermal shock lysis and sonication before isolating DNA from the pre-treated samples using a modified QIAmp Stool Mini Kit (Qiagen, CA, USA).…”

“…The major sources of contamination for humans are drinking and recreational waters contaminated by livestock [ 11 ] or infected humans. However, few clinical human cryptosporidiosis cases can be explained by environmental contamination with sheep and goat manure due to the difficulty of tracking down the initial source of contamination [ 38 ]. In their model, Vermeulen and colleagues [ 49 ] estimated the Cryptosporidium oocyst loads in livestock manure and predicted that it was the main source of environmental contamination in Europe and North America.…”

Molecular characterization of Cryptosporidium isolates from diarrheal dairy calves in France

“…Thus far, four common Cryptosporidium species have been identified in cattle: C. parvum, C. bovis, C. ryanae, and C. andersoni, but only C. parvum is associated with clinical disease in neonatal calves, as older animals (> 6 weeks) exhibit asymptomatic oocyst shedding (Silverlås et al, 2013). The recent observation of C. hominis in symptomatic and asymptomatic calves in France (Razakandrainibe et al, 2018) emphasises the importance of identifying which Cryptosporidium species is shed by calves. The calves included in this study were all younger than 45 days, thus the finding that 100% of animals were infected with C. parvum via 18S rRNA gene based-PCR-RFLP was similar to previous studies demonstrating high C. parvum occurrence in preweaned calves (Kvác et al, 2006;Santín et al, 2004).…”

Molecular characterisation and risk factor analysis of Cryptosporidium spp. in calves from Italy

“…C. parvum is also an important zoonotic species because together with C. hominis, it is involved in most cases of cryptosporidiosis in humans (Xiao 2010). Given that some recent investigations suggest an increasing importance of C. hominis in bovines (Zahedi et al 2016;Razakandrainibe et al 2018), cattle may play an important role as reservoirs of Cryptosporidium species causing human cryptosporidiosis. Cryptosporidial infection is transmitted by the faecal-oral route, and the majority of human cases are waterborne (Fayer et al 2000;Olson et al 2004).…”