Prevalence and risk factors for shedding of Cryptosporidium spp. oocysts in dairy calves of Buenos Aires Province, Argentina

Abstract

In order to determine the prevalence and risk factors for shedding of Cryptosporidium spp. in dairy calves, a cross-sectional study was carried out in the northeastern region of Buenos Aires Province, Argentina. Fecal samples from a total of 552 calves from 27 dairy herds were collected, along with a questionnaire about management factors. Cryptosporidium spp. oocysts were detected by light microscopy using Kinyoun staining. Putative risk factors were tested for association using generalized linear mixed models (GLMMs). Oocyst shedding calves were found in 67% (CI95% = 49–84) of herds (corresponding to a true herd prevalence of 98%) and 16% (CI95% = 13–19) of calves (corresponding to a true calve prevalence of 8%). Within-herd prevalence ranged from 0 to 60%, with a median of 8%. Cryptosporidium spp. excretion was not associated with the type of liquid diet, gender, time the calf stayed with the dam after birth, use of antibiotics, blood presence in feces, and calving season. However, important highly significant risk factors of oocyst shedding of calves was an age of less or equal than 20 days (OR = 7.4; 95% CI95% = 3–16; P < 0.0001) and occurrence of diarrhea (OR = 5.5; 95% CI95% = 2–11; P < 0.0001). The observed association with young age strongly suggests an early exposure of neonatal calves to Cryptosporidium spp. oocysts in maternity pens and/or an age-related susceptibility. Association with diarrhea suggests that Cryptosporidium spp. is an important enteropathogen primarily responsible for the cause of the observed diarrheal syndrome. Results demonstrate that Cryptosporidium spp. infection is widespread in the study region. Monitoring and control of this parasitic protozoan infection in dairy herds is recommended.

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

“…Shedding of C. parvum oocysts was significantly associated with watery diarrhoea, mainly in calves younger than 2 weeks, which presented a higher probability of being positive than other animals; these results are in line with previous studies (Kváč et al 2006;Duranti et al 2009;Garro et al 2016). C. parvum is broadly recognised as the most pathogenic species for cattle, since it is responsible for the appearance of important neonatal diarrhoea outbreaks in farms (Santín et al 2004;Fayer et al 2006;Quílez et al 2008;Díaz et al 2010;Imre and Dărăbus 2011), although in some studies, it has also been identified as the major or the only species in healthy cattle (Santín et al 2004;Castro-Hermida et al 2011;Trotz-Williams et al 2006;Fayer et al 2007;Duranti et al 2009).…”

Prevalence of Cryptosporidium parvum in dairy calves and GP60 subtyping of diarrheic calves in central Argentina

“…Cryptosporidium parvum infection in calves is widespread (Brook et al 2008;Trotz-Williams et al 2008;Al Mawly et al 2015;Qi et al 2015), and also in the present study, C. parvum was, in agreement with previous reports in Argentina, the only species identified in calves (Tomazic et al 2013;Del Coco et al 2014). However, in contrast to previous studies done in Argentina, a considerably higher overall prevalence was found (Del Coco et al 2008;Tiranti et al 2011;Garro et al 2016), probably due to an additional oocysts concentration step prior to microscopic examination significantly increasing the sensitivity of oocyst detection. In the present study, the sampling fraction of calves ≤ 30 days of age was 83% (888/1073), which is the age range were C. parvum is most frequently found (Santín et al 2008;Xiao 2010;Ryan et al 2014).…”

“…Similar to the considerable differences of overall prevalence that have been reported, corresponding dissimilarities in herd prevalence may likewise be attributed to the different sensitivities of applied diagnostic test. Accordingly, Garro et al (2016) estimated a herd prevalence of 67% (overall prevalence 16.3%) compared with 89% (overall prevalence 26.3%) in the present study. Other factors that may bias towards lower herd prevalence values, maybe the sampling of a smaller age range or a higher number of older animals (30-60 days).…”

“…At least one C. parvum-positive calf was detected in 89% of the herds studied. Highly variable herd prevalence ranging from 50.5 to 96% have been reported (Hamnes et al 2006;Brook et al 2008;Trotz-Williams et al 2008;Silverlås et al 2009;Tiranti et al 2011;Smith et al 2014;Al Mawly et al 2015;Delafosse et al 2015;Garro et al 2016;Avendaño et al 2018). Similar to the considerable differences of overall prevalence that have been reported, corresponding dissimilarities in herd prevalence may likewise be attributed to the different sensitivities of applied diagnostic test.…”

Invited review: A systematic review of the effects of early separation on dairy cow and calf health

“…Although the balance of the research seems to point to either neutral or positive effects of dam rearing on calf scours, results are mixed with respect to Cryptosporidium (see Table 2). Two of the 9 included studies reported a protective effect of the dam's presence (Kvac et al, 2006;Duranti et al, 2009), 4 reported no difference (Maldonado Camargo et al, 1998;Mohammed et al, 1999;Delafosse et al, 2015;Garro et al, 2016), and the remaining 3 (Quigley et al, 1994;Trotz-Williams et al, 2007, 2008a indicated that dam-calf contact increases the risk of infection. This lack of consensus may stem from variation in study design and outcome measurements (e.g., herd versus sample-level prevalence), in breed (dairy versus mixed dairy-beef), or in the diagnostic methods chosen.…”