Occurrence of Cryptosporidium and other enteropathogens and their association with diarrhea in dairy calves of Buenos Aires province, Argentina

GARRO, CARLOS J.; MORICI, GABRIEL E.; TOMAZIC, MARIELA L.; VILTE, DANIEL; ENCINAS, MICAELA; VEGA, CELINA; BOK, MARINA; PARREÑO, VIVIANA; SCHNITTGER, LEONHARD

Veterinary Parasitology: Regional Studies and Reports

Elsevier

Año: 2021

2405-9390

Cryptosporidiosis of neonatal dairy calves causes diarrhea, resulting in important economic losses. In Argentina, prevalence values of Cryptosporidium spp. and other enteropathogens such as group A rotavirus (RVA), bovine coronavirus (BCoV) and enterotoxigenic Escherichia coli (ETEC, endotoxin STa+), have been independently studied in different regions. However, an integrative epidemiological investigation on large-scale farms has not been carried out. In this study, fecal samples (n = 908) were randomly collected from diarrheic and healthy calves from 42 dairy farms, and analyzed for the presence of Cryptosporidium spp., RVA, BCoV, ETEC (STa+) and Salmonella spp. In all sampled dairy farms, dams had been vaccinated against rotavirus and gram-negative bacteria to protect calves against neonatal diarrhea. The proportion of calves shedding Cryptosporidium spp., RVA, and BCoV in animals younger than 20 days of age were 29.8%, 12.4% and 6.4%, and in calves aged between 21 and 90 days, 5.6%, 3.9%, and 1.8%, respectively. ETEC was absent in the younger, and occurred only sporadically in the older group (0.9%), whereas Salmonella spp. was absent in both. The observed sporadic finding or even absence of bacterial pathogens might be explained by the frequent use of parenteral antibiotics in 25.3% and 6.5% of the younger and the older group of calves, respectively, within 2 days prior to sampling and/or vaccination of dams against gram-negative bacteria. Diarrhea was observed in 28.8% (95% CI, 24.7?32.8%) of the younger calves and 11.7% (95% CI, 9.1?15.5%) of the older calves. Importantly, Cryptosporidium spp. (odds ratio (OR) = 5.7; 95% CI, 3.3?9.9; p