The Age-Related Cryptosporidium Species Distribution in Asymptomatic Cattle from North-Western Spain

Abstract

An age-related distribution of <i>Cryptosporidium</i> species has been reported in cattle, with <i>C. parvum</i> being predominant in suckling calves, <i>C. bovis</i> and <i>C. ryanae</i> being predominant in post-weaned calves and <i>C. andersoni</i> being predominant in adults. However, variants to this pattern have recently been reported. Thus, fecal samples (n = 594) from asymptomatic cattle were collected in north-western Spain. Animals were classified as <1 month (G1), 1-2 months (G2), 2-12 months (G3), 12-24 months (G4) and >2 years (G5). <i>Cryptosporidium</i> detection and species identification were performed by SSU rRNA PCR. Individual <i>Cryptosporidium</i> prevalence was 16.7%; it significantly decreased with age. <i>Cryptosporidium parvum</i> was predominant in G1 and <i>C. bovis</i> was predominant in the rest of the age classes; <i>C. bovis</i> and <i>C. ryanae</i> were especially prevalent in G2 and G3. <i>Cryptosporidium occultus</i> was not found in suckling calves. Finally, <i>C. andersoni</i> and <i>C. xiaoi</i> were occasionally detected in G5. The presence of <i>C. parvum</i> in all age classes implies significant animal and public health concerns. The predominance of <i>C. bovis</i> in cattle older than 1 month supports the idea that the age-related pattern of <i>Cryptosporidium</i> species described in cattle is not fully consistent, and thus further studies are still needed to identify those factors determining the species distribution.