Prevalence and abundance of Eimeria spp. infection in captive vicuñas (Vicugna vicugna) from the Argentinean Andean Altiplano

Two hundred and thirty-five faecal samples from adult and young captive vicuñas from the Abra Pampa Experimental Station of the National Agricultural Technology Institute (Jujuy Province, Argentina) were obtained in May and November 2011 in order to study the prevalence and abundance of Eimeria spp. Faeces were individually assessed by two methods: the modified Mc Master technique for the diagnosis of the smaller Eimeria species: E. punoensis, E. alpacae and E. lamae and the sedimentation-flotation technique for the detection of the bigger Eimeria species: E. macusaniensis and E. ivitaensis. The five species of Eimeria of South American camelids were found in the vicuñas population with prevalence ranging from >65% (E. punoensis and E. alpacae in both ages and also E. macusaniensis in young vicuñas) to <2% (E. ivitaensis in both ages). The juveniles showed both higher prevalence and mean abundance than adults for most coccidian species, except for E. ivitaensis. E. punoensis exhibited the highest prevalence in young and adult vicuñas whereas the highest mean abundance in juveniles was due to E. lamae (May) and E. punoensis (November). In adult vicuñas, smaller Eimeria had a higher prevalence and mean abundance than the bigger ones for both sampling dates. Most (>70%) of adult and young vicuñas were concurrently infected by two to four Eimeria species. Despite the high oocysts' outputs in some juveniles no clinical signs of coccidiosis were seen in them. The epidemiological patterns of Eimeria spp. infections in vicuñas are discussed.