The role of cattle in the epidemiology of Echinococcus granulosus in an endemic area of southern Italy.

An epidemiological and molecular survey was conducted to investigate the role of cattle in the transmission chain of cystic echinococcosis (CE) in the Campania region of southern Italy. Out of a total of 434 cattle examined for CE, 45 (10.4%) were found infected. A total of 363 cysts were collected from the infected animals: 239 in the liver and 124 in the lungs. The cysts were either sterile (42.7%) or calcified/caseous (57.3%); no fertile cysts were found. Most of the cysts had sizes <3 cm (77.1%) and were unilocular (78.8%). The results of the linear regression model did not show any significant correlation between the age of infected cattle and the number of cysts. The sequencing of the mitochondrial cytochrome C oxidase subunit 1 (CO1) gene of 40 hydatid cysts produced sequences of 419 bp for each sample analyzed. Alignment of the obtained sequences with those present in GenBank showed 100% identity with the common sheep G1 (n=21 cysts), the Tasmanian sheep G2 (n=2 cysts), and the buffalo G3 (n=17 cysts) strains, which constitute the species Echinococcus granulosus sensu stricto. The findings reported in the present study show that CE is widespread in cattle bred in the Campania region of southern Italy. However, the absence of fertile cysts and of the cattle strain (G5, E. ortleppi) suggests that cattle would not have any role in the persistence of this important zoonosis but rather a role as indicators of CE infection in this endemic area.