Prevalence of hydatid cysts in livestock from five regions of Jordan.

When the prevalences of cystic echinococcosis in indigenous sheep, goats, cattle and camels from five regions of Jordan were investigated, from March to December 1992, they were found to be 12.9%, 12.7%, 0.9% and 11%, respectively. They were substantially higher in sheep from Karak (27.6%) and in cattle from central Jordan (18.0% in Amman and 14.3% in Sahab) than in the same animals in other regions. Age-intensity data indicated that the parasite population is endemic in sheep and cattle and hyperendemic in goats. Infection rate increased steadily with age in sheep, but became constant in goats and cattle when they were about 2 years of age. The most common locations of cysts were the liver in sheep and goats and the lungs in cattle. Co-infection of the liver and lungs was common in sheep and cattle. Although the majority of the sheep, cattle and goats had 1-10 cysts, 20.4% of the sheep and 22.2% of the cattle had 11-50 and 11-30 cysts, respectively. Although 38.1% of the cysts in sheep were fertile, only 8.7% of the cattle cysts and 4.5% of the goat cysts were in this condition. The overall mean number of protoscolices/sheep cyst was 2.7 x 10(3); although the liver cysts had more protoscolices than the lung cysts (3.2 x 10(3) v. 1.9 x 10(3)/cyst), more of the lung cysts were viable (71.1% v. 62.3%). Some 0.2% of 13,436 sheep and 6.1% of 786 cattle imported live into Jordan were infected with hydatid cysts; 16.3% of the sheep cysts (61.4% viable) and 9.6% of the cattle cysts (76.1% viable) were fertile.