Epidemiology of hydatidosis/echinococcosis in Ouarzazate, the pre-Saharian region of Morocco.

In the Ouarzazate province of Southern Morocco, 1085 cattle and 358 sheep were examined for hydatid cysts. The prevalence was 44.6% (range 8.3-83.4%) in cattle and 5.3% (range 1.3-28.6%) in sheep. The prevalence increased with the age of the animals. The lung was the predominant site of infection, followed by the liver. In cattle, 14.2% of hydatid cysts were fertile and 16.4% had degenerative changes. The mean loss per head of cattle slaughtered was about 1 kg of liver and 900 g of lungs in the urban abattoirs. In monetary terms at the current price of 1980, this meant a loss of U.S. +4.5 at urban and +1.6 at rural abattoirs. The mean prevalence of infection in 61 stray dogs was 50.8%, with a mean worm burden of 413. The urban dogs had a lower infection rate (42.9%) than the rural dogs (61.5%). There were 130 dogs per 1000 inhabitants. The human population was ignorant of the life-cycle of Echinococcus granulosus and was not aware of risk of infection through dogs. Dogs become infected at abattoirs, at home slaughter and in the field by consuming dead carcasses. The maintenance and transmission of E. granulosus in animals and man is related to social, religious and cultural factors.