PubMed1973
A century ago Iceland had the highest prevalence of human hydatid disease ever recorded anywhere. Since 1864 the disease has been gradually controlled, and today there is less than one new case per decade. The sheep population of about one million, over 95% of which is subject to inspection at slaughter, has yielded only 15 infected animals in the last 20 years. In most districts farm slaughtering still persists, though on a very limited scale, and farm dogs are subjected to very little control. The main credit for the remarkable control of E. granulosus is given to education, but many accidental social and environmental factors, peculiar to Iceland, contributed to the result. Of these, the most notable were the small human population and high rate of literacy; the very high dog mortality from distemper in the 19th century, which coincided with a major export trade in live sheep; the custom of feeding dogs on cooked household scraps, the risk of infection being confined to the short sheep slaughtering season and the rare occasions when a cow or pig is slaughtered; the absence of employed labour on Icelandic farms, all slaughtering being done by the owner, an educated man with middle-class values; the change in animal husbandry since 1920 towards the slaughter of 5-month-old lambs, too young to have viable cysts; and the meat subsidy, which since 1947 has led to the use of abattoirs for all but a handful of uneconomic animals kept for slaughter on the farm.