Hydatids : a disease of human carelessness in New Zealand

Hydatid disease caused by the parasite Echinococcus granulosus first became a human health problem in New Zealand in the late nineteenth century. Humans contract this potentially fatal disease by handling dogs that have eaten infected sheep carcasses. The disease is controlled by feeding dogs correctly and preventing them from straying. New Zealand's mild climate and large sheep population proved an ideal breeding ground for the parasite. Doctors and veterinarians understood the transmission of the disease, but for many years dog owners ignored their advice on prevention by continuing to feed their dogs on raw sheep offal. This study examines the unexpected difficulties New Zealand encountered in its campaign to eradicate hydatids. Until the late 1950s neither public education nor legislation had any apparent effect. The rising incidence of the disease, notably in children, finally shocked farmers and the public into demanding government action. The Government agreed in 1959 to support a national control campaign, anticipating that eradication would be achieved within three to five years. This study explains how the problem proved far more complex than officials had anticipated, and why a successful outcome took as much as thirty-five further years to achieve. But by the mid-1990s New Zealand could at last claim that it had virtually exterminated this dangerous and elusive parasite