title: Evidence that a hydatid cyst is seldom "as old as the patient".
abstract: Human hydatid disease caused by the strain of Echinococcus granulosus endemic in Australia and New Zeland has been regarded as a very lonstanding condition, and most cysts diagnosed in adults were believed to have resulted from infection in childhood. A significant drop in the number of new cases among people and 25 and over (P less than 0.05) in two hydatid-control programmes makes it necessary to revise this view. In both Tasmania (P greater than 0.50) and New Zealand (0.50 greater than P greater than 0.10) the incidence was halved without significantly altering the age-distribution. These findings indicate that adults are relatively susceptible and that the latent period between infection and diagnosis in many cases is only a few years.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D001315:Australia; D001921:Brain / Q000469:parasitology; D001927:Brain Diseases / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D004443:Echinococcosis / Q000453:epidemiology* / Q000517:prevention & control; D004445:Echinococcosis, Pulmonary / Q000453:epidemiology; D006801:Humans; D007223:Infant; D008875:Middle Aged; D009520:New Zealand; D013997:Time Factors