RESUMO
A retrospective survey of hospital cases to obtain baseline data on hydatid disease in the northwest of the Province of Chubut, Argentina, from 1973 to 1979 revealed annual mean rates that varied between 13.4 and 75.8 confirmed new cases per 100.000 population. Inclusion of data on parasitologically confirmed non-surgical cases and on the geographic origin of patients permitted a more accurate estimate of cases in the four Departments comprised in the study area. Information on cyst location, clinical status at admission, mortality, number of re-operations and length of hospitalization was obtained to assess the public health impact of hydatidosis within the area. The criteria established and methods used to collect this information are described and discussed.