Natural foci of infection of some helminthiases.
D004443:Echinococcosis / Q000453:epidemiology*; D006373:Helminthiasis / Q000453:epidemiology*; D006801:Humans; D014235:Trichinellosis / Q000453:epidemiology*
ECHINOCOCCOSIS/epidemiology; HELMINTHIASIS/epidemiology; TRICHINOSIS/epidemiology