title: The epidemiological problem of diphtheria under conditions of low morbidity.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D003353:Corynebacterium diphtheriae / Q000302:isolation & purification / Q000378:metabolism / Q000472:pathogenicity*; D003604:Czechoslovakia; D004165:Diphtheria / Q000453:epidemiology* / Q000401:mortality; D004167:Diphtheria Toxin / Q000378:metabolism; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D014611:Vaccination; D014774:Virulence
chemical_list: D004167:Diphtheria Toxin