title: Immunity against infectious diseases: predictive value of self-reported history of vaccination and disease.
abstract: OBJECTIVE
  To determine whether self-reported history of disease and/or vaccination is predictive of immunity against hepatitis B, varicella, rubella, mumps, and measles.
  
  
  METHODS
  The seroprevalence of viral antibodies and the predictive value of a self-report questionnaire were determined for 616 paramedical students who matriculated into Padua Medical School (Padua, Italy) during 2003-2005.
  
  
  RESULTS
  The majority of subjects (86.9%) remembered being vaccinated against hepatitis B but had no recollection of disease. Among vaccinees, 1.5% showed markers of previous infection, 6.7% tested negative for anti-hepatitis B virus surface antigen (anti-HBsAg) antibodies, and 91.8% tested positive for anti-HBsAg. Self-reported vaccination history had a positive predictive value of 93.2% for test results positive for immunity against hepatitis B. Immunity against varicella (93.7% of subjects) and rubella (95.5%) was high, compared with immunity against mumps (79.9%) and measles (83.1%). In addition, results of tests for detection of immunity against mumps and measles were equivocal for more than 7% of subjects, probably because their vaccination regimen was not completed. Self-reported histories of varicella disease and rubella disease and vaccination had high positive predictive values (greater than 98% each) for testing positive for antiviral antibodies, compared with self-reported histories of mumps disease and vaccination and measles disease and vaccination; however, high positive predictive values were observed for self-reported histories of mumps only (92.0%) and measles only (94.7%).
  
  
  CONCLUSIONS
  The self-report questionnaire used in this study did not accurately predict immunity against 5 transmittable but vaccine-preventable diseases. A complete serological evaluation of healthcare workers, followed by vaccination of those with negative or equivocal results of serological tests, is an appropriate measure to decrease the risk of infection in this population.
authors.affiliation: Department of Environmental Medicine and Public Health, University of Padova, Padova, 35128, Italy. andrea.trevisan@unipd.it
authors.forename: Andrea
authors.initials: A
authors.lastname: Trevisan
authors.forename: Clara
authors.initials: C
authors.lastname: Frasson
authors.forename: Marta
authors.initials: M
authors.lastname: Morandin
authors.forename: Michela
authors.initials: M
authors.lastname: Beggio
authors.forename: Alberto
authors.initials: A
authors.lastname: Bruno
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Davanzo
authors.forename: Livio
authors.initials: L
authors.lastname: Di Marco
authors.forename: Livio
authors.initials: L
authors.lastname: Simioni
authors.forename: Guglielmo
authors.initials: G
authors.lastname: Amato
mesh_terms: D000328:Adult; D000914:Antibodies, Viral / Q000097:blood* / Q000145:classification; D000954:Antigens, Surface / Q000097:blood; D002644:Chickenpox / Q000276:immunology* / Q000517:prevention & control; D003141:Communicable Diseases / Q000276:immunology / Q000821:virology; D005260:Female; D006509:Hepatitis B / Q000276:immunology* / Q000517:prevention & control; D006801:Humans; D007109:Immunity; D007124:Immunoenzyme Techniques; D007558:Italy / Q000453:epidemiology; D008297:Male; D011237:Predictive Value of Tests; D011594:Psychometrics / Q000379:methods*; D012327:RNA Virus Infections / Q000276:immunology* / Q000517:prevention & control; D012650:Self Disclosure; D016036:Seroepidemiologic Studies; D013336:Students, Health Occupations / Q000523:psychology / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D014611:Vaccination / Q000145:classification / Q000706:statistics & numerical data*
chemical_list: D000914:Antibodies, Viral; D000954:Antigens, Surface