title: A pseudo-outbreak of purified protein derivative skin-test conversions caused by inappropriate testing materials.
abstract: OBJECTIVE
  To investigate a cluster of newly identified tuberculosis infections.
  
  
  METHODS
  A field study was conducted including interviews; medical record reviews; checking of bills and invoices, pharmacy records, and drug manufacturer information; and clinical retesting.
  
  
  METHODS
  Community residential facilities providing comprehensive services to retarded adults.
  
  
  METHODS
  Twenty residential facility staff (not previously known to be purified protein derivative [PPD] positive).
  
  
  RESULTS
  Staff had been tested with 250 TU of PPD, and 9 of 20 were tuberculin positive. Retesting with 5 TU yielded no reaction.
  
  
  CONCLUSIONS
  Reactions were attributable to testing with a product not recommended for routine PPD screening. Healthcare workers planting PPD Mantoux tests always should check the vials to ensure that the appropriate strength solution is being used.
authors.affiliation: Bureau of Tuberculosis Control, New York State Department of Health, Albany 12237-0669, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: Grabau
authors.forename: D J
authors.initials: DJ
authors.lastname: Burrows
authors.forename: M L
authors.initials: ML
authors.lastname: Kern
mesh_terms: D000328:Adult; D004196:Disease Outbreaks; D005189:False Positive Reactions; D006801:Humans; D009518:New York; D012112:Residential Facilities; D014373:Tuberculin; D014374:Tuberculin Test / Q000592:standards*; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis* / Q000453:epidemiology
chemical_list: D014373:Tuberculin