Preventable mix-ups of tuberculin and vaccines: reports to the US Vaccine and Drug Safety Reporting Systems.
BACKGROUND
Errors involving the mix-up of tuberculin purified protein derivative (PPD) and vaccines leading to adverse reactions and unnecessary medical management have been reported previously.


OBJECTIVE
To determine the frequency of PPD-vaccine mix-ups reported to the US Vaccine Adverse Event Reporting System (VAERS) and the Adverse Event Reporting System (AERS), characterize adverse events and clusters involving mix-ups and describe reported contributory factors.


METHODS
We reviewed AERS reports from 1969 to 2005 and VAERS reports from 1990 to 2005. We defined a mix-up error event as an incident in which a single patient or a cluster of patients inadvertently received vaccine instead of a PPD product or received a PPD product instead of vaccine. We defined a cluster as inadvertent administration of PPD or vaccine products to more than one patient in the same facility within 1 month.


RESULTS
Of 115 mix-up events identified, 101 involved inadvertent administration of vaccines instead of PPD. Product confusion involved PPD and multiple vaccines. The annual number of reported mix-ups increased from an average of one event per year in the early 1990s to an average of ten events per year in the early part of this decade. More than 240 adults and children were affected and the majority reported local injection site reactions. Four individuals were hospitalized (all recovered) after receiving the wrong products. Several patients were inappropriately started on tuberculosis prophylaxis as a result of a vaccine local reaction being interpreted as a positive tuberculin skin test. Reported potential contributory factors involved both system factors (e.g. similar packaging) and human errors (e.g. failure to read label before product administration).


CONCLUSIONS
To prevent PPD-vaccine mix-ups, proper storage, handling and administration of vaccine and PPD products is necessary.
Office of Biostatistics and Epidemiology, US Food and Drug Administration (FDA), 1401 Rockville Pike, Rockville, MD 20852, USA. sojuchang@hotmail.com
Soju
S
Chang
Vitali
V
Pool
Kathryn
K
O'Connell
Jacquelyn A
JA
Polder
John
J
Iskander
Colleen
C
Sweeney
Robert
R
Ball
M Miles
MM
Braun
D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D008297:Male; D008508:Medication Errors / Q000517:prevention & control*; D008875:Middle Aged; D011358:Product Surveillance, Postmarketing; D014373:Tuberculin / Q000009:adverse effects*; D014481:United States / Q000453:epidemiology; D014612:Vaccines / Q000009:adverse effects*; D055815:Young Adult
D014373:Tuberculin; D014612:Vaccines