Evaluation of rubella IgM enzyme immunoassays.
BACKGROUND
Rubella virus generally causes a mild fever, rash illness similar in clinical presentation to infections by other viruses including measles and parvovirus B19. Rubella infections in pregnant women in the first trimester carry a high risk of congenital rubella syndrome (CRS) which can result in severe congenital defects in the infants. The goal of rubella immunization programs is therefore to eliminate CRS. The primary test for the laboratory confirmation of rubella is IgM serology. It is therefore important to evaluate currently available commercial rubella IgM immunoassays to ensure high quality rubella diagnostic testing.


METHODS
In this study, we compared the performance of seven commercial rubella IgM enzyme immunoassays (EIA) (Meddens, Denka Seiken, Behring, Wampole, Captia, Sigma and Abbott Axsym) using well-defined panels of sera from rubella and non-rubella/rash-illness cases.


RESULTS
The Meddens, Denka Seiken, Behring and Wampole rubella IgM EIAs all performed similarly for sensitivity (range of 74.1-76.8%) and specificity (range of 93.9-96.1%). Relative to the other assays, the Axsym had a higher sensitivity (78.9%) but lower specificity (86.5%). The Captia assay had the lowest overall sensitivity (66.4%), while the Sigma assay had a lower specificity (85.6%) in relation to the other assays.


CONCLUSIONS
In conclusion, the Meddens, Denka Seiken, Behring and Wampole rubella IgM EIAs are comparable in their overall performance with respect to sensitivity and specificity.
Tipples
Graham A
GA
National Microbiology Laboratory, Health Canada, Winnipeg, Manitoba, Canada. graham_tipples@hc-sc.gc.ca
Hamkar
Rasool
R
Mohktari-Azad
Talat
T
Gray
Michael
M
Ball
Jennifer
J
Head
Carol
C
Ratnam
Samuel
S
D000914:Antibodies, Viral / Q000097:blood*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods*; D007075:Immunoglobulin M / Q000097:blood*; D011933:Reagent Kits, Diagnostic; D012409:Rubella / Q000175:diagnosis*; D012412:Rubella virus / Q000276:immunology; D012680:Sensitivity and Specificity
D000914:Antibodies, Viral; D007075:Immunoglobulin M; D011933:Reagent Kits, Diagnostic