News of the Day ... In Perspective04/02/2006
Influenza vaccine may give false positive HIV screen
A letter to the New England Journal of Medicine reports on a man who had a repeatedly positive immunoassay for HIV type 1 and an indeterminate Western blot after an occupational needle-stick injury. An HIV nucleic acid amplification test was repeatedly negative, and the Western blot reverted to negative. The patientís medical history was notable only for having received an influenza vaccine 11 days before presentation.
The author calls for increased awareness of this previously recognized cross-reactivity of various influenza strains. The time course is unknown (Erickson CP. N Engl J Med 2006;354:1422-1423).
More than 15 years ago, blood donation centers reported false positivity on screens for HIV-1, HTLV-1, and hepatitis C virus in donors that had received any brand of influenza vaccine. The test kits were implicated in that study. Duration of false positivity was 3 to 6 months (Simonsen L, et al. Am J Epidemiol 1995;141:1089-1096).