HIV Superinfection — A Rare Event?

HIV superinfection (in which a patient with established infection acquires a genetically different strain of the virus) has been documented but is considered quite rare. Some experts argue, though, that without repeat viral typing, many cases of superinfection may be missed, especially in patients with repeated unsafe sexual encounters.

Researchers analyzed 907 env and 672 gag sequences in 124 serum samples collected from 15 treatment-naive men in Amsterdam during periods of self-reported sexual risk (unprotected anal intercourse with at least two male partners, or a report of syphilis or gonorrhea, in the preceding 6 months). No cases of superinfection were detected during a median 5.8 person-years of follow-up.