Multiple independent lineages of HIV-1 persist in breast milk and plasma

Design The origin and evolution of HIV-1 in breast milk is unclear, despite the continuing significance of this tissue as a transmitting compartment. To elucidate the evolutionary trajectory of viral populations in a transient mucosal compartment, longitudinal sequences of the envelope gp120 region from plasma and breast milk spanning the first year after delivery were analyzed in six women infected by HIV-1 subtype C.