Trends in HIV-1 protease mutations in Puerto Rico from 2002 to 2011.

<p><b>(A)</b> Normalized protease (PRO) mutation frequencies, color-coded as shown in the key, are shown for the 2002–2011 period. White boxes indicate an absence of PRO resistance mutations in any given year. PRO mutation frequency profiles are grouped using hierarchical clustering, revealing five distinct clusters. Mutation names are shown adjacent to the clustering plot. <b>(B)</b> Box-plot distributions of the normalized PRO mutation frequencies. Box-plots are color-coded using a rainbow scheme to visually distinguish the five PRO mutation frequency clusters.</p>