The 6-month risk of HPV persistence among men with high-viral load infections in the glans at baseline was lower in the circumcision arm , compared with the control arm , for HPV-16 ( risk ratio [ RR ] , 0.36 [ 95 % CI , .18 -.72 ] ) and HPV-18 ( RR 0.34 [ 95 % CI , .13 -.86 ] ) .