Which types of hpv affect the cervix?

4 common bad types: The bad strains are hpv type 16, 18, 31, and 33. There are others, but not as common. Hpv type 11 causes warts.

You mean cancer ?: At the present time the primary cancer associated strains are 16/18/31 & 45. Strains 33/35/39/51/52/56/58 & 59 are also known to be associated with cancer but less prevalent. As research continues lesser strains will likely be added to the list. Whatever the strain, the need to do regular pap smears is unchanged by this data.