Question: how many types of hpv cause genital warts?
Answer: Low-Risk Human Papillomavirus Warts may also appear in the mouth and throat. Two strains of HPV, types 6 and 11, cause 90 percent of these warts. Only about 1 percent of sexually active Americans have noticeable genital warts, which require treatment to prevent the spread to other genital areas and to sexual partners.