Inclusion Criteria:  HIV uninfected MSM of 18 years or older using PrEP since at least 3 months HIV-infected MSM of 18 years or older  Exclusion Criteria for MSM using PrEP:  Any intervention in the (peri-) anal region in the past 3 months enema within 24h before sampling receptive anal sex within 24h before sampling current/ongoing peri-anal topical HPV-treatment  Exclusion Criteria for MSM infected with HPV:  none