RT Journal Article SR Electronic T1 STIs during the first and second wave of COVID-19 in Denmark JF Sexually Transmitted Infections JO Sex Transm Infect FD BMJ Publishing Group Ltd SP sextrans-2021-055021 DO 10.1136/sextrans-2021-055021 A1 Ida M Heerfordt YR 2021 UL http://sti.bmj.com/content/early/2021/03/18/sextrans-2021-055021.abstract AB