Karel is a Leader for the International Indigenous Working Group on HIV & AIDS (IIWGHA), and a board member of the international organization ÉGIDES (International Francophone Alliance for Equality and Diversities) based in Canada.
Karel has been an activist for LGBTQ+ rights for over 25 years, beginning in 1997 with the Homosphere association in New Caledonia. Today, in French Polynesia, Karel is president of the LGBTQ+ organization Cousins Cousines de Tahiti and member of the board of local AIDS organization Agir contre le SIDA. Karel is also Vice President of the regional organization Alliance LGBT+ Franco Océanienne and a representative to the International Lesbian, Gay, Bisexual, Trans and Intersex Association OCEANIA (ILGA Oceania). Karel engages in HIV prevention activities through the various LGBTQ+ and AIDS groups in which he holds posts.