KINSHASA, Congo—As Congo copes with its biggest outbreak of mpox, scientists warn discrimination against gay and bisexual men on the continent could make it worse. In November, the World Health Organization reported that mpox, also known as monkeypox, was being spread via sex in Congo for the first time. That is a significant departure from previous flare-ups, where the virus mainly sickened people in contact with diseased animals. Mpox has been in parts of Central and West Africa for decades, but it was not until 2022 that it was documented to spread via sex; most of the 91,00 people infected in approximately 100 countries that year were gay or bisexual men. In Africa, unwillingness to report symptoms could drive the outbreak underground, said Dimie Ogoina, an infectious diseases specialist at the Niger Delta University in Nigeria.