Some countries in Africa "still rely on dichlorodiphenyltrichloroethane (DDT) for [malaria] vector control," therefore "[i]t is ... problematic that the U.N. Environment Programme (UNEP), without the consent of member states, and violating its own treaties, exerts relentless pressure to ban DDT globally," Richard Tren, director of Africa Fighting Malaria, and Richard Nchabi Kamwi, Nambia's minister of health and social services, write in a BMJ opinion piece. Nineteen countries reserve the right to use DDT under the 2000 Stockholm Convention, which "made an exception for DDT in disease vector control," and the WHO endorses DDT, "arguing that a premature shift to less effective or more costly alternatives will have a negative impact on disease burden," the authors state.