Plasmodium vivax is the leading cause of human malaria in Asia and Latin America but is absent from most of central Africa due to the near fixation of a mutation that inhibits the expression of its receptor, the Duffy antigen, on human erythrocytes. The emergence of this protective allele is not understood because P. vivax is believed to have originated in Asia. Here we show, using a non-invasive approach, that wild chimpanzees and gorillas throughout central Africa are endemically infected with parasites that are closely related to human P. vivax. Sequence analyses reveal that ape parasites lack host specificity and are much more diverse than human parasites, which form a monophyletic lineage within the ape parasite radiation. These findings indicate that human P. vivax is of African origin and likely selected for the Duffy-negative mutation. All extant human P. vivax parasites are derived from a single ancestor that escaped out of Africa.
Bibliographical noteFunding Information:
We thank the staff of project PRESICA, the World Wildlife Fund for Nature (WWF/ DRC), the Institut National de Recherches Biomédicales (INRB, Kinshasa, DRC), Global Viral Cameroon, the Bonobo Conservation Initiative and Vie Sauvage, as well as Didier Mazongo, Octavie Lunguya, Muriel Aloni and Valentin Mbenz for fieldwork in Cameroon and the DRC; field assistants in Gombe National Park and Ugalla for sample collection in Tanzania, the staff of the Sanaga Yong, Limbe and Ape Action Africa/Mfou National Park Wildlife Rescue Centres for collecting blood samples from captive apes; the Cameroonian Ministries of Health, Forestry and Wildlife, and Scientific Research and Innovation for permission to collect samples in Cameroon; the Water and Forest Ministry for permission to collect samples in the Central African Republic; the Ministry of Forest Economy and Sustainable Development for permission to collect samples in the Republic of Congo; the Ministry of Scientific Research and Technology, the Department of Ecology and Management of Plant and Animal Resources of the University of Kisangani, the Ministries of Health and Environment and the National Ethics Committee for permission to collect samples in the DRC; the Tanzania Commission for Science and Technology and the Tanzania Wildlife Research Institute for permission to conduct research in Gombe National Park and Ugalla. This work was supported by grants from the National Institutes of Health (R01 AI091595, R37 AI050529, R01 AI58715, T32 AI007532, P30 AI045008), the Agence Nationale de Recherche sur le Sida (ANRS 12125/ 12182/12255), the Agence Nationale de Recherche (Programme Blanc, Sciences de la Vie, de la Santé et des Ecosystémes and ANR 11 BSV3 021 01, Projet PRIMAL), Harvard University, the Arthur L. Greene Fund, the Jane Goodall Institute, the Wellcome Trust (098051), the Leakey Foundation, Google.org and the Skoll Foundation. This study was also made possible by the generous support of the American people through the United States Agency for International Development (USAID) Emerging Pandemic Threats PREDICT. The contents are the responsibility of the authors and do not necessarily reflect the views of USAID or the United States Government.
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