<i>Plasmodium simium</i> : Population Genomics Reveals the Origin of a Reverse Zoonosis
Thaís C. de Oliveira, Priscila T. Rodrigues, Angela M. Early, Ana Maria Ribeiro de Castro Duarte, Julyana Cerqueira Buery, Marina Galvão Bueno, José Luiz Catão‐Dias, Crispim Cerutti, Luísa D. P. Rona, Daniel E. Neafsey, Marcelo U. Ferreira
Abstract
BACKGROUND: The population history of Plasmodium simium, which causes malaria in sylvatic Neotropical monkeys and humans along the Atlantic Coast of Brazil, remains disputed. Genetically diverse P vivax populations from various sources, including the lineages that founded the species P simium, are thought to have arrived in the Americas in separate migratory waves. METHODS: We use population genomic approaches to investigate the origin and evolution of P simium. RESULTS: We find a minimal genome-level differentiation between P simium and present-day New World P vivax isolates, consistent with their common geographic origin and subsequent divergence on this continent. The meagre genetic diversity in P simium samples from humans and monkeys implies a recent transfer from humans to non-human primates - a unique example of malaria as a reverse zoonosis of public health significance. Likely genomic signatures of P simium adaptation to new hosts include the deletion of >40% of a key erythrocyte invasion ligand, PvRBP2a, which may have favored more efficient simian host cell infection. CONCLUSIONS: New World P vivax lineages that switched from humans to platyrrhine monkeys founded the P simium population that infects nonhuman primates and feeds sustained human malaria transmission in the outskirts of major cities.