TY - JOUR T1 - Long-term sustained malaria control leads to inbreeding and fragmentation of <em>Plasmodium vivax</em> populations JF - bioRxiv DO - 10.1101/100610 SP - 100610 AU - Andreea Waltmann AU - Cristian Koepfli AU - Natacha Tessier AU - Stephan Karl AU - Andrew W Darcy AU - Lyndes Wini AU - G.L. Abby Harrison AU - CĂ©line Barnadas AU - Charlie Jannison AU - Harin Karunajeewa AU - Sarah Boyd AU - Maxine Whittaker AU - James Kazura AU - Melanie Bahlo AU - Ivo Mueller AU - Alyssa E. Barry Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/01/15/100610.abstract N2 - Plasmodium vivax populations are more resistant to malaria control strategies than Plasmodium falciparum, maintaining high genetic diversity and gene flow even at low transmission. To quantify the impact of declining transmission on P. vivax populations, we investigated population genetic structure over time during intensified control efforts and over a wide range of transmission intensities and spatial scales in the Southwest Pacific. Analysis of 887 P. vivax microsatellite haplotypes (Papua New Guinea, PNG = 443, Solomon Islands = 420, Vanuatu =24) revealed substantial population structure among countries and modestly declining diversity as transmission decreases over space and time. In the Solomon Islands, which has had sustained control efforts for 20 years, significant population structure was observed on different spatial scales down to the sub-village level. Up to 37% of alleles were partitioned between populations and significant multilocus linkage disequilibrium was observed indicating substantial inbreeding. High levels of haplotype relatedness around households and within a range of 300m are consistent with a focal and clustered infections suggesting that restricted local transmission occurs within the range of vector movement and that subsequent focal inbreeding may be a key factor contributing to the observed population structure. We conclude that unique transmission strategies, including relapse allows P. vivax populations to withstand pressure from control efforts for longer than P. falciparum. However sustained control efforts do eventually impact parasite population structure and with further control pressure, populations may eventually fragment into clustered foci that could be targeted for elimination. ER -