Map showing sites of recent in vivo studies of chloroquine treatment for Plasmodium vivax infections in South America (published between 2000-2013). Triangles indicate study sites where treatment failures have been reported, while squares indicate sites with no treatment failures observed over 28 days of follow-up. Note the close proximity between two sites in Colombia (Uraba and Turbo) and two sites in Bolivia (Riberalta and Guayaramerín). Clinical data are from Villalobos-Salcedo et al. (2000)Villalobos-Salcedo JM, Tada MS, Kimura E, Menezes MJ, da Silva LHP 2000. In vivo sensitivity of Plasmodium vivax isolates from Rondônia (western Amazon Region, Brazil) to regimens including chloroquine and primaquine. Ann Trop Med Parasitol 94: 749-758. (Porto Velho, Brazil), Soto et al. (2001)Soto J, Toledo J, Gutierrez P, Luzz M, Llinas N, Cedeño N, Dunne M, Berman J 2001. Plasmodium vivax clinically resistant to chloroquine in Colombia. Am J Trop Med Hyg 65: 90-93. (Uraba and Llanos Orientales, Colombia), Baird et al. (2002)Baird JK, Tiwari T, Martin GJ, Tamminga CL, Prout TM, Tjaden J, Bravet PP, Rawlins S, Ferrel M, Carucci D, Hoffman SL 2002. Chloroquine for the treatment of uncomplicated malaria in Guyana. Ann Trop Med Parasitol
96: 339-348. (Georgetown, Guyana), Ruebush et al. (2003)Ruebush TK 2nd, Zegarra J, Cairo J, Andersen EM, Green M, Pillai DR, Marquiño W, Huilca M, Arévalo E, Garcia C, Solary L, Kain KC 2003. Chloroquine-resistant Plasmodium vivax malaria in Peru. Am J Trop Med Hyg
69: 548-552. (Iquitos, Caballococha and Sullana, Peru), Alvarez et al. (2006)Alvarez G, Piñeros JG, Tobón A, Ríos A, Maestre A, Blair S, Carmona-Fonseca J 2006. Efficacy of three chloroquine-primaquine regimens for treatment of Plasmodium vivax malaria in Colombia. Am J Trop Med Hyg 75: 605-609. (Turbo and El Bagre, Colombia), de Santana Filho et el. (2007) (Manaus, Brazil), Osorio et al. (2007)Osorio L, Pérez LP, González IJ 2007. Assessment of the efficacy of antimalarial drugs in Tarapacá, in the Colombian Amazon Basin. Biomedica
27: 133-140. (Tarapacá, Colombia), Carmona-Fonseca and Maestre (2009)Carmona-Fonseca J, Maestre A 2009. Prevention of Plasmodium vivax malaria recurrence: efficacy of the standard total dose of primaquine administered over 3 days. Acta Trop 112: 188-192. (Turbo and El Bagre, Colombia), Añez et al. (2012)Añez A, Navarro-Costa D, Yucra O, Garnica C, Melgar V, Moscoso M, Arteaga R, Nakao G 2012. Therapeutic response of Plasmodium vivax to chloroquine in Bolivia. Biomedica 32: 527-535. (Riberalta, Guayaramerín and Yacuiba, Bolivia) and Marques et al. (2013)Marques MM, Costa MR, Santana Filho FS, Vieira JL, Nascimento MT, Brasil LW, Nogueira F, Silveira H, Reyes-Lecca RC, Monteiro WM, Lacerda MV, Alecrim MG 2013. Plasmodium vivax chloroquine resistance and anemia in the western Brazilian Amazon. Antimicrob Agents Chemother 58: 342-347. (Manaus, Brazil). Shading patterns vary according to P. vivax malaria prevalence (PvPR) data estimated by Gething et al. (2012)Gething PW, Elyazar IR, Moyes CL, Smith DL, Battle KE, Guerra CA, Patil AP, Tatem AJ, Howes RE, Myers MF, George DB, Horby P, Wertheim HF, Price RN, Müeller I, Baird JK, Hay SI 2012. A long neglected world malaria map: Plasmodium vivax endemicity in 2010. PLoS Negl Trop Dis
6: e1814..