Widespread resistance to ACTs in Africa

Over the last century all monotherapies (quinine, chloroquine, mefloquine, lumefantrine, piperaquine, pyrimethamine, halofantrine) have lead to rapid resistances of Plasmodium falciparum. Combination therapy betweeen artemisinin and molecules with long lasting action had raised optimism. But already in 2003 first signs of resistance developed in South-East Asia. It has been established meanwhile that they were mostly related to mutations in the kelch13 propeller region of the parasite. Mutations have meanwhile raised to 90%. Timothy J.C. Anderson, Shalini Nair, Marina McDew-White, Ian H. Cheeseman, Standwell Nkhoma, Fatma Bilgic, Rose McGready, Elizabeth Ashley, Aung Pyae Phyo, Nicholas J. White, François Nosten. Why are there so many independent origins of artemisinin resistance in malaria parasites? preprint first posted online May. 31, 2016; doi: http://dx.doi.org/10.1101/056291. Artemisinin resistance in Plasmodium falciparum has emerged in South-East Asia and now poses a threat to the control and elimination of malaria. Mapping the geographic extent of resistance is essential for planning containment and elimination strategies. But the problem is not limited to South-East Asia. Signs of arteminisin resistance have developed in other continents, in at least a dozen African countries. Researchers from the London School of Hygiene and Tropical Medicine have discovered a new genetic mutation in Plasmodium falciparum, the parasite that causes malaria, which may mean the beginning of drug-resistant malaria in Africa. The mutated gene, ap2mu, makes the parasite less sensitive to artemisinin, an anti-malarial drug that is the most effective treatment available. In 2013, the same school led a study that showed a link between ap2mu genetically mutating and malaria parasites growing resistant to treatments; Kenyan children with malaria of this mutation still had the parasites in their blood after receiving malaria treatments. Published on Monday, Apr 20, 2015 @ 12:19pm by Vaccine News Reports In Senegal while no mutation was found in the propeller region of K13 in parasites from Dakar in 2012 and 2013, three mutations (5.5%) were identified in this domain in 2013 and 2014. As a result, surveillance of K13 polymorphisms must be implemented. Agathe Boussaroque, Bécaye Fall, Marylin Madametb, Cheikhou Camaraf, Nicolas Benoit, Mansour Fall, Aminata Nakoulimah, Pierre Dionnei,. Emergence of Mutations in the K13 Propeller Gene of Plasmodium falciparum Isolates from Dakar, Senegal, in 2013-2014. Antimicrob. Agents Chemother. January 2016 vol. 60 no. 1 624-627 doi: 10.1128/AAC.01346-15 Lo AC, Faye B, Ba el-H, Cisse B, Tine R, Abiola A, Ndiaye M, Sutherland C, Gaye O. Prevalence of molecular markers of drug resistance in an area of seasonal malaria chemoprevention in children in Senegal. Malar J. 2013 Apr 23;12:137. doi: 10.1186/1475-2875-12-137. In Kenya a research team looked for mutations in the Plasmodium falciparum K13 propeller gene of an artemisinin-resistant parasite on islands in Lake Victoria, Kenya, where transmission in 2012-2013 was high. The 4 new types of nonsynonymous, and 5 of synonymous, mutations we detected among 539 samples analyzed provide clues to understanding artemisinin-resistant parasites. Isozumi R, Uemura H, Kimata I, Ichinose Y, Logedi J, Omar AH, Kaneko A. Novel mutations in K13 propeller gene of artemisinin-resistant Plasmodium falciparum. Emerg Infect Dis. 2015 Mar;21(3):490-2. doi: 10.3201/eid2103.140898. A recent study provides baseline prevalence of K13-propeller mutations in sub-Saharan Africa with samples collected in the past few months. This baseline information will be critical in tracking the emergence and/or spread of P. falciparum resistance to artemisinin in sub-Saharan Africa. There is now an important need for local studies of clinical resistance to artemisinin and for in vitro and ex vivo to clarify the significance of K13-propeller mutations as markers of artemisinin resistance Africa. A total of 1212 P. falciparum samples collected from 12 countries were sequenced. None of the K13-propeller mutations previously reported in Southeast Asia were found, but 22 unique mutations were detected. Edwin Kamau, Susana Campino, Lucas Amenga-Etego, Eleanor Drury, Deus Ishengoma, Kimberly Johnson, Dieudonne Mumba, Mihir Kekre, William Yavo, Daniel Mead, Marielle Bouyou-Akotet, Tobias Apinjoh, Lemu Golassa, Milijaona Randrianarivelojosia, K13-Propeller Polymorphisms in Plasmodium falciparum Parasites From Sub-Saharan Africa. J Infect Dis. 2016 January 15; 213(2): 327. doi: 10.1093/infdis/jiu608 Kamau E, Akala HM, Achieng AO, Yeda R, Ogutu B. Case report of attenuated responsiveness to Coartem in Western Kenya. Int J Med Pharm Case Rep 2:5-9 In Rwanda no polymorphisms were observed in 2010, but they were present in 2.5% and 4.5% in 2014 and 2015, respectively. In 2015, two isolates showed candidate K13 resistance mutations (P574L and A675V), which are common in southeast Asia and associated with delayed parasite clearance. Tacoli C, Gai PP1, Bayingana C, Sifft K, Geus D, Ndoli J, Sendegeya A, Gahutu JB, Mockenhaupt FP. Artemisinin Resistance-Associated K13 Polymorphisms of Plasmodium falciparum in Southern Rwanda, 2010-2015. Am J Trop Med Hyg. 2016 Aug 29. pii: 16-0483 In Mali K13-propeller mutations were identified in both recent samples and pre-ACT infections. Ouattara A, Kone A, Adams M, Fofana B, Maiga AW, Hampton, Coulibaly D, Thera MA, Diallo N, Dara A, Sagara I, Gil JP, Bjorkman A, Takala-Harrison, Doumbo OK, Plowe CV, Djimde AA. Polymorphisms in the K13-propeller gene in artemisinin-susceptible Plasmodium falciparum parasites from Bougoula-Hameau and Bandiagara, Mali. Am J Trop Med Hyg. 2015 Jun;92(6):1202-6. doi: 10.4269/ajtmh.14-0605. Epub 2015 Apr 27. Souleymane Dama, Hamidou Niangaly, Amed Ouattara, Issaka Sagara, Sekou Sissoko, Reduced ex vivo susceptibility of Plasmodium falciparum after oral artemether–lumefantrine treatment in Mali. Malaria Journal201716:59. DOI: 10.1186/s12936-017-1700-8© The Author(s) 2017 At the border between Mali and Mauritania Mohamed Salem Ould Ahmedou Salem, Khadijetou Mint Lekweiry, Houssem Bouchiba, Aurelie Pascual, Bruno Pradines, Ali Ould Mohamed Salem Boukhary, Sébastien Briolant, Leonardo K. Basco and Hervé Bogreau. Characterization of Plasmodium falciparum genes associated with drug resistance in Hodh Elgharbi, a malaria hotspot near Malian–Mauritanian border. Malaria Journal201716:140 DOI: 10.1186/s12936-017-1791-2© In Uganda an independent selection was identified of three polymorphisms in the pfmdr1 gene following administration of AL in a region of Africa where malaria is highly endemic. These polymorphisms were not associated with clinical treatment failure but are evidence for the ability of this drug combination to drive selection of parasites toward resistant phenotypes Christian Dokomajilar, Samuel L. Nsobya, Bryan Greenhouse, Philip J. Rosenthal, and Grant Dorsey Selection of Plasmodium falciparum pfmdr1 Alleles following Therapy with Artemether-Lumefantrine in an Area of Uganda where Malaria Is Highly Endemic. Antimicrob Agents Chemother. 2006 May; 50(5): 1893–1895. doi: 10.1128/AAC.50.5.1893-1895.2006 Stephen Tukwasibwe, Patrick Tumwebaze, Melissa Conrad, Emmanuel Arinaitwe, Moses R. Kamya, Grant Dorsey, Samuel L. Nsobya, Bryan Greenhouse. Drug resistance mediating Plasmodium falciparum polymorphisms and clinical presentations of parasitaemic children in Uganda. Malaria Journal 201716:125. DOI: 10.1186/s12936-017-1777-0 In Tanzania the overall prevalence of NFD haplotype claimed to be associated with emerging artemether-lumefantrine tolerance ranges from 17 to 26% among other haplotypes. With continuation of ALu as first-line drug and in the absence of CQ and AQ, this haplotype is expected to keep rising. There is need for continued pharmacovigilance studies in order to predict early parasite tolerance to the drug Reginald A Kavishe, Petro Paulo, Robert D Kaaya, Akili Kalinga, Marco van Zwetselaar, Jaffu Chilongola, Cally Roper and Michael Alifrangis Surveillance of artemether-lumefantrine associated Plasmodium falciparum multidrug resistance protein-1 gene polymorphisms in Tanzania. Malaria Journal 201413:264 DOI: 10.1186/1475-2875-13-264 In Tanzania the temporal selection of molecular markers associated with artemether-lumefantrine tolerance/resistance may represent an early warning sign of impaired future drug efficacy. This calls for stringent surveillance of artemether-lumefantrine efficacy and emphasizes the importance of molecular surveillance as a complement to standard in vivo trials. Maja Malmberg, Billy Ngasala, Pedro E Ferreira, Erik Larsson, Irina Jovel, Angelica Hjalmarsson, Max Petzold, Zul Premji, José P Gil, Anders Björkman and Andreas Mårtensson. Temporal trends of molecular markers associated with artemether-lumefantrine tolerance/resistance in Bagamoyo district, Tanzania Malaria Journal 201312:103 DOI: 10.1186/1.475-2875-12-103 In Tanzania the difference between individual treatment groups and the next best treatment combination was significant (p<0.001) in every case. Recrudescence rates by day 28, after correction by genotyping, were 48.4%, 34.5%, 11.2%, and 2.8%, respectively. The study shows how few the options are for treating malaria where there is already a high level of resistance to sulfadoxine-pyrimethamine and amodiaquine. Mutabingwa TK, Anthony D, Heller A, Hallett R, Ahmed J, Drakeley C, Greenwood BM, Whitty CJ. Amodiaquine alone, amodiaquine+sulfadoxine-pyrimethamine, amodiaquine+artesunate, and artemether-lumefantrine for outpatient treatment of malaria in Tanzanian children: a four-arm randomised effectiveness trial. Lancet. 2005 Apr 23-29;365(9469):1474-80. In Tanzania a study suggested that drug pressure selection for increased parasite virulence and infectiousness may be occuring in human populations in Africa. BJ Huho, GF Killeen, A Kihonda. Failure of ACTs to suppress human inectiousness in a malaria holo-endemic area, Rufiji-Tanzania, MIM 16757928, MIM conference Nairobi Nov 2009. Kefas Mugittu, Blaise Genton, HP Beck, Molecular monitoring of Plasmodium falciparum resistance to artemisinin in Tanzania. Malaria Journal, 2006, 5 :126 In Senegal parasite drug responses changed between 2008 and 2011, as parasites became less sensitive to amodiaquine, artemisinin and chloroquine over time. The prevalence of known resistance-associated mutations also changed over time. Decreased amodiaquine sensitivity was associated with sustained, highly prevalent mutations in pfcrt, and one mutation in pfmdr1 – Y184F – was associated with decreased parasite sensitivity to artemisinin. Daria Van Tyne, Baba Dieye, Clarissa Valim, Rachel F Daniels, Papa Diogoye Sène, Amanda K Lukens, Mouhamadou Ndiaye, Amy K Bei, Yaye Die Ndiaye, and Daouda Ndiaye. Changes in drug sensitivity and anti-malarial drug resistance mutations over time among Plasmodium falciparum parasites in Senegal. Malaria Journal201312:441 DOI: 10.1186/1475-2875-12-441 In Sierra Leone resistance was already noticed 15 years ago. F Sahr, MJ Bockarie, Apparent drug failure following artesunate treatment of Plasmodium falciparum in Freetown : four case reports. Annals Tropic Med and Parasitol 2001, 95,5 445-449 F Grandesso, A Hagerman, S Kamara, JP Guthman. Low efficacy of artesunate amodiaquine for uncomplicated faciparum malaria among children under 5 years in Kailahun, Sierra Leone, Trop Med and Internat Health, 2004, ISSN 1360-2276 In Uganda Plasmodium genotypes with decreased sensitivity to artemether-lumefantrine increased from 2008 to 2012 in a study involving 312 children Conrad M, LeClair N, Arinaitwe E, Wanzira H, Kakuru A, Bigira V, Muhindo M, Kamya MR, Tappero JW, Greenhouse B, Dorsey G, Rosenthal PJ. Comparative impacts over 5 years of artemisinin-based combination therapies on Plasmodium falciparum polymorphisms that modulate drug sensitivity in Ugandan children. Journal of Infectious Diseases 2014. In press. PMID: 24610872 In Madagascar the results of a study showed the progressive loss of the most susceptible isolates to artemisinin derivatives Valérie Andriantsoanirina, Arsène Ratsimbasoa, Christiane Bouchier, Martial Jahevitra, Stéphane Rabearimanana, Rogelin Radrianjafy, Voahangy Andrianaranjaka, Tantely Randriantso. Plasmodium falciparum Drug Resistance in Madagascar: Facing the Spread of Unusual pfdhfr and pfmdr-1 Haplotypes and the Decrease of Dihydroartemisinin Susceptibility. Antimicrob. Agents Chemother. November 2009 vol. 53 no. 11 4588-4597 doi: 10.1128/AAC.00610-09 In Nigeria a study reveals a need to re-evaluate the quality and efficacy of artemisinin-based combination therapy agents in Nigeria and Sub-Saharan Africa. Though six ACT combination therapies are available, but malaria is resistant to one of the longer-acting drugs and patients had bad reactions to another, so only four ACTs are recommended. Christian Happi, a malaria researchers of Redeemer's University in Lagos declares that among thousands of blood samples anlyzed 80–90% have at least one mutation. Ajayi NA, Ukwaja KN. Possible artemisinin-based combination therapy-resistant malaria in Nigeria: a report of three cases. Rev Soc Bras Med Trop. 2013 Jul-Aug;46(4):525-7. doi: 10.1590/0037-8682-0098-2013. A traveler returning from Nigeria to Canada suffered severe malaria after taking artesunate prophylactically. D Shabinas, Rachel Leu, DR Pillai. Artesunate misuse and Plasmodium falciparum malaria in traveler returning from Africa.Emerging Infectuous Diseases, 2010, 16,10, 1608-1610 In Kenya authors conclude that parasite clearance time after artemisinin-based combination therapy (ACT) may be increasing in Asian and African settings. Beshir KB, Sutherland CJ, Sawa P, Drakeley CJ, Okell L, Mweresa CK, Omar SA, Shekalaghe SA, Kaur H, Ndaro A, Chilongola J, Schallig HD, Sauerwein RW, Hallett RL, Bousema T Residual Plasmodium falciparum parasitemia in Kenyan children after artemisinin-combination therapy is associated with increased transmission to mosquitoes and parasite recurrence. J Infect Dis. 2013 Dec 15;208(12):2017-24. doi: 10.1093/infdis/jit431.. On the Kenyan coast the significant, albeit small, decline through time of parasitological response rates to treatment with ACTs may be due to the emergence of parasites with reduced drug sensitivity, Steffen Borrmann Philip Sasi, Leah Mwai, Declining Responsiveness of Plasmodium falciparum Infections to Artemisinin-Based Elizabeth Juma,Combination Treatments on the Kenyan Coast. PLOS : November 10, 2011 doi.org/10.1371/journal.pone.0026005. In Kenya the findings of another research team call for close monitoring of parasite genotypic, phenotypic and clinical dynamics in response to current first-line treatment in western Kenya. Having been the first focus of chloroquine resistance in Africa western Kenya will be crucial in informing the next steps on the deployment of first-line treatment of uncomplicated malaria in the possible future era of attenuated response of artemisinin. Angela O. Achieng, Peninah Muiruri, Luicer A. Ingasia, Benjamin H. Opot. Temporal trends in prevalence of Plasmodium falciparum molecular markers selected for by artemether–lumefantrine treatment in pre-ACT and post-ACT parasites in western Kenya. Int J Parasitol Drugs Drug Resist. 2015 Dec; 5(3): 92–99. doi: 10.1016/j.ijpddr.2015.05.005 In Senegal the increased prevalence of Pfmdr1 duplication in P. falciparum isolates from patients in Dakar within a 2-year period is cause for concern and vigilance Aurélie Pascual, Bécaye Fall, Nathalie Wurtz, Mansour Fall, Cheikhou Camara,. Plasmodium falciparum with Multidrug Resistance 1 Gene Duplications, Senegal. Emerg Infect Dis. 2013 May; 19(5): 814. doi: 10.3201/eid1905.121603 In Sudan it was observed that the continuous use of SP as a partner to artesunate may be the cause of declined AS/P efficacy. Nahla B Gadalla, Tajeldin M Abdallah, Sharanjeet Atwal, Colin J Sutherland and Ishag Adam. Selection of pfdhfr/pfdhps alleles and declining artesunate/sulphadoxine-pyrimethamine efficacy against Plasmodium falciparum eight years after deployment in eastern Sudan. Malaria Journal 201312:255 DOI: 10.1186/1475-2875-12-255 Increased pfmdr1 copy number and sequence polymorphisms in Plasmodium falciparum isolates was also observed from Sudanese malaria patients treated with artemether-lumefantrine. Gadalla NB, Adam I, Elzaki SE, Bashir S, Mukhtar I, Oguike M, Gadalla A, Mansour F, Warhurst D, El-Sayed BB, Sutherland CJ.Increased pfmdr1 copy number and sequence polymorphisms in Plasmodium falciparum isolates from Sudanese malaria patients treated with artemether-lumefantrine. Antimicrob Agents Chemother. 2011 Nov; 55(11):5408-11. doi: 10.1128/AAC.05102-11. In a malaria endemic area in Kenya a K13 propeller sequence analysis of P. falciparum parasites Kenya did not detect the predicted artemisinin-resistant genotypes, but some temporal substitutions were observed Rie Isozumi, Haruki Uemura, Isao Kimata, Yoshio Ichinose, John Logedi, Ahmeddin H. Omar, and Akira Kaneko. Novel Mutations in K13 Propeller Gene of Artemisinin-Resistant Plasmodium falciparum Emerg Infect Dis. 2015 Mar; 21(3): 490–492.doi: 10.3201/eid2103.1408981st Luicer Anne Ingasia, Lorna Chebon, Artemisinin-based combination therapy efficacy in Kisumu, Western Kenya: selection of parasite subpopulations of Plasmodium falciparum with attenuated response to ACTs.Tropical Medicine & International Health 20:18-18 · September 2015 In Burkina Faso clinical trial NCT00808951 shows a higher occurrence of recurrent malaria infections during a 28-day follow up period for artemether-lumefantrine. Already at the MIM 2009 conference at Nairobi it was stated that 3 years after the ACT introduction there are concerns about the decrease level of theses ACTs efficacy. The risk of treatment failure was already 29,2 % for artemether-lumefantrine. I Zongo, N Rouamba, F Somé, First line therapies of uncomplicated falciparum malaria in Burkina Faso. MIM 16689555 Nairobi 2009. In Gabon severe artemisin resistance was noticed JB Lekana-Douki. High prevalence of markers associated with failure treatments of artemisinin based combination therapy in urban Gabonese regions. 6th MIM Conference 2013 P379 In Gabon another study confirms these intriguing results. The strongest correlation between diminished DHA sensitivity and MF resistance was observed, followed by correlation between diminished DHA sensitivity and CQ resistance. Cross-resistance between CQ and MF was also observed. Zatra R, Lekana-douki JB, Lekoulou F, Bisvigou U, Ngoungou EB, Ndouo FS. In vitro antimalarial susceptibility and molecular markers of drug resistance in Franceville, Gabon. BMC Infect Dis. 2012 Nov 15;12:307. doi: 10.1186/1471-2334-12-307. In Surinam an increase in the rate of day 3 parasitaemia was observed from 2-31% over a five-year time span. Our study supports the use of day 3 parasitaemia as a tool for screening artemisinin resistance, particularly in the absence of functional molecular markers and standardised in vitro test systems. The WHO advises that an incidence of day 3 parasitaemia that exceeds 10% should prompt governments to take measures to prevent the development of treatment failure Stephen GS Vreden Jeetendra K Jitan, Rakesh D Bansie, and Malti R Adhin. Evidence of an increased incidence of day 3 parasitaemia in Suriname: an indicator of the emerging resistance of Plasmodium falciparum to artemether Mem Inst Oswaldo Cruz. 2013 Dec; 108(8): 968–973. doi: 10.1590/0074-0276130167 In Mozambique, after the decrease in clinical malaria incidence observed until 2009, a steady resurgence of cases per year has been reported nationally, reaching alarming levels in 2014. Beatriz Galatas, Caterina Guinovart, Quique Bassat, John J. Aponte, Lídia Nhamússua, Eusebio Macete, Francisco Saúte, Pedro Alonso and Pedro Aide. A prospective cohort study to assess the micro-epidemiology of Plasmodium falciparum clinical malaria in Ilha Josina Machel (Manhiça, Mozambique). Malaria Journal201615:444 DOI: 10.1186/s12936-016-1496-y In Ethiopia high rates of recurrent parasitemia were noted for AL and CQ against Plasmodium vivax J Hwang, BH Alemayehu, R Reithinger, H Nettey, T Teshi. Vivo Efficacy of Artemether-Lumefantrine and Chloroquine against Plasmodium vivax: A Randomized Open Label Trial in Central Ethiopia. May 22, 2013 .doi.org/10.1371/journal.pone.0063433 In Ghana the persistent detection of low density Plasmodium sp. Infections, following antimalarial treatment suggests these may be a hitherto unrecognised obstacle to malaria elimination Dinko B, Oguike MC, Larbi JA2, Bousema T, Sutherland CJ. Persistent detection of Plasmodium falciparum, P. malariae, P. ovale curtisi and P. ovale wallikeri after ACT treatment of asymptomatic Ghanaian school-children. Int J Parasitol Drugs Drug Resist. 2013 Jan 19;3:45-50. doi: 10.1016/j.ijpddr.2013.01.001. In Liberia it was found that although treatment is highly efficacious, selection of molecular markers in reinfections could indicate a decreased sensitivity or tolerance of parasites to the current treatments and the baseline prevalence of molecular markers should be closely monitored S Otienoburu, O Maïga-Ascofaré, B Schramm, Vincent Jullien, JJones, Yah M. Zolia, Pascal Houzé, , J Le Bras and S HouzéSelection of Plasmodium falciparum pfcrt and pfmdr1 polymorphisms after treatment with artesunate–amodiaquine fixed dose combination or artemether–lumefantrine in Liberia. Malaria Journal 201615:452 DOI: 10.1186/s12936-016-1503- In Kivu, RDC, the high reinfection rate after Coartem and ASAQ treatment raises concerns and requires further studies. M de Wit, Anna L. Funk, K Moussally, DNkuba, RSiddiqui, Karla Bil, E Piriou, P Bousema. In vivo efficacy of artesunate–amodiaquine and artemether–lumefantrine for the treatment of uncomplicated falciparum malaria: an open-randomized, non-inferiority clinical trial in South Kivu, Democratic Republic of Congo. Malaria Journal201615:455 DOI: 10.1186/s12936-016-1444- A recent paper from RDCongo found 5 resistance genes related to ACT tratment. Mvumbi Dieudonné · Jean-Marie Kayembe · Hippolyte Situakibanza ·· Marie-Pierre Hayette, Falciparum malaria molecular drug resistance in the Democratic Republic of Congo: A systematic review· Sep 2015 · Malaria Journal In Sudan the findings of a study call for a need to review the Sudan malaria treatment policy. Epidemiological factors could play a major role in the emergence of drug-resistant malaria in eastern Sudan. A A. Adeel, F Elnour, K Elmardi, Abd-Elmajid, M Elhelo. High efficacy of artemether-lumefantrine and declining efficacy of artesunate + sulfadoxine-pyrimethamine against Plasmodium falciparum in Sudan (2010–2015): evidence from in vivo and molecular marker studies. Malaria Journal 201615:285 DOI: 10.1186/s12936-016-1339-x In Angola resistance to lumefantrine and artemisinine derivatives was extensively studied. Cláudia Fançon, Miguel Brito and Jose Pedro Gil. Plasmodium falciparum drug resistance in Angola. Malaria Journal 201615:74 DOI: 10.1186/s12936-016-1122-z The most recent paper confirming resistance to ACTs comes from China and concerns a traveller returning home from Equatorial Guinea with malaria in 2012. It took thus 5 years to get this case published. Juan Cao, Richard Culleton, Didier Menard. Emergence of Indigenous artemisinin-resistant Plasmodium falciparum in Africa. NEJM 2017 February 22 The same information is repeated by other authors. A taboo is definitely broken. Feng Lu, R Culleton, M Zhang, A Ramaprasad, L von Seidlein. Emergence of Indigenous Artemisinin Resistant Plasmodium falciparum in Africa, NEJM Mar 9 2017, 376 ;10