Travelers are not protected against malaria by ACTs

ACT resistance in travelers Not only residents in Africa are affected by ACT resistance. Also travelers returning from malaria endemic areas suffer are victims of the same failures. A retrospective comparative analysis of treatment regimen for P. falciparum malaria in adults in Stockholm during 2000-2015 was performed to evaluate the effectiveness of artemether-lumefantrine. Parasite genotyping and drug concentrations were investigated in the AL treatment failures. AL failures occurred in European men and the effectiveness in this group was only 73.7% (95% CI, 48.8%-90.0%). Genotyping confirmed recrudescence of the initial parasite populations and drug resistance markers revealed no clinically significant resistance patterns. Lumefantrine concentrations suggested subtherapeutic concentrations in at least 2 cases. These findings indicate a high rate of symptomatic late treatment failures after 6-dose AL regime in nonimmune adults, especially in men. The report warrants the need to alert clinicians about the importance of informing patients regarding the risk of parasites reappearing weeks after AL treatment. Sondén K, Wyss K, High Rate of Treatment Failures in Nonimmune Travelers Treated With Artemether-Lumefantrine for Uncomplicated Plasmodium falciparum Malaria in Sweden: Retrospective Comparative Analysis of Effectiveness and Case Series. Clin Infect Dis. 2017 Jan 15;64(2):199-206. doi: 10.1093/cid/ciw710. Four British citizens who caught malaria while travelling in Africa have shown apparent resistance to the main drug used to treat the disease, according to researchers at the London School of Hygiene and Tropical Medicine. Scientists say the discovery should act as a warning for Africa, where the drug has played a key role in sharply reducing mortality rates from malaria. The four travelers were treated with a drug called Artemether-Lumefantrine after returning to Britain from different parts of Africa within a five-month period, showing symptoms of malaria. The cases alerted scientists at the London School of Hygiene and Tropical Medicine Sutherland CJ, Lansdell. P3pfk13-Independent Treatment Failure in Four Imported Cases of Plasmodium falciparum Malaria treated with Artemether-Lumefantrine in the United Kingdom. Antimicrob Agents Chemother. 2017 Feb 23;61(3). pii: e02382-16. doi: 10.1128/AAC.02382-16. Tunesia reports a case of possible clinical failure of artemether-lumefantrine treatment in a 26-year old Tunisian traveler with uncomplicated P. falciparum malaria imported from Cote d’Ivoire Aouam A, Toumi A, Ikbel K, Brahim HB, Loussaief C, et al. Artemether–Lumefantrine Treatment Failure in a Falciparum Malaria Patient in Tunisia. J Neurol Transl Neurosci. 2016. 4(1): 1060 Another study reports the case of three, non-immune, expatriate workers with P. falciparum acquired in Africa, who failed to respond to artemisinin-based therapy. Yves Jackson, François Chappuis, Louis Loutan, and Walter Taylor. Malaria treatment failures after artemisinin-based therapy in three expatriates: could improved manufacturer information help to decrease the risk of treatment failure? Malar J. 2006; 5: 81. Neumayr A, Paris DH, Genton B, Hatz C. Artemether-Lumefantrine Treatment Failure in Nonimmune European Travelers with Plasmodium falciparum Malaria: Do We Need to Reconsider Dosing in Patients from Nonendemic Regions? Clin Infect Dis. 2017 May 15;64(10):1466-1467