Growing concerns for malaria resistance to Artemisinin

A new study has found three new strains of malaria in Cambodia that are resistant to the drug Artemisinin (Miotto et al., 2013), which is widely used as a first-line treatment for malaria in artemesinin-based combination therapies such as Coartem, and one of the most effective drugs available.
Clinical evidence for artemesinin resistance was first reported in the region in 2008 (Noedl et al., 2008), and these findings are considered a major threat to global malaria control, particularly in Africa, where 90% of all malaria deaths occur. While no study has yet confirmed the presence of artemisinin resistance in Africa, all the early warning signs are present. In this month’s Malaria Journal, a new study shows an increase in the prevalence of genes associated with artemether-lumefantrine (Coartem) resistance in malaria parasites in Tanzania (Malmberg et al., 2013).  Similar observations have been reported in several other African countries since the widespread use of Coartem, including Gabon, Kenya and Mozambique. The Gabon study, published by our CIRMF colleagues in 2011, reported an increase in the prevalence of a Coartem-resistant genotype in P. falciparum parasites in Franceville (Lekana-Douki et al., 2011).

These findings are cause for particular concern for Gabon, where malaria is the prime cause of death and reportedly on the increase. Studies indicate that at the time the government was actively running a national malaria control program that involved the distribution of mosquito nets, infection rates were decreasing across the country (Mourou et al., 2012; Bouyou-Akotet et al., 2009). However, more recently, malaria prevalence appears to be on the increase (Mawili-Mboumba et al., 2013).

The national parks have lost several colleagues to malaria in recent years. It is becoming increasingly important that effective malaria awareness strategies are put in place, and more efforts are made to improve malaria prevention and response. 

Bouyou-Akotet MK, Mawili-Mboumba DP, Kendjo E, Mabika-Mamfoumbi M, Brice Ngoungou E, Dzeing-Ella A, Pemba-Mihindou M, Ibinga E, Efame-Eya E, MCRU team, Planche T, Kremsner PG, M K, 2009. Evidence of decline of malaria in the general hospital of Libreville, Gabon from 2000 to 2008. Malaria Journal 8:300.

Lekana-Douki JB, Dinzouna Boutamba SD, Zatra R, Zang Edou SE, Ekomy H, Bisvigou U, FS: T-N, 2011. Increased prevalence of the Plasmodium falciparum Pfmdr1 86N genotype among field isolates from Franceville, Gabon after replacement of chloroquine by artemether-lumefantrine and artesunate-mefloquine. Infect Genet Evol 11:512-517.

Malmberg M, Ngasala B, Ferreira P, Larsson E, Jovel I, Hjalmarsson A, Petzold M, Premji Z, Gil JP, A B, A M, 2013. Temporal trends of molecular markers associated with artemether-lumefantrine tolerance/resistance in Bagamoyo district, Tanzania. Malaria Journal 12:1-7.

Mawili-Mboumba DP, Akotet MKB, Kendjo E, Nzamba J, Medang MO, Mbina J-RM, Kombila M, 2013. Increase in malaria prevalence and age of at risk population in different areas of Gabon. Malaria Journal 12.

Miotto O, Almagro-Garcia J, Manske M, MacInnis B, Campino S, Rockett KA, Amaratunga C, Lim P, Suon S, Sreng S, Anderson JM, Duong S, Nguon C, Chuor CM, Saunders D, Se Y, Lon C, Fukuda MM, Amenga-Etego L, Hodgson AVO, Asoala V, Imwong M, Takala-Harrison S, Nosten F, Su X-z, Ringwald P, Ariey F, Dolecek C, Hien TT, Boni MF, Thai CQ, Amambua-Ngwa A, Conway DJ, Djimde AA, Doumbo OK, Zongo I, Ouedraogo J-B, Alcock D, Drury E, Auburn S, Koch O, Sanders M, Hubbart C, Maslen G, Ruano-Rubio V, Jyothi D, Miles A, O'Brien J, Gamble C, Oyola SO, Rayner JC, Newbold CI, Berriman M, Spencer CCA, McVean G, Day NP, White NJ, Bethell D, Dondorp AM, Plowe CV, Fairhurst RM, Kwiatkowski DP, 2013. Multiple populations of artemisinin-resistant Plasmodium falciparum in Cambodia. Nat Genet advance online publication.

Noedl H, Se Y, Schaecher K, Smith BL, Socheat D, Fukuda MM (2008). Evidence of artemisinin-resistant malaria in western Cambodia. N. Engl. J. Med. 359 (24): 2619–20.