Open access peer-reviewed chapter

The Artemisinin Resistance in Southeast Asia: An Imminent Global Threat to Malaria Elimination

Written By

Aung Pyae Phyo and François Nosten

Submitted: 13 June 2017 Reviewed: 15 March 2018 Published: 18 July 2018

DOI: 10.5772/intechopen.76519

From the Edited Volume

Towards Malaria Elimination - A Leap Forward

Edited by Sylvie Manguin and Vas Dev

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Malaria remains a leading cause of mortality and morbidity in many low- and middle-income countries. Artemisinin combination therapies (ACTs) have contributed to the substantial decline in the worldwide malaria burden, renewing the optimism that malaria elimination is achievable in some regions of the world. However, this prospect is threatened by the emergence of artemisinin resistance in Plasmodium falciparum leading to clinical failure of ACTs in Southeast Asia. Historically, drug resistance in P. falciparum has emerged in SEA and spread to Africa. Today, resistance to ACTs could reverse all the achievements of control and elimination efforts globally. With no new drug available, P. falciparum malaria must be eliminated from the Greater Mekong before it becomes untreatable.


  • falciparum malaria
  • artemisinin
  • ACT
  • resistance
  • malaria elimination
  • Southeast Asia

1. Introduction

The emergence of artemisinin-resistant falciparum malaria along the Thai-Cambodian border follows a familiar pattern. History shows that chloroquine resistance had arisen from this region in the 1950s (Table 1) and leads to the failure of the Global Malaria Eradication Programme [1, 2] Resistance to artemisinin with concomitant emergence of partner drug resistance is now causing high artemisinin combination therapy (ACT) treatment failure rates in Cambodia, Vietnam, Thailand, Laos and Myanmar (Table 1). The prospect of untreatable malaria has once again loomed and threatened the effective malaria control and elimination efforts.

Antimalarial drug Year of first deployment Place of first deployment Year of resistance emerged Place of emergence of resistance
Quinine 1630 [34] South America [34] 1910* Brazil [28, 29]
Chloroquine 1945 Global Malaria Eradication Campaign [127] 1957 Colombia, Cambodia-Thailand border [41, 128, 129, 130]
Amodiaquine 1948 Americas
[131, 132]
1961 Colombia [56, 57]
Atovaquone 1996 Thailand [73] 1996 Thailand [72, 73, 75]
Proguanil 1948 Various African countries [133] 1949 Aden Protectorate, Yemen [134]
Sulfa + antifols° 1967 Thailand [135] 1967 Thailand [135]
Mefloquine 1967 Vietnam [136] 1982 Thailand [7, 8, 43]
Piperaquine 1978 China [137] 1985 China [138]
Artemisinin 1979 China [139] 2008 Cambodia [6]
Mefloquine-artesunate 1994 Thailand [140] 2002α Cambodia [141]
Artemether-lumefantrine 1994 China [142] 2006α Cambodia [143, 144]
Dihydroartemisinin-piperaquine 2001 Cambodia [145] 2013α Cambodia [86, 146, 147]

Table 1.

Different antimalarial drugs and years/places of deployment and emergence of resistance [references in bracket].

There is no high-grade resistance to quinine.

Therapeutic efficacy <90% (cut-off threshold of WHO to switch the ACT policy).

Sulfa + antifols: Sulfadoxine + antifolates.


2. Background

Resistance in Plasmodium falciparum has already developed to all antimalarial drug classes deployed for treatment. Paradoxically, the number of antimalarials available or in development has remained small. For most of the twentieth century, chloroquine was the main drug used to treat or prevent malaria. The discovery of chloroquine after World War II, and the widespread use of DDT for vector control, had triggered hope that malaria eradication was possible [3]. Unfortunately, chloroquine resistance did emerge and spread to the African continent within two decades annihilating the prospect of malaria eradication [4]. Although several countries did achieve malaria elimination (in Europe and the Americas), others saw a dramatic resurgence of the disease [3]. Over the following period, P. falciparum developed resistance to all antimalarial drugs, including sulfadoxine, pyrimethamine, mefloquine, atovaquone, artemisinin derivatives and piperaquine [5, 6, 7, 8]. The most accurate and up-to-date data repository of the clinical trials on the efficacy of antimalarials, and the temporal and geographical spread of resistance is accessible at the Worldwide Antimalarial Resistance Network (WWARN:

In 2007, the Bill and Melinda Gates Foundation announced that it was investing millions of dollars to revitalise the efforts of malaria elimination [9]. Ten years later, this seems to be an achievable goal since the global malaria burden has diminished (Figure 1), an encouraging result attributed to the widespread deployment of long-lasting impregnated nets (LLINs), the ACTs and increased availability of malaria diagnostic tests [10]. However, the failure of the ACTs, the extension of vector resistance to the insecticides and the recent increase in the number of malaria cases are clear reminders that malaria is a formidable foe. Without new strategies, the same causes will lead to the same consequences [10] .

Figure 1.

World atlas showing the countries with different stages of malaria endemicity [10] and status of drug resistance [121]. Right side: Prevalence (small pin: <10%, medium pin: 10–50%, large pin: >50% prevalence) of Pfmdr-1 CNV [25, 122], Plasmepsin 2–3 CNV [26, 87], K-13 mutation [101, 123, 124] and possible spread [125, 126].


3. Mechanisms and emergence of antimalarial drug resistance

Causal stimuli of antimalarial resistance consist of spontaneous mutations in the parasite genome, antimalarial pharmacokinetics and the magnitude of parasite gene pool, which is proportionate to transmission intensity.

Primarily, as an innate survival strategy of microorganisms, mutation(s) occur de novo, independent of drug pressure. However, the parasite’s genome replication rate, mutation rate per base-pair per parasite generation and the total number of parasites at any given time are the principal determinants in spontaneous mutation [11, 12]. These spontaneous mutations can be either minor scale modification, such as insertion, deletion or variation in a nucleotide (frame-shift mutation or single-nucleotide polymorphism), or bulky transfiguration of large chromosomal regions (gene amplification/deletion/copy number variations). For some drugs, a single genetic event may be all that is required. A single point mutation in the parasite genome is sufficient to confer resistance (e.g. atovaquone), while for other drugs, multiple unlinked events (epistatic modulation) may be necessary (e.g. triple mutant in pyrimethamine [13, 14], Kelch-10, Kelch-13 and background mutations [15, 16, 17] in artemisinin resistance).

Spontaneous mutations, in the particular genes encoding the drug target, cause the reduction in drug accumulation or efflux (chloroquine, amodiaquine, quinine, mefloquine, halofantrine resistance) or reduced affinity of the drug target (pyrimethamine, cycloguanil, sulphonamide, atovaquone resistance), which finally enables the parasite to withstand the antimalarial treatment. Afterwards, the drug pressure facilitates the resistant parasites to propagate by eliminating the susceptible parasites, which are usually more fit and would outcompete the resistant ones in the absence of the drug. Eventually resistance becomes established and can persist or be reintroduced. In the absence of drug pressure, the resistant parasites have no longer any survival advantage and can be overtaken by wild-type (sensitive) parasites [18, 19]. But as soon as the abandoned drug is reintroduced, the resistant isolates regain their survival advantage and expand rendering the drug inefficient within a short time [20].

Large-scale and/or long-term distribution of several tons of medicated salt took place in many countries and was an important factor implicated in the emergence of both chloroquine and sulfadoxine/pyrimethamine (SP) resistance and accelerating their spread [21, 22, 23]. In WHO supported programs, the doses of antimalarial received by each individual were highly variable, and constant exposure to sub-parasiticidal (or even parasiticidal) drug concentrations might have eliminated the highly and moderately sensitive parasites, providing a selective advantage for less sensitive counterparts. Thus, the speed of selection of mutant parasites depends principally on the pharmacokinetics of the drug (slowly eliminated drugs with a long tail of sub-parasiticidal concentrations generally select faster) and the magnitude of drug use within a population (the higher the drug pressure per parasite, the faster the selection).

With ACTs, the newly emerged drug-resistant parasite has to overcome the parasiticidal action of the partner drug as well as the host immunity. At this point, with compromised efficacy of partner drug, along with declining immunity of the population, resistance to ACT combination is inevitable [24]. This is the reason why artemisinin resistance has led to the clinical failure of mefloquine-artesunate and DHA-piperaquine combinations [25, 26].

The reason why antimalarial resistance always emerged in the same region of the world (SEA and specifically in Western Cambodia) is currently unknown. Some contributing factors have been proposed such as the low level of acquired immunity, the weak and seasonal transmission, the availability of antimalarial drugs, usage of monotherapies, sub-standard or counterfeit drugs, porous borders. The answer will probably be given by studies of the parasite population genetics, and recent work has shown the existence of “founding populations” favourable to the emergence of resistant parasites [17].

The emergence of drug resistance to various antimalarial compounds is mentioned by chronology in Table 1 (antimalarial drugs and years/places of deployment and emergence of resistance).

3.1. Quinine resistance

Quinine, initially as cinchona bark, was first used as a fever medicine and officially introduced into the London Pharmacopoeia in 1677 [27]. The earliest resistance to quinine was reported in 1910 [28, 29]. Like chloroquine, quinine has been shown to accumulate in the parasite’s digestive vacuole inhibiting the haem detoxification process. Quinine resistance also seems to be associated with reduced drug uptake by the parasite. There is a weak association between quinine resistance and Pfmdr-1 amplification or Pfmdr-1 SNP as well as Pf Na-H exchanger (Pfnhe-1) and Pfcrt [30, 31]; hence, it is probable that multiple genes are influencing susceptibility and probably in a strain-dependent manner. There were only a few in vitro data in Asia [32], South America [33] and Africa [34] showing diverse range of sensitivities. However, the review paper of over 400 clinical trials showed that the failure rates for quinine (the only compound besides artemisinins, derived from nature) reported over the past 30 years remain steady and high grade clinical resistance to quinine is very rare [35].

3.2. Chloroquine resistance

Chloroquine, considered as one of the most successful medications ever deployed, saving several millions of lives, was developed in 1934 [2, 36] and replaced quinine for shorter regimen with better adherence. Single nucleotide polymorphisms in Pfcrt gene encoding for a transporter, chloroquine (CHQ) resistance transporter in the food vacuole causing the efflux of CHQ [37, 38], and acidification of the food vacuole [39] are significantly associated to CHQ resistance in vitro and are sensitive markers for therapeutic failure. Phylogenetic analysis revealed that a single lineage of CHQ-resistant Pfcrt alleles, that is, CVIET/S (K76T and mutations in three other amino acids, at positions 72, 74, 75 and 76) [40], which had emerged on the Thai-Cambodia border in 1957 [41], spread to India and Middle East countries between 1977 and 1987, reached West Africa in 1987 and propagated throughout the African continent leading to the death of millions of children [2, 38, 42, 43].

3.3. Antifolate resistance

After the emergence of chloroquine resistance, sulfadoxine-pyrimethamine (SP) combination was deployed by the Thai Malaria Control Program as the first-line regimen for falciparum malaria in 1973. Afterwards, SP was extensively used throughout the country and was also available as an over-the-counter fever remedy in local dispensaries. Attributed to a number of reasons, including unrestricted usage, distribution of pyrimethamine medicated salt [23], superfluous drug pressure (prophylactic as well as presumptive use for fever) and poor compliance especially in migrant mobile population, the resistance to SP combination had emerged around 1980 in the Thai-Cambodian border [5, 44]. Then, in the early 1980s, even with an increased dose (i.e. three tablets of SP, instead of two tablets flat dosing), a cure rate of only 30–40% was achieved [44].

Point mutations at codons 51, 59, 108 and 164 in the dhfr gene [45, 46] confer resistance to pyrimethamine; double or triple mutant resistant strains generated from sequential point mutations, based upon the common S108 N allele, are associated with 100-fold rise of in vitro sensitivity to pyrimethamine compared to wild-type [47]. Similarly, sulfadoxine resistance is associated with DHPS mutations at codons 436, 437, 581, 613 and 540 [48, 49]. Pyrimethamine resistant double mutant alleles (S108 N plus one more mutation at position 51 or 59) with low-level resistance of dhfr have multiple independent origins [50, 51]; by contrast, there were only a few or perhaps a single founding mutant lineage for the triple (N51I + C59R + S108 N) mutant dhfr allele, which originated from Southeast Asia (SEA) and spread to Africa [13, 14].

3.4. Amodiaquine resistance

Amodiaquine is structurally related to chloroquine but these amino-4-quinolines have different resistance patterns. Amodiaquine is effective against chloroquine-resistant isolates. However, parasites carrying the CVIET allele on the Pfcrt gene, as well as 86Y and 1246Y polymorphisms on the Pfmdr-1 gene, are resistant to amodiaquine [52, 53, 54, 55]. The earliest report of resistance was documented since 1961 [56, 57], and widespread resistance to amodiaquine monotherapy was seen in 1980s [58].

3.5. Mefloquine resistance

Mefloquine was first produced in 1969 by the US Army Antimalarial Drug Development Program, primarily for the chemoprophylaxis in the military. The early therapeutic efficacy trial of mefloquine in Thailand showed 100% efficacy in 1976 [59] and in combination with SP where 97% efficacy was proven in a large-scale trial during 1983–1985 [60, 61]. Then, in 1991, mefloquine monotherapy was used as the first line regimen for P. falciparum malaria in Thailand [62]. Even with the stringent regulatory measures in Thailand, the therapeutic efficacy of mefloquine fell hastily especially in the border areas [7, 63]: because of the difficulties in restricting all access to the drug which was available across neighbouring porous borders. Then, in 1992, the cure rate of mefloquine monotherapy had fallen to 49% with 16% of high-grade failures in children [7, 63].

Resistance to mefloquine was proven to be mediated by Pfmdr-1 gene amplification. Pfmdr-1 is the gene encoding a transporter pump, P-glycoprotein homologue 1 (Pgh1), localised at the surface of the digestive vacuole of parasite (Figure 2). It confers drug resistance through both gene copy number variation (CNV) and point mutation (at nucleotide level). Altering the gene copy number provides a modest way to change gene expression without affecting the nucleotide sequence [64]. Increased Pfmdr-1 copy number is a significant independent risk factor for recrudescence in patients treated with mefloquine containing therapy [65, 66, 67] as well as in vitro mefloquine resistance [68]. Pfmdr-1 gene amplification can be selected in vitro by exposing the parasites to stepwise increasing concentrations of mefloquine [69]. Reciprocally, reducing the copy number from isolates with multiple copies resulted in increased in vitro sensitivity of isolates to mefloquine, lumefantrine, halofantrine, quinine and artemisinin due to reduced transcription and encoding of Pgh-1 pump [70]. This is also true for the clinical efficacy since the rise and fall of amplified Pfmdr-1 prevalence is temporally associated with the deployment of mefloquine in Cambodia [65, 71]. Along the Thailand-Myanmar border, patients infected with parasites having both Pfmdr-1 multiple copy number and K-13 mutation were 14 times more likely to get recrudescence compared to the patients infected with wild-type infections [25].

Figure 2.

Pfmdr-1 gene and mechanism of Pgh-1 pump. MFQ – mefloquine, LMF – lumefantrine, CHQ – chloroquine and RBC – red blood cell.

3.6. Atovaquone resistance

Atovaquone was trialled as a monotherapy as well as in combination with proguanil between 1990 and 1996 in Thailand, and the therapeutic efficacy of atovaquone-proguanil was proven to be superior to mefloquine monotherapy, chloroquine, amodiaquine monotherapy and SP [72, 73]. A single point mutation (codon 268 in the cyt-b gene) in the ubiquinol oxidation region of cytochrome b confers atovaquone resistance in vivo [74, 75]. Generally, resistance conferred by a single point mutation can be rapidly acquired both in vivo and in vitro, and once the mutation is acquired, resistance becomes complete. Thus, not very long after deployment, atovaquone-resistant parasites could be selected in vitro after 5 weeks of continuous culture [76, 77]. In addition, atovaquone-resistant parasites were also resistant to the synergistic effects of proguanil [78], suggesting that once atovaquone resistance arises, the atovaquone-proguanil combination (Malarone) will be ineffective since cycloguanil (proguanil) resistance is already established in most malaria endemic areas.

3.7. Pyronaridine resistance

Pyronaridine is a quinoline derivative compound with similar molecular structure as chloroquine and amodiaquine. There was a strong correlation between in vitro sensitivity of pyronaridine and that of amodiaquine and halofantrine [79]. Ex vivo data indicated that there is an association between reduced susceptibility to pyronaridine and K76 T polymorphism in Pfcrt gene. However, there are scanty data on clinical trials and no confirmed report of molecular marker of pyronaridine resistance has been documented. Pyronaridine-artesunate combination had been granted a positive scientific opinion by the European Medicines Agency, removing all restrictions on repeat dosing with a condition to use only in areas of high resistance and low transmission, and has been included in WHO’s list of prequalified medicines [80]. However, day-42 cure rate of <90% in Western Cambodia has challenged the expediency of the pyronaridine-artesunate combination in ACT resistance setting [81].

3.8. Piperaquine resistance

Piperaquine (PPQ) has no cross resistance with chloroquine, and susceptibility is not associated with mutations on the Pfcrt gene [82, 83]. PPQ resistance is inversely correlated with mefloquine resistance in vitro and hence with Pfmdr-1 copy number amplification [84, 85, 86]. Later findings have shown that the amplification of Plasmepsin-2 gene (probably Plasmepsin-3 as well) on chromosome 14 is significantly associated with piperaquine resistance in vitro as well as in vivo [26, 87]. Worryingly, a recent study in Cambodia has demonstrated the presence of parasite isolates with amplification of both Pfmdr-1 and plasmepsin-2 genes [20]. This finding indicates that the parasite has successfully adapted to acquire concomitant mutations related to resistance to these two different antimalarial partner drugs [20].

3.9. Artemisinin resistance

Artemisinins are thought to be inhibitor of P. falciparum phosphatidylinositol-3-kinase (PfPI3K), which phosphorylates phosphatidylinositol to produce phosphatidylinositol 3-phosphate involved in cell survival pathways. Hence, inhibition of PfPI3K activity causes a reduction in PI3P level, which subsequently leads to parasite death. After the introduction of artemisinins in the 1990s, the unanimous opinion by the experts was that resistance was unlikely to emerge because of inherent pharmacokinetic-dynamic property of the molecule. However, artemisinins were not everlasting drugs and the artemisinin resistance did emerge in 2008 [6].

There are two main proposed pathways for artemisinin resistance with the involvement of Kelch (K-13) mutations, that is, a cell survival signalling pathway with PfPI3K and an unfolded protein response pathway (UPR) [88].

In Kelch (propeller) mutant alleles, the mutations may alter the topology of the Kelch protein probably by modification of surface charges that disrupt interactions with other enzymes such as PfPI3K [89]. This leads to a reduced amount of ubiquitination, as well as degradation of PfPI3K associated with increased levels of both the enzyme PfPI3K and the substrate PI3P [90, 91]. The PI3P facilitating the host remodelling is present in the apicoplast and food vacuole and contributes to the cell survival pathways either through redox, transcriptional or DNA repair [90, 91, 92, 93, 94]. All of which have been implicated in artemisinin resistance [90, 95, 96, 97, 98].

Possible mechanisms proposed by transcriptomic study [99] is through upregulation of genes involved in the UPR pathway (especially two putative chaperonin complexes, Plasmodium reactive oxidative stress complex/PROSC and TCP-1 ring complex/TRiC) which enhances the capacity of parasites to quickly repair or degrade proteins or other cellular components. (The UPR pathway is usually damaged by brief artemisinin exposures in patients, but these genes are upregulated in artemisinin resistant parasites) and/or downregulation of genes involved in DNA replication, which is associated with developmental arrest and dormancy [100].

The role of Kelch non-propeller mutation (before the amino acid position 441) is still unclear. Some SNPs like E252Q emerged earlier along the Thai-Myanmar border and associated with reduced efficacy of ACT [25] but are being taken over by the propeller SNPs particularly C580Y [101]. All these findings indicate that artemisinin resistance is likely to be multi-locus and that other genetic changes, such as P623T polymorphism in Kelch-10 gene [15] and background mutations (arps10-apicoplast ribosomal protein S10, Pfmdr-2, ferredoxin, Pfcrt [17], etc.), are providing compensatory fitness for K-13 mutant parasites or perhaps conferring partner drug resistance.


4. Resistance facilitates the transmission potential

For the newly selected resistant parasites to be propagated, the recrudescent infection is essential [102]. The threshold for successful transmission of malaria is around six viable gametocytes in one blood meal [103]. Post-treatment gametocytaemia is a composite of ongoing gametocytogenesis despite treatment (especially with ineffective drug) and the release of sequestered gametocytes, which is enhanced by drug-induced stress [104]. If the malaria infection is treated with partially effective drugs, post-treatment gametocytaemia is more likely. This was clearly shown for drugs such as CHQ and SP [105] as evidenced in patients with slower parasite clearance after artesunate treatment [106]. Moreover, mutant isolates were also related to pre- and post-treatment gametocytaemia [107, 108, 109, 110] and hence possess transmission advantage (Figure 3).

Figure 3.

Postulated flow chart of emergence/spread of drug resistance (copyright permission from Prof Francois Nosten).


5. Prospects of elimination

With the declining transmission of malaria, the geographic clustering of both clinical and asymptomatic infections has become more apparent. Asymptomatic carriers represent a “reservoir” of parasites that are difficult to detect because the density of parasites is often below the sensitivity threshold of conventional diagnostic tools (Rapid Diagnostic Tests and microscopy). The size of these reservoirs of sub-microscopic infections (also called “hot-spots”) can vary from a few households to large geographical areas. Clustering of these hotspots becomes more pronounced as transmission declines [111]. While considering malaria elimination, radical depletion of parasite reservoir (asymptomatic carriers with sub-microscopic parasitaemia) and gametocytes is a necessity. This can be achieved by two functional components: (1) early diagnosis with treatment (EDT) of the symptomatic patients (preferably within 48 hour of symptoms before the development of gametocytaemia) and (2) early detection and treatment targeting the reservoirs of sub-microscopic infections through Mass Drug Administration (MDA) [112, 113].

The intervention for the first element is to set up or reinforce and sustain malaria control program hence reducing the number of clinical episodes as much as possible through increased access to EDT where the use of efficacious antimalarial regimen is critical [114]. As the drug resistance worsen, the rising number of clinical cases due to increasing gametocyte carriage in the community will be inevitable. MDA or mass screening and treatment (MSAT) is only accelerating the malaria elimination alongside EDT, by eliminating the sub-microscopic reservoir [115]. The effectiveness of MDA or MSAT significantly relies on the therapeutic efficacy of the drug in use, the coverage and the total number of rounds of MDA. In turn, this means that a careful and well-conducted community engagement is primordial for enhanced coverage [115, 116].


6. Choice of drug for malaria elimination: is the pipeline empty?

The current malaria elimination program along the Thai-Myanmar border is using artemether-lumefantrine (AL) for treating the clinical cases at the village malaria posts or by malaria workers [114], whereas dihydroartemisinin-piperaquine (DP) is deployed in MDA activities [117]. In this area, the third ACT, mefloquine-artesunate combination, is already failing [25], and the prospect of elimination program is highly dependent on the therapeutic efficacy of AL and DP. Recent emergence of piperaquine resistance following the artemisinin resistance has depleted the available ACTs to be deployed in malaria elimination programs. High failure rates of AL in Laos PDR and DP in Vietnam and Cambodia have cast doubts on the optimism of malaria elimination [10, 26, 87, 118].

There are very few new compounds in the development pipeline. The front runners are OZ439, a synthetic endoperoxide, structurally related to artemisinin, and KAF156 belonging to a new class of antimalarial (imidazolopiperazines) and the spiroindolone cipargamin (formerly KAE609). However, these short-acting drugs will have to be deployed in combination therapies and their full development will take many years.

As a stopgap measure, two triple ACTs (mefloquine plus DP and amodiaquine plus AL) are under multicentre trial, using the inverse correlation between susceptibility to amodiaquine and lumefantrine as well as between piperaquine and mefloquine. The trial has completed the patient recruitment and the results are promising with high cure rates. However, recent increasing prevalence of parasite isolates with potential resistance to both mefloquine and piperaquine has questioned the longevity of the triple ACT [20].


7. Drug resistance in P. vivax

For the P. vivax, chloroquine remains the first line of treatment in majority of the endemic countries. However, after the first report from Papua New Guinea in 1989, chloroquine resistance has reached northern Papua and Indonesia. Later on, data with recurrences (by day-28 of chloroquine treatment) greater than 10% have also been reported from Myanmar, Thailand, Cambodia, India, Vietnam, Turkey, South America, Ethiopia and Madagascar [119]. Resistance in P. vivax is more difficult to document than for P. falciparum because of the relapses from liver stages. The most robust proof of resistance is given when a circulating parasite is detected in the peripheral blood in the presence of therapeutic chloroquine concentrations (i.e. >100 ng/ml). The absence of long-term parasite culture for P. vivax further complicates the efficacy testing in the laboratory, but short-term assays have been developed in recent years.


8. Regional artemisinin resistance initiative (RAI)

The six countries of the Greater Mekong Subregion (GMS), Thailand, Myanmar, Cambodia, Laos, Vietnam and China (Yunnan Province), are part of a larger community, the Association of Southeast Asian Nations (ASEAN). Despite political pledges to fight artemisinin resistance and eliminate malaria, coordination remains hampered by deep political, economic and geographical gaps. The WHO strategic plans to counter artemisinin resistance failed to prevent its spread to the entire sub-region. In 2013, the Global Fund launched the Regional Artemisinin-resistance Initiative to provide financial support to the five countries affected by this new treat. This initiative came in addition to the contributions of the Global Fund to the Malaria National Program and contributed to the decrease in malaria-related mortality and morbidity in the region. However, these efforts have been compromised by the fragmentation in the public health policies, the disparities in the infrastructures and human resources as well as corruption. In terms of treatment policies, all GMS countries had already adopted ACTs long before the emergence of resistance, but poor monitoring in some countries meant that monotherapies and sub-standard or counterfeit drugs continued to circulate until recently. The relative absence of entomological data in some parts of SEA explains that there is no coherent strategy for containment of local disease vectors. Large budgets continue to be spent on long-lasting impregnated nets (LLINs) despite the absence of evidence of their effectiveness.


9. Conclusions

Artemisinin resistance in P. falciparum has emerged 10 years ago in SEA and spread in the entire GMS. Parasite populations resistant to all ACTs are now circulating in Cambodia, triggering a resurgence of the disease. Current gains in malaria control/elimination program are heavily relying upon the efficacy of ACTs. The emergence of artemisinin and partner drug resistance is a serious threat to the global prospect of malaria elimination. The recent decline in the number of clinical cases in the region is encouraging but by no means a victory. Current resurgence of malaria in Cambodia and the existence of large reservoirs of sub-microscopic infections must be seen as warnings that malaria could make a devastating comeback. Efforts must continue and accelerate to eliminate the parasite and this will only be possible with stronger political will and sustained financial support. The three main programmatic components are EDT, elimination of the reservoirs and adapted vector control measures. The few antimalarials in the development pipeline are promising, though these compounds will not be ready on time to replace the ACTs [120]. The spread of the ACT-resistant malaria has so far outpaced the malaria containment measures and time is running out. There are not many options but to accelerate the current malaria elimination efforts.



We acknowledge the insightful suggestions of two editors from InTech Open Access. The Shoklo Malaria Research Unit and Myanmar Oxford Clinical Research Unit are part of the Mahidol Oxford Tropical Medicine Research Unit-Tropical health network funded by the Wellcome Trust.

List of acronyms

ACTartemisinin combination therapy
ASEANAssociation of Southeast Asian Nations
CNV(gene) copy number variation
EDTearly diagnosis and treatment
GMS Greater Mekong Subregion
K-13Kelch 13 gene of P. falciparum
LLINs long-lasting impregnated nets
MDAmass drug administration
MSATmass screening and treatment
PfcrtP. falciparum chloroquine resistance transporter
Pfmdr-1P. falciparum multi-drug resistant gene-1
PfPI3K P. falciparum phosphatidylinositol-3-kinase
Pgh1P-glycoprotein homologue 1
RBCred blood cell
SEASoutheast Asia
SNPsingle nucleotide polymorphism
UPRunfolded protein response pathway (UPR)
WWARNWorldwide Antimalarial Resistance Network
WHOWorld Health Organisation


  1. 1. Plowe CV, Wellems TE. Molecular approaches to the spreading problem of drug resistant malaria. In: Jungkind DL, Mortensen JE, Fraimow HS, Calandra GB, editors. Antimicrobial Resistance: A Crisis in Health Care. Boston, MA, USA: Springer; 1995. pp. 197-209
  2. 2. Wellems TE, Plowe CV. Chloroquine-resistant malaria. The Journal of Infectious Diseases. 2001;184(6):770-776
  3. 3. Najera JA, Gonzalez-Silva M, Alonso PL. Some lessons for the future from the global malaria eradication programme (1955-1969). PLoS Medicine. 2011;8(1):e1000412
  4. 4. Wellems TE, Hayton K, Fairhurst RM. The impact of malaria parasitism: From corpuscles to communities. The Journal of Clinical Investigation. 2009;119(9):2496-2505
  5. 5. Wongsrichanalai C, Pickard AL, Wernsdorfer WH, Meshnick SR. Epidemiology of drug-resistant malaria. The Lancet Infectious Diseases. 2002;2(4):209-218
  6. 6. Dondorp AM, Nosten F, Yi P, Das D, Phyo AP, Tarning J, et al. Artemisinin resistance in Plasmodium falciparum malaria. The New England Journal of Medicine. 2009;361(5):455-467
  7. 7. Nosten F, ter Kuile F, Chongsuphajaisiddhi T, Luxemburger C, Webster HK, Edstein M, et al. Mefloquine-resistant falciparum malaria on the Thai-Burmese border. Lancet. 1991;337(8750):1140-1143
  8. 8. Boudreau EF, Webster HK, Pavanand K, Thosingha L. Type II mefloquine resistance in Thailand. Lancet. 1982;2(8311):1335
  9. 9. Gates Foundation. Available from:
  10. 10. WHO. World malaria report 2017. Geneva: World Health Organization; 2017
  11. 11. Culleton RL, Abkallo HM. Malaria parasite genetics: Doing something useful. Parasitology International. 2015;64(3):244-253
  12. 12. White NJ. Antimalarial drug resistance. The Journal of Clinical Investigation. 2004;113(8):1084-1092
  13. 13. Maïga O, Djimdé AA, Hubert V, Renard E, Aubouy A, Kironde F, et al. A shared Asian origin of the triple-mutant dhfr allele in Plasmodium falciparum from sites across Africa. Journal of Infectious Diseases. 2007;196(1):165-172
  14. 14. Roper C, Pearce R, Nair S, Sharp B, Nosten F, Anderson T. Intercontinental spread of pyrimethamine-resistant malaria. Science. 2004;305
  15. 15. Cerqueira GC, Cheeseman IH, Schaffner SF, Nair S, McDew-White M, Phyo AP, et al. Longitudinal genomic surveillance of Plasmodium falciparum malaria parasites reveals complex genomic architecture of emerging artemisinin resistance. Genome Biology. 2017;18(1):78
  16. 16. Ariey F, Witkowski B, Amaratunga C, Beghain J, Langlois AC, Khim N, et al. A molecular marker of artemisinin-resistant Plasmodium falciparum malaria. Nature. 2014;505(7481):50-55
  17. 17. Miotto O, Amato R, Ashley EA, MacInnis B, Almagro-Garcia J, Amaratunga C, et al. Genetic architecture of artemisinin-resistant Plasmodium falciparum. Nature Genetics. 2015;47(3):226-234
  18. 18. Thomsen TT, Madsen LB, Hansson HH, Tomás EV, Charlwood D, Bygbjerg IC, et al. Rapid selection of Plasmodium falciparum chloroquine resistance transporter gene and multidrug resistance gene-1 haplotypes associated with past chloroquine and present artemether-lumefantrine use in Inhambane District, southern Mozambique. The American Journal of Tropical Medicine and Hygiene. 2013;88(3):536-541
  19. 19. Kublin JG, Cortese JF, Njunju EM, Mukadam G, RA WJJ, Kazembe PN, et al. Reemergence of chloroquine-sensitive Plasmodium falciparum malaria after cessation of chloroquine use in Malawi. The Journal of Infectious Diseases. 2003;187(12):1870-1875
  20. 20. Rossi G, De Smet M, Khim N, Kindermans J-M, Menard D. Emergence of Plasmodium falciparum triple mutant in Cambodia. The Lancet Infectious Diseases. 2017;17(12):1233
  21. 21. Payne D. Did medicated salt hasten the spread of chloroquine resistance in Plasmodium falciparum? Parasitology Today. 1988;4(4):112-115
  22. 22. Verdrager J. Localized permanent epidemics: The genesis of chloroquine resistance in Plasmodium falciparum. The Southeast Asian Journal of Tropical Medicine and Public Health. 1995;26(1):23-28
  23. 23. Verdrager J. Epidemiology of the emergence and spread of drug-resistant falciparum malaria in South-East Asia and Australasia. Journal of Tropical Medicine and Hygiene. 1986;89(6):277-289
  24. 24. Ataíde R, Powell R, Moore K, McLean A, Phyo AP, Nair S, et al. Declining transmission and immunity to malaria and emerging artemisinin resistance in Thailand: A longitudinal study. The Journal of Infectious Diseases. Sep 15, 2017;216(6):723-731
  25. 25. Phyo AP, Ashley EA, Anderson TJC, et al. Declining efficacy of artemisinin combination therapy against P. falciparum malaria on the Thai-Myanmar Border (2003-2013): The role of parasite genetic factors. Clinical Infectious Diseases. 2016;63:784-791
  26. 26. Amato R, Lim P, Miotto O, et al. Genetic markers associated with dihydroartemisinin-piperaquine failure in Plasmodium falciparum malaria in Cambodia: A genotype–phenotype association study. The Lancet Infectious Diseases. 2017;17:164-173
  27. 27. Simpson BB, Conner-Ogorzaly M. Economic Botany: Plants in our World. 3rd ed. Dubuque, Iowa: McGraw-Hill; 2000
  28. 28. da Silva AF, Benchimol JL. Malaria and quinine resistance: A medical and scientific issue between Brazil and Germany (1907-1919). Medical History. 2014;58(1):1-26
  29. 29. Werner H. Beobachtungen über relative Chininresistenz bei Malaria aus Brasilien. Deutsche Medizinische Wochenschrift. 1910;36(34):1557-1560
  30. 30. Ménard D, Andriantsoanirina V, Khim N, Ratsimbasoa A, Witkowski B, Benedet C, et al. Global analysis of Plasmodium falciparum Na(+)/H(+) exchanger (pfnhe-1) allele polymorphism and its usefulness as a marker of In vitro resistance to quinine. International Journal for Parasitology, Drugs and Drug Resistance. 2013;3:8-19
  31. 31. Menard D, Yapou F, Manirakiza A, Djalle D, Matsika-Claquin MD, Talarmin A. Polymor-phisms in pfcrt, pfmdr1, dhfr genes and In vitro responses to antimalarials in Plasmodium falciparum isolates from Bangui, Central African Republic. The American Journal of Tropical Medicine and Hygiene. 2006;75(3):381-387
  32. 32. Mayxay M, Barends M, Brockman A, Jaidee A, Nair S, Sudimack D, et al. In vitro antimalarial drug susceptibility and pfcrt mutation among fresh Plasmodium falciparum isolates from the Lao PDR (Laos). The American Journal of Tropical Medicine and Hygiene. 2007;76(2):245-250
  33. 33. Legrand E, Volney B, Meynard J-B, Mercereau-Puijalon O, Esterre P. In vitro monitoring of Plasmodium falciparum drug resistance in French Guiana: A synopsis of continuous assessment from 1994 to 2005. Antimicrobial Agents and Chemotherapy. 2008;52(1):288-298
  34. 34. Achan J, Talisuna AO, Erhart A, Yeka A, Tibenderana JK, Baliraine FN, et al. Quinine, an old anti-malarial drug in a modern world: Role in the treatment of malaria. Malaria Journal. 2011;10(1):144
  35. 35. Myint HY, Tipmanee P, Nosten F, Day NP, Pukrittayakamee S, Looareesuwan S, et al. A systematic overview of published antimalarial drug trials. Transactions of the Royal Society of Tropical Medicine and Hygiene. 2004;98(2):73-81
  36. 36. Coatney GR. Pitfalls in a discovery: The chronicle of chloroquine. The American Journal of Tropical Medicine and Hygiene. 1963;12:121-128
  37. 37. Ecker A, Lehane AM, Clain J, Fidock DA. PfCRT and its role in antimalarial drug resistance. Trends in Parasitology. 2012;28(11):504-514
  38. 38. Fidock DA, Nomura T, Talley AK, Cooper RA, Dzekunov SM, Ferdig MT, et al. Mutations in the P. falciparum digestive vacuole transmembrane protein PfCRT and evidence for their role in chloroquine resistance. Molecular Cell. 2000;6(4):861-871
  39. 39. Dzekunov SM, Ursos LMB, Roepe PD. Digestive vacuolar pH of intact intraerythrocytic P. falciparum either sensitive or resistant to chloroquine. Molecular and Biochemical Parasitology. 2000;110(1):107-124
  40. 40. Ariey F, Fandeur T, Durand R, Randrianarivelojosia M, Jambou R, Legrand E, et al. Invasion of Africa by a single pfcrt allele of south East Asian type. Malaria Journal. 2006;5(1):34
  41. 41. Payne D. Spread of chloroquine resistance in Plasmodium falciparum. Parasitology Today. 1987;3(8):241-246
  42. 42. Peters W. Resistance in human malaria IV: 4-aminoquinolines and multiple resistance. Chemotherapy and Drug Resistance in Malaria. 1987;2:659-786
  43. 43. Wongsrichanalai C, Sirichaisinthop J, Karwacki JJ, Congpuong K, Miller RS, Pang L, et al. Drug resistant malaria on the Thai-Myanmar and Thai-Cambodian borders. The Southeast Asian Journal of Tropical Medicine and Public Health. 2001;32(1):41-49
  44. 44. Pinichpongse S, Doberstyn EB, Cullen JR, Yisunsri L, Thongsombun Y, Thimasarn K. An evaluation of five regimens for the outpatient therapy of falciparum malaria in Thailand 1980-81. Bulletin of the World Health Organization. 1982;60(6):907-912
  45. 45. Cowman AF, Morry MJ, Biggs BA, Cross GA, Foote SJ. Amino acid changes linked to pyrimethamine resistance in the dihydrofolate reductase-thymidylate synthase gene of Plasmodium falciparum. Proceedings of the National Academy of Sciences of the United States of America. 1988;85(23):9109-9113
  46. 46. Peterson DS, Walliker D, Wellems TE. Evidence that a point mutation in dihydrofolate reductase-thymidylate synthase confers resistance to pyrimethamine in falciparum malaria. Proceedings of the National Academy of Sciences of the United States of America. 1988;85(23):9114-9118
  47. 47. Sirawaraporn W, Sathitkul T, Sirawaraporn R, Yuthavong Y, Santi DV. Antifolate-resistant mutants of Plasmodium falciparum dihydrofolate reductase. Proceedings of the National Academy of Sciences of the United States of America. 1997;94(4):1124-1129
  48. 48. Brooks DR, Wang P, Read M, Watkins WM, Sims PF, Hyde JE. Sequence variation of the hydroxymethyldihydropterin pyrophosphokinase: Dihydropteroate synthase gene in lines of the human malaria parasite, Plasmodium falciparum, with differing resistance to sulfadoxine. European Journal of Biochemistry/FEBS. 1994;224(2):397-405
  49. 49. Triglia T, Cowman AF. Primary structure and expression of the dihydropteroate synthetase gene of Plasmodium falciparum. Proceedings of the National Academy of Sciences of the United States of America. 1994;91(15):7149-7153
  50. 50. Nair S, Williams JT, Brockman A, Paiphun L, Mayxay M, Newton PN, et al. A selective sweep driven by pyrimethamine treatment in southeast asian malaria parasites. Molecular Biology and Evolution. 2003;20(9):1526-1536
  51. 51. Roper C, Pearce R, Bredenkamp B, Gumede J, Drakeley C, Mosha F, et al. Antifolate antimalarial resistance in Southeast Africa: A population-based analysis. The Lancet. 2003;361(9364):1174-1181
  52. 52. Venkatesan M, Gadalla NB, Stepniewska K, Dahal P, Nsanzabana C, Moriera C, et al. Polymorphisms in Plasmodium falciparum chloroquine resistance transporter and multidrug resistance 1 genes: Parasite risk factors that affect treatment outcomes for P. falciparum malaria after artemether-lumefantrine and artesunate-amodiaquine. The American Journal of Tropical Medicine and Hygiene. 2014;91(4):833-843
  53. 53. Folarin OA, Bustamante C, Gbotosho GO, Sowunmi A, Zalis MG, Oduola AMJ, et al. In vitro Amodiaquine resistance and its association with mutations in pfcrt and pfmdr1 genes of Plasmodium falciparum isolates from Nigeria. Acta Tropica. 2011;120(3):224-230
  54. 54. Happi C, Gbotosho G, Folarin O, Bolaji O, Sowunmi A, Kyle D, et al. Association between mutations in Plasmodium falciparum chloroquine resistance transporter and P. falciparum multidrug resistance 1 genes and in vivo amodiaquine resistance in P. falciparum malaria–infected children in Nigeria. The American Journal of Tropical Medicine and Hygiene. 2006;75(1):155-161
  55. 55. Holmgren G, Gil JP, Ferreira PM, Veiga MI, Obonyo CO, Björkman A. Amodiaquine resistant Plasmodium falciparum malaria in vivo is associated with selection of pfcrt 76T and pfmdr1 86Y. Infection, Genetics and Evolution. 2006;6(4):309-314
  56. 56. Young MD. Amodiaquine and hydroxychloroquine resistance in Plasmodium falciparum. The American Journal of Tropical Medicine and Hygiene. 1961;10:689-693
  57. 57. Young MD. Failure of chloroquine and amodiaquine to suppress Plasmodium falciparum. Transactions of the Royal Society of Tropical Medicine and Hygiene. 1962;56(3):252-256
  58. 58. Gascón J, Soldevila M, Merlos A, Bada JL. Chloroquine and amodiaquine resistant falciparum malaria in Rwanda. The Lancet. 1985;326(8463):1072
  59. 59. Doberstyn EB, Phintuyothin P, Noeypatimanondh S, Teerakiartkamjorn C. Single-dose therapy of falciparum malaria with mefloquine or pyrimethamine-sulfadoxine. Bulletin of the World Health Organization. 1979;57(2):275-279
  60. 60. Pinichpongse S, Suebsaeng L, Malikul S, Doberstyn E, Rooney W. The operational introduction of mefloquine, a new anti-malarial drug by the malaria program of Thailand. The Journal of Communicable Diseases – Thai. 1987;13:411-424
  61. 61. Wongsrichanalai C, Prajakwong S, Meshnick SR, Shanks GD, Thimasarn K. Mefloquine – Its 20 years in the Thai malaria control program. The Southeast Asian Journal of Tropical Medicine and Public Health. 2004;35(2):300-308
  62. 62. Thimasarn K, Sirichaisinthop J, Vijaykadga S, Tansophalaks S, Yamokgul P, Laomiphol A, et al. In vivo study of the response of Plasmodium falciparum to standard mefloquine/sulfadoxine/pyrimethamine (MSP) treatment among gem miners returning from Cambodia. The Southeast Asian Journal of Tropical Medicine and Public Health. 1995;26(2):204-212
  63. 63. Nosten F, Imvithaya S, Vincenti M, Delmas G, Lebihan G, Hausler B, et al. Malaria on the Thai-Burmese border: Treatment of 5192 patients with mefloquine-sulfadoxine-pyrimethamine. Bulletin of the World Health Organization. 1987;65(6):891-896
  64. 64. Anderson TJ, Patel J, Ferdig MT. Gene copy number and malaria biology. Trends in Parasitology. 2009;25(7):336-343
  65. 65. Alker AP, Lim P, Sem R, Shah NK, Yi P, Bouth DM, et al. Pfmdr1 and in vivo resistance to artesunate-mefloquine in falciparum malaria on the Cambodian-Thai border. The American Journal of Tropical Medicine and Hygiene. 2007;76(4):641-647
  66. 66. Lim P, Alker AP, Khim N, Shah NK, Incardona S, Doung S, et al. Pfmdr1 copy number and arteminisin derivatives combination therapy failure in falciparum malaria in Cambodia. Malaria Journal. 2009;8:11
  67. 67. Price RN, Uhlemann AC, Brockman A, McGready R, Ashley E, Phaipun L, et al. Mefloquine resistance in Plasmodium falciparum and increased pfmdr1 gene copy number. Lancet. 2004;364(9432):438-447
  68. 68. Price RN, Cassar C, Brockman A, Duraisingh M, van Vugt M, White NJ, et al. The pfmdr1 gene is associated with a multidrug-resistant phenotype in Plasmodium falciparum from the western border of Thailand. Antimicrobial Agents and Chemotherapy. 1999;43(12):2943-2949
  69. 69. Preechapornkul P, Imwong M, Chotivanich K, Pongtavornpinyo W, Dondorp AM, Day NP, et al. Plasmodium falciparum pfmdr1 amplification, mefloquine resistance, and parasite fitness. Antimicrobial Agents and Chemotherapy. 2009;53(4):1509-1515
  70. 70. Sidhu AB, Uhlemann AC, Valderramos SG, Valderramos JC, Krishna S, Fidock DA. Decreasing pfmdr1 copy number in Plasmodium falciparum malaria heightens susceptibility to mefloquine, lumefantrine, halofantrine, quinine, and artemisinin. The Journal of Infectious Diseases. 2006;194(4):528-535
  71. 71. Lim P, Dek D, Try V, Sreng S, Suon S, Fairhurst RM. Decreasing pfmdr1 copy number suggests that Plasmodium falciparum in Western Cambodia is regaining In vitro susceptibility to mefloquine. Antimicrobial Agents and Chemotherapy. 2015;59(5):2934-2937
  72. 72. Looareesuwan S, Chulay JD, Canfield CJ, Hutchinson DB. Malarone (atovaquone-proguanil hydrochloride): A review of its clinical development for treatment of malaria. Malarone Clinical Trials Study Group. The American Society of Tropical Medicine and Hygiene. 1999;60(4):533-541
  73. 73. Looareesuwan S, Viravan C, Webster HK, Kyle DE, Hutchinson DB, Canfield CJ. Clinical studies of atovaquone, alone or in combination with other antimalarial drugs, for treatment of acute uncomplicated malaria in Thailand. The American Journal of Tropical Medicine and Hygiene. 1996;54(1):62-66
  74. 74. Gil JP, Nogueira F, Stromberg-Norklit J, Lindberg J, Carrolo M, Casimiro C, et al. Detection of atovaquone and Malarone resistance conferring mutations in Plasmodium falciparum cytochrome b gene (cytb). Molecular and Cellular Probes. 2003;17(2-3):85-89
  75. 75. Korsinczky M, Chen N, Kotecka B, Saul A, Rieckmann K, Cheng Q. Mutations in Plasmodium falciparum cytochrome b that are associated with atovaquone resistance are located at a putative drug-binding site. Antimicrobial Agents and Chemotherapy. 2000;44(8):2100-2108
  76. 76. Gassis S, Rathod PK. Frequency of drug resistance in Plasmodium falciparum: A nonsynergistic combination of 5-fluoroorotate and atovaquone suppresses In vitro resistance. Antimicrobial Agents and Chemotherapy. 1996;40(4):914-919
  77. 77. Rathod PK, McErlean T, Lee PC. Variations in frequencies of drug resistance in Plasmodium falciparum. Proceedings of the National Academy of Sciences of the United States of America. 1997;94(17):9389-9393
  78. 78. Srivastava IK, Morrisey JM, Darrouzet E, Daldal F, Vaidya AB. Resistance mutations reveal the atovaquone-binding domain of cytochrome b in malaria parasites. Molecular Microbiology. 1999;33(4):704-711
  79. 79. Pradines B, Mamfoumbi MM, Parzy D, Medang MO, Lebeau C, Mbina JM, et al. In vitro susceptibility of African isolates of Plasmodium falciparum from Gabon to pyronaridine. The American Journal of Tropical Medicine and Hygiene. 1999;60(1):105-108
  80. 80. Wells TN, van Huijsduijnen RH, Van Voorhis WC. Malaria medicines: A glass half full? Nature Reviews Drug Discovery. 2015;14(6):424-442
  81. 81. Leang R, Canavati SE, Khim N, Vestergaard LS, Fuhrer IB, Kim S, et al. Efficacy and safety of pyronaridine-artesunate for treatment of uncomplicated Plasmodium falciparum malaria in western Cambodia. Antimicrobial Agents and Chemotherapy. 2016;60(7):3884-3890
  82. 82. Pascual A, Madamet M, Bertaux L, Amalvict R, Benoit N, Travers D, et al. In vitro piperaquine susceptibility is not associated with the Plasmodium falciparum chloroquine resistance transporter gene. Malaria Journal. 2013;12(1):1-6
  83. 83. Briolant S, Henry M, Oeuvray C, Amalvict R, Baret E, Didillon E, et al. Absence of association between piperaquine In vitro responses and polymorphisms in the pfcrt, pfmdr1, pfmrp, and pfnhe genes in Plasmodium falciparum. Antimicrobial Agents and Chemotherapy. 2010;54
  84. 84. Eastman RT, Dharia NV, Winzeler EA, Fidock DA. Piperaquine resistance is associated with a copy number variation on chromosome 5 in drug-pressured Plasmodium falciparum parasites. Antimicrobial Agents and Chemotherapy. 2011;55(8):3908-3916
  85. 85. Duru V, Khim N, Leang R, Kim S, Domergue A, Kloeung N, et al. Plasmodium falciparum dihydroartemisinin-piperaquine failures in Cambodia are associated with mutant K13 parasites presenting high survival rates in novel piperaquine In vitro assays: Retrospective and prospective investigations. BMC Medicine. 2015;13(1):1
  86. 86. Amaratunga C, Lim P, Suon S, Sreng S, Mao S, Sopha C, et al. Dihydroartemisinin–piperaquine resistance in Plasmodium falciparum malaria in Cambodia: A multisite prospective cohort study. The Lancet Infectious Diseases. 2016;16(3):357-365
  87. 87. Witkowski B, Duru V, Khim N, Ross LS, Saintpierre B, Beghain J, et al. A surrogate marker of piperaquine-resistant Plasmodium falciparum malaria: A phenotype–genotype association study. The Lancet Infectious Diseases. 2017;17(2):174-183
  88. 88. Haldar K, Bhattacharjee S, Safeukui I. Drug resistance in Plasmodium. Nature Reviews Microbiology. 2018;16(3):156-170
  89. 89. Mohon AN, Alam MS, Bayih AG, Folefoc A, Shahinas D, Haque R, et al. Mutations in Plasmodium falciparum K13 propeller gene from Bangladesh (2009-2013). Malaria Journal. 2014;13:431
  90. 90. Mita T, Tachibana S-I, Hashimoto M, Hirai M. Plasmodium falciparum kelch 13: A potential molecular marker for tackling artemisinin-resistant malaria parasites. Expert Review of Anti-infective Therapy. 2016;14(1):125-135
  91. 91. Mbengue A, Bhattacharjee S, Pandharkar T, Liu H, Estiu G, Stahelin RV, et al. A molecular mechanism of artemisinin resistance in Plasmodium falciparum malaria. Nature. 2015;520(7549):683-687
  92. 92. Bhattacharjee S, Stahelin RV, Speicher KD, Speicher DW, Haldar K. Endoplasmic reticulum PI(3)P lipid binding targets malaria proteins to the host cell. Cell. 2012;148(1-2):201-212
  93. 93. Tawk L, Chicanne G, Dubremetz JF, Richard V, Payrastre B, Vial HJ, et al. Phos-phatidylinositol 3-phosphate, an essential lipid in Plasmodium, localizes to the food vacuole membrane and the apicoplast. Eukaryotic Cell. 2010;9(10):1519-1530
  94. 94. Vaid A, Ranjan R, Smythe WA, Hoppe HC, Sharma P. PfPI3K, a phosphatidylinositol-3 kinase from Plasmodium falciparum, is exported to the host erythrocyte and is involved in hemoglobin trafficking. Blood. 2010;115(12):2500-2507
  95. 95. Cheeseman IH, Miller BA, Nair S, Nkhoma S, Tan A, Tan JC, et al. A major genome region underlying artemisinin resistance in malaria. Science. 2012;336(6077):79-82
  96. 96. Miotto O, Almagro-Garcia J, Manske M, Macinnis B, Campino S, Rockett KA, et al. Multiple populations of artemisinin-resistant Plasmodium falciparum in Cambodia. Nature Genetics. 2013;45(6):648-655
  97. 97. Takala-Harrison S, Clark TG, Jacob CG, Cummings MP, Miotto O, Dondorp AM, et al. Genetic loci associated with delayed clearance of Plasmodium falciparum following artemisinin treatment in Southeast Asia. Proceedings of the National Academy of Sciences of the United States of America. 2013;110(1):240-245
  98. 98. Painter HJ, Campbell TL, Llinas M. The Apicomplexan AP2 family: Integral factors regulating Plasmodium development. Molecular and Biochemical Parasitology. 2011;176(1):1-7
  99. 99. Mok S, Ashley EA, Ferreira PE, Zhu L, Lin Z, Yeo T, et al. Drug resistance. Population transcriptomics of human malaria parasites reveals the mechanism of artemisinin resistance. Science. 2015;347(6220):431-435
  100. 100. Nosten F. Waking the sleeping beauty. Journal of Infectious Diseases. 2010;202(9):1300-1301
  101. 101. Anderson TJ, Nair S, McDew-White M, Cheeseman IH, Nkhoma S, Bilgic F, et al. Population parameters underlying an ongoing soft sweep in southeast Asian malaria parasites. Molecular Biology and Evolution. Jan 2017;34(1):131-144
  102. 102. White N. Antimalarial drug resistance and combination chemotherapy. Philosophical Transactions of the Royal Society of London Series B, Biological Sciences. 1999;354(1384):739-749
  103. 103. Jeffery GM, Eyles DE. Infectivity to mosquitoes of Plasmodium falciparum as related to gametocyte density and duration of infection. The American Journal of Tropical Medicine and Hygiene. 1955;4(5):781-789
  104. 104. Bousema T, Drakeley C. Epidemiology and infectivity of Plasmodium falciparum and Plasmodium vivax gametocytes in relation to malaria control and elimination. Clinical Microbiology Reviews. 2011;24(2):377-410
  105. 105. Barnes KI, White NJ. Population biology and antimalarial resistance: The transmission of antimalarial drug resistance in Plasmodium falciparum. Acta Tropica. 2005;94(3):230-240
  106. 106. Ashley EA, Dhorda M, Fairhurst RM, Amaratunga C, Lim P, Suon S, et al. Spread of artemisinin resistance in Plasmodium falciparum malaria. The New England Journal of Medicine. 2014;371(5):411-423
  107. 107. Barnes KI, Little F, Mabuza A, Mngomezulu N, Govere J, Durrheim D, et al. Increased gametocytemia after treatment: An early parasitological indicator of emerging sulfadoxine-pyrimethamine resistance in falciparum malaria. The Journal of Infectious Diseases. 2008;197(11):1605-1613
  108. 108. Hallett RL, Dunyo S, Ord R, Jawara M, Pinder M, Randall A, et al. Chloroquine/sulphadoxine-pyrimethamine for gambian children with malaria: Transmission to mosquitoes of multidrug-resistant Plasmodium falciparum. PLoS Clinical Trials. 2006;1(3):e15
  109. 109. Méndez F, Muñoz Á, Carrasquilla G, Jurado D, Arévalo-Herrera M, Cortese JF, et al. Determinants of treatment response to sulfadoxine-pyrimethamine and subsequent transmission potential in falciparum malaria. American Journal of Epidemiology. 2002;156(3):230-238
  110. 110. Price R, Nosten F, Simpson JA, Luxemburger C, Phaipun L, Ter Kuile F, et al. Risk factors for gametocyte carriage in uncomplicated falciparum malaria. The American Journal of Tropical Medicine and Hygiene. 1999;60(6):1019-1023
  111. 111. Bousema T, Griffin JT, Sauerwein RW, Smith DL, Churcher TS, Takken W, et al. Hitting hotspots: Spatial targeting of malaria for control and elimination. PLoS Medicine. 2012;9(1):e1001165
  112. 112. Cotter C, Sturrock HJ, Hsiang MS, Liu J, Phillips AA, Hwang J, et al. The changing epidemiology of malaria elimination: New strategies for new challenges. Lancet. 2013;382(9895):900-911
  113. 113. Sturrock HJ, Hsiang MS, Cohen JM, Smith DL, Greenhouse B, Bousema T. Targeting asymptomatic malaria infections: Active surveillance in control and elimination. PLoS Medicine. 2013;10(6):e1001467
  114. 114. Landier J, Parker DM, Thu AM, Carrara VI, Lwin KM, Bonnington CA, et al. The role of early detection and treatment in malaria elimination. Malaria Journal. 2016;15(1):363
  115. 115. Kajeechiwa L, Thwin MM, Nosten S, Tun SW, Parker D, von Seidlein L, et al. Community engagement for the rapid elimination of malaria: The case of Kayin State, Myanmar. Wellcome Open Research. Jul 28, 2017;2:59
  116. 116. Landier J, Parker D, Thu AM, Lwin KM, Delmas G, Nosten F. A regional P. falciparum malaria elimination programme in Eastern Myanmar: Impact of generalized access to early diagnosis and treatment and targeted mass drug administration. The Lancet. 2018 (in press)
  117. 117. Parker DM, Landier J, Thu AM, Lwin KM, Delmas G, Nosten FH. Scale up of a Plasmodium falciparum elimination program and surveillance system in Kayin State, Myanmar. Wellcome Open Research. 2017;2:98
  118. 118. Thanh NV, Thuy-Nhien N, Tuyen NTK, Tong NT, Nha-Ca NT, Quang HH, et al. Rapid decline in the susceptibility of Plasmodium falciparum to dihydroartemisinin–piperaquine in the south of Vietnam. Malaria Journal. 2017;16(1):27
  119. 119. Price RN, von Seidlein L, Valecha N, Nosten F, Baird JK, White NJ. Global extent of chloroquine-resistant Plasmodium vivax: A systematic review and meta-analysis. The Lancet Infectious Diseases. 2014;14(10):982-991
  120. 120. Phyo AP, Seidlein L. Challenges to replace ACT as first-line drug. Malaria Journal. 2017;16(1):296
  121. 121. WHO. Artemisinin and Artemisinin based Combination Therapy Resistance: World Health Organization. 2016
  122. 122. Srimuang K, Miotto O, Lim P, Fairhurst RM, Kwiatkowski DP, Woodrow CJ, et al. Analysis of anti-malarial resistance markers in pfmdr1 and pfcrt across Southeast Asia in the tracking resistance to Artemisinin collaboration. Malaria Journal. 2016;15(1):541
  123. 123. Mishra N, Bharti RS, Mallick P, Singh OP, Srivastava B, Rana R, et al. Emerging polymorphisms in falciparum Kelch 13 gene in Northeastern region of India. Malaria Journal. 2016;15(1):583
  124. 124. Tun KM, Jeeyapant A, Imwong M, Thein M, Aung SS, Hlaing TM, et al. Parasite clearance rates in upper Myanmar indicate a distinctive artemisinin resistance phenotype: A therapeutic efficacy study. Malaria Journal. 2016;15(1):185
  125. 125. Imwong M, Suwannasin K, Kunasol C, Sutawong K, Mayxay M, Rekol H, et al. The spread of artemisinin-resistant Plasmodium falciparum in the greater Mekong subregion: A molecular epidemiology observational study. The Lancet Infectious Diseases. May 2017;17(5):491-497
  126. 126. Ye R, Hu D, Zhang Y, Huang Y, Sun X, Wang J, et al. Distinctive origin of artemisinin-resistant Plasmodium falciparum on the China-Myanmar border. Scientific Reports. 2016;6:20100
  127. 127. Arrow KJ, Panosian C, Gelband H, editors. In: Saving Lives, Buying Time: Economics of Malaria Drugs in an Age of Resistance. Washington (DC): National Academies Press; 2004. ISBN: 0309092183
  128. 128. Wernsdorfer WH, Payne D. The dynamics of drug resistance in Plasmodium falciparum. Pharmacology & Therapeutics. 1991;50(1):95-121
  129. 129. Maberti S. Desarrollo de Resistencia a Ia pirimetamina. Presentación de 15 casos estudiados en Trujillo, Venezuela. Archivos Venezolanos de Medicina Tropical y Parasitología Médica. 1960;3:239-259
  130. 130. Moore DV, Lanier JE. Observations on two Plasmodium falciparum infections with an abnormal response to chloroquine. The American Journal of Tropical Medicine and Hygiene. 1961;10:5-9
  131. 131. Berliner RW. Studies on the chemotherapy of the human malarias; of the human malarias the physiological disposition, antimalarial activity, and toxicity of several derivatives of 4-aminoquinoline. Journal of Clinical Investigation. 1948;27(3 Pt1):98-107
  132. 132. Hoekenga MT. Camoquin treatment of malaria: A preliminary report. The American Journal of Tropical Medicine and Hygiene. 1950;s1–s30(1):63-69
  133. 133. Covell G. “Paludrine” (Proguanil) in prophylaxis and treatment of malaria. British Medical Journal. 1949;1(4593):88-91
  134. 134. Kay HEM. Resistance to proguanil. The Lancet. 1949;253(6556):712
  135. 135. Harinasuta T, Viravan C, Reid HA. Sulphormethoxine in chloroquine-resistant falciparum malaria in Thailand. Lancet. 1967;1(7500):1117-1119
  136. 136. Canfield CJ, Hall AP, MacDonald BS, Neuman DA, Shaw JA. Treatment of falciparum malaria from Vietnam with a phenanthrene methanol (WR 33063) and a quinoline methanol (WR 30090). Antimicrobial Agents and Chemotherapy. 1973;3(2):224-227
  137. 137. Davis TME, Hung TY, Sim IK, Karunajeewa HA, Ilett KF. Piperaquine: A resurgent antimalarial drug. Drugs. 2005;65(1):75-87
  138. 138. Liu DQ. Surveillance of antimalarial drug resistance in China in the 1980s–1990s. Infectious Diseases of Poverty. 2014;3(1):8
  139. 139. Tu Y. The discovery of artemisinin (qinghaosu) and gifts from Chinese medicine. Nature Medicine. 2011;17(10):1217-1220
  140. 140. Nosten F, Luxemburger C, ter Kuile FO, Woodrow C, Eh JP, Chongsuphajaisiddhi T, et al. Treatment of multidrug-resistant Plasmodium falciparum malaria with 3-day artesunate-mefloquine combination. The Journal of Infectious Diseases. 1994;170(4):971-977
  141. 141. Wongsrichanalai C, Meshnick SR. Declining artesunate-mefloquine efficacy against falciparum malaria on the Cambodia-Thailand border. Emerging Infectious Diseases. 2008;14(5):716-719
  142. 142. Premji ZG. Coartem®: The Journey to the Clinic. Malaria Journal. 2009;8(1):S3
  143. 143. Denis MB, Tsuyuoka R, Lim P, Lindegardh N, Yi P, Top SN, et al. Efficacy of artemether-lumefantrine for the treatment of uncomplicated falciparum malaria in Northwest Cambodia. Tropical Medicine & International Health. 2006;11(12):1800-1807
  144. 144. Song J, Socheat D, Tan B, Seila S, Xu Y, Ou F, et al. Randomized trials of artemisinin-piperaquine, dihydroartemisinin-piperaquine phosphate and artemether-lumefantrine for the treatment of multi-drug resistant falciparum malaria in Cambodia-Thailand border area. Malaria Journal. 2011;10:231
  145. 145. Denis MB, Davis TM, Hewitt S, Incardona S, Nimol K, Fandeur T, et al. Efficacy and safety of dihydroartemisinin-piperaquine (Artekin) in Cambodian children and adults with uncomplicated falciparum malaria. Clinical Infectious Diseases. 2002;35(12):1469-1476
  146. 146. Leang R, Taylor WR, Bouth DM, Song L, Tarning J, Char MC, et al. Evidence of Plasmodium falciparum malaria multidrug resistance to Artemisinin and Piperaquine in western Cambodia: Dihydroartemisinin-piperaquine open-label multicenter clinical assessment. Antimicrobial Agents and Chemotherapy. 2015;59(8):4719-4726
  147. 147. Spring MD, Lin JT, Manning JE, Vanachayangkul P, Somethy S, Bun R, et al. Dihydro-artemisinin-piperaquine failure associated with a triple mutant including kelch13 C580Y in Cambodia: An observational cohort study. The Lancet Infectious Diseases. 2015;15(6):683-691

Written By

Aung Pyae Phyo and François Nosten

Submitted: 13 June 2017 Reviewed: 15 March 2018 Published: 18 July 2018