**1.1 Malaria - a global infectious disease**

Malaria is a global deadly communicable disease [1], caused by plasmodium species, an apicomplexan microbe transmitted by the mosquito vector. Five major plasmodia parasites (*P falciparum, P vivax, P ovale, P malariae* and *P knowlesi*) have been implicated in malaria infections [2]. Of these, *Plasmodium falciparum* (*P. falciparum*) and *Plasmodium vivax (P. vivax)* are more widely distributed [3]. In sub-Saharan Africa, *P. falciparum* is the cause of most malaria cases while *P. vivax* is reported to cause most of the malaria cases in Asia; *P. falciparum* cause more fatal disease [4].

In 2019 alone, about 229 million positive malaria infections were reported globally, mortality from was estimated at about 409,000, with children under 5 years accounting for about 67% of death [5]. The disease is common among in poor communities [6], especially rural communities of the underdeveloped/ developing countries of the world. Economic, social and health importance of this disease in terms of loss of life (particularly; young children), reduction in productivity of affected adult population, and negative social and health implication of the disease makes it one of the high ranking microbial, infectious disease in the world.

#### **1.2 Malaria elimination agenda**

Among the diseases which have great public health impact, malaria is a significant public health concern [7–9]. The fight to eliminate malaria is an aged long battle globally. Elimination programmes were launched after the Second World War [6], with chloroquine as the major frontline anti-malaria drug [10] and Dichlorodiphenyltrichloroethane DDT used for vector control [11]. Malaria eliminations efforts in Africa began with the World Health Organisation (WHO) roll back malaria initiatives started in 1998 [1]; these efforts focused on entomology control (to reduce transmitting vectors) using indoor insecticides, and treated mosquito nets introduced for protection and prevention [6].

The success of these elimination programmes is why over one hundred countries have been awarded malaria free status [12] and thirty-four others accorded elimination status [13], and most malaria endemic countries working very hard towards the attainment of elimination status. Today the disease burden continues to decrease across the world [14] relative to the era, before the launch of the global elimination programmes.

Success stories leading to this elimination stage in malaria control had been heavily dependent on traditional entomology surveillance and drug use. However, the plasmodium is a ubiquitous parasites that has evolved, complex systems of survival [15]. Among these survival strategies is the development of drug resistance to nearly all know malaria drugs. Resistance to chloroquine (the major frontline medicine for the treatment of malaria) was reported and widespread [13] long before the roll-back-malaria initiatives. Better understanding of the biology of the parasites and the life cycle led to the development of a range of other anti-malaria drugs some of which are still actively being used, but resistance to almost all know malaria drugs have been reported [16–19].

Drug resistance vary, and is transferable from pathogen to host [20]. Of the different types of drug resistance, adaptive drug resistance is usually not permanent, but is capable of producing strains of parasites not targeted by known drugs. This chapter aims at reviewing the different types of drug resistance with focus on adaptive drug resistance in plasmodium and the implication to malaria elimination programme.

#### **2. Brief history of anti-malaria drug resistance**

The fight against drug resistance in pathogenic microbes is global. The life of these microbes are so inter-twined with human wellness that if overlooked could be very costly in terms of treatment cost and loss of life. As efforts are being up-scaled towards malaria elimination, the issue of drug resistance continues to surface as a major challenge to cope with. This is because the malaria parasite continues to evolve and regularly develop mechanisms for surviving the toxic effect of drugs. These mechanisms result with fixed mutations in the genetic architecture that confers fitness and resistance to withstand or evade targeting drugs, thereby hindering or completely preventing binding between drug compounds and their target.

The history of evolution of drug resistance in plasmodium dates back to the 1930s when chloroquine (CQ ) resistance in *P. falciparum* arose independently in Columbia and Thailand [21], and rapidly spread throughout the world. Research efforts to truncate this spread led to the development of different variants of malaria drugs to replace CQ. However, the plasmodium in it's unique way continue to adapt and evolve new mutations for survival and resistance to drugs which are harmful to it [22]. Advances in molecular technology has made it possible to

*Adaptive Drug Resistance in Malaria Parasite: A Threat to Malaria Elimination Agenda? DOI: http://dx.doi.org/10.5772/intechopen.98323*


#### **Table 1.**

*Common mutations associated with* P. falciparum *malaria drug resistance.*

uncover different mutations in the plasmodium parasites associated with drug resistance (**Table 1**). Evolution of these mutations are dynamic and difficult could be difficult to track and eliminate, especially when novel parasite results, against which known anti-malaria drugs is ineffective.
