For Research Use Only. Not for Clinical Use.

Introduction of Malaria

Malaria is a protozoan disease transmitted by Anopheles female mosquitoes and results from the infection of a vulnerable host by Plasmodium parasites. Of the more than 120 Plasmodium species known to exist, only five cause malarial infections in humans Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale, Plasmodium malaria, and Plasmodium knowlesi. P. falciparum accounts for most of the mortality, accounting for over 99% of all malaria-associated deaths globally. Although P. vivax has been traditionally considered to cause uncomplicated malaria, there is evidence of its potential to cause severe disease. P. knowlesi is a parasite transmitted from primates to humans that can also cause severe manifestations. P. malariae and P. ovale cause uncomplicated malaria, although rarely can associate other complications. Malaria caused an estimated 228 million clinical cases and 405,000 deaths in 2018. 94% of all deaths occurred in Sub-Saharan Africa. The greatest burden of severe disease is borne by children under 5 years of age which represents 67% of global deaths.

Fig. 1 Global distribution of P falciparum drug resistance. (Plewes, 2019)

Application of Half-life Extended Drug in Malaria

Malaria is a potent and constant threat to public health in much of the developing world. In principle, it could be controlled by preventative public health measures, but in practice, most control is at the level of disease management through drug treatment. Even small decreases in drug efficacy can substantially increase mortality rates and drug-resistant malaria carries serious cost implications for the developing world. There are relatively few classes of antimalarial drugs and the most effective means of using these drugs is still a subject for debate. In particular, the definition of optimal patterns of use for drugs with very different pharmacokinetic properties remains unresolved.

Fig.2 Stage of parasite development and pathogenicity with rough estimates of stage specificity and 'time windows' of anti-malarial drug effects. (Plewes, 2019)

Drugs with a long elimination half-life have two valuable therapeutic properties. First, they can provide long-term protection against reinfection. Prolonged antimalarial drug activity in vivo is an advantage to the patient who is recovering from malaria in an area of moderate or high transmission because further disease episodes are prevented. This assists recovery from anemia, a major cause of malaria morbidity and a contributor to mortality. Similarly, in epidemic malaria, where the population is highly susceptible and the clinical attack rate can approach 100%, but where the epidemic is of short duration and infrequent, long half-life drugs are of value. Second, long half-life drugs require a few (or only a single) administrations, which reduces the risk of under dosage and some of the problems of compliance.

Half-life extended drugs provide malaria researchers with new directions. Creative Biolabs simply clarifies the importance of applications of half-life extended drugs in malaria and has established a comprehensive technology platform offering global clients one-stop half-life extension research services. If you are focusing on half-life extension, or any one of our services, please feel free to contact us for professional answers from the Ph.D. level scientist team.

Reference

1. Plewes, K.; et al. Malaria: What's New in the Management of Malaria? Infect Dis Clin North Am. 2019, 33(1): 39-60.