Cultivation of artemesia annua in Africa and Asia

Introduction The malaria parasite Plasmodium falciparum is one of the world’s most lethal pests, accounting for over a million deaths per year. 90% of cases are in Sub-Saharan Africa, 85% in children under five. For over 50 years the main tool for controlling the malaria parasite1 has been chloroquine, a synthetic derivative of the plant-based extract quinine. Chloroquine acts as both prophylactic and cure and has the advantage of very low cost ($0.10 per treatment), but unfortunately in much of Africa as well as South-East Asia it is no longer effective due to the emergence of resistant strains of the malaria parasite. The best hope for a replacement treatment lies with drugs based on artemisinin, a chemical extracted from the leaves of the plant Artemisia annua.

Artemisia annua is an annual shrub indigenous to China, but able to grow in a wide range of sub-tropical and temperate environments. Its use in treating malaria has been known in China for over 2000 years. The active ingredient, artemisinin, was isolated by Chinese scientists in 19722 . Derivatives which are more effective than artemisinin itself have been developed over the last 20 years. Attempts to produce synthetic and semi-synthetic artemisinin are ongoing, but the viability of this approach is not yet clear. Resistance to artemisinin drugs will inevitably appear in time, but the plant-based extract is still believed to have a useful life of at least 10 years3 .

This article describes programmes for expanding cultivation of Artemisia annua in Africa and Asia, and analyses Keywords: Artemisia annua, smallholder cultivation, artemisinin extraction, malaria control, China, East Africa prospects for extraction, manufacture and distribution of artemisinin-based anti-malarial drugs in the light of the WHO target of halving the incidence of malaria by 2015 and eliminating the disease thereafter.