WHO Releases Guidelines on Best Practices To Cultivate A. Annua for Malaria Treatments

The World Health Organization on Monday released guidelines on the cultivation and collection of Artemisia annua, the plant from which artemisinin-based combination therapies are derived, and said that overplanting of the shrub could undermine the effectiveness of ACTs, Reuters reports (Reuters, 3/12). The guidelines aim to improve the quality of A. annua for ACTs and help ensure that there is an adequate supply of the drugs to meet the demand. WHO since 2001 has recommended that countries use ACTs as first-line malaria treatments because of the disease's increasing resistance to older drugs. The demand for ACTs since then has increased rapidly (Xinhuanet, 3/13). Of the roughly 600 million people worldwide who need access to the drugs, approximately 82 million are receiving them through public-sector distribution systems, WHO said. Not all artemisinin meets the standards needed to manufacture high-quality ACTs, therefore it is crucial to promote the best practices in cultivating A. annua and manufacturing the drug, according to WHO. Artemisinin's contents and efficacy depend on climatic, geographic and environmental factors. In addition, the quality of the soil and rainfall can determine the artemisnin content and value in A. annua plants. Pilot tests of cultivation on small areas of land are required to determine whether the land can produce high-yield plants. It takes at least six months to cultivate A. annua and another two to five months to extract, process and manufacture the final product depending on the product formulation, WHO said. The quality of the plant can be damaged if it is exposed to high temperatures in the post-harvest process. In addition, the content of the leaves on the plant tend to decrease after it is harvested, and the value of the raw material for extraction can diminish after six to 12 months in storage, according to WHO. The agency recommends governments ensure that farmers and manufacturers work together to ascertain the demand for the plant. Recent experience has shown that overproduction of A. annua can waste time and money, as well as have adverse effects on the plant's future yield. In addition, governments should ensure that workers have the technical skills required to extract artemisinin from dried leaves, WHO said. The guidelines are based on research and practical experience in several countries that have successfully produced high volumes of A. annua using good cultivation practices. WHO aims to use the guidelines to serve as a model for countries and researchers to develop good agricultural and cultivation practices for other medicinal plants (WHO release, 3/12).