December 12, 2006. Copyright, 2006, Graphic News. All rights reserved

White House malaria summit

LONDON, December 12, Graphic News: Experts from the United States and Africa will meet Thursday (December 14) in Washington to develop a blueprint for controlling malaria, a disease that kills one person worldwide every 30 seconds.

Between 1.3 million and 3 million people die each year from the mosquito-borne blood infection, according to U.S. government estimates.

The ÒChallenge of Malaria in AfricaÓ summit, hosted by President and Mrs Bush, will offer U.S. government experts, the private sector, several African countries and non-governmental organizations a forum to discuss and highlight measures for fighting the disease.

In early December, the World Health Organisation (WHO) launched a new global effort to find a vaccine against the disease. The Malaria Vaccine Technology Roadmap aims to develop and licence a first generation vaccine by 2015 that is 50-percent effective and would last longer than one year.

In 2001, the WHO recommended using therapies containing artemisinin, a compound extracted from the dry leaves of a Chinese herb called qinghao (Artemisia annua, sweet Annie or sweet wormwood).

Last year, in the largest clinical trial ever conducted into the treatment of severe malaria, medication derived from artemisinin reduced the number of deaths by more than a third when compared with quinine, the most popularly used treatment.

The trial, funded by the Wellcome Trust, was conducted amongst 1,500 patients in Bangladesh, Myanmar, India and Indonesia, to compare the effectiveness of quinine and artemisinin. The results were compelling: the artemisinin-derived drug reduced mortality by 35 percent when compared with quinine, and was safer and easier to administer.

Professor Nick White, Director of the Wellcome TrustÕs South-east Asia Major Overseas Programme, said ÒArtesunate [artemisinin] is widely used in a tablet form, as part of a combination therapy, to treat patients with the early stages of malaria. This is now accepted as the best treatment for uncomplicated malaria. These remarkable results should bring an immediate change in WHO recommendations for severe malaria.Ó

Quinghaosu (extract of green herb) has been used to treat malaria and fevers in China for over 1,500 years. In 1596 ChinaÕs greatest naturalist, Li Shih-Chen, described the use of A. annua: Òtake a handful of sweet wormwood, soak it in a sheng (litre) of water, and squeeze out the juice and drink it allÓ.

The plant has a strong aromatic smell of camphor and essential oils in little balloonlike glands on its leaf surface. As the plant matures, these balloons fill with artemisinin, swell and finally burst, covering the plant with self-made pesticide. In optimal conditions 1 hectare will yield 1-2 tonnes of A. annua leaves. Every tonne gives 2-3kg of artemisinin.

Artemisinin was first isolated in 1972 by scientists working for the Chinese PeopleÕs Liberation Army during the Vietnam War. With thousands of Viet Cong dying from drug-resistant malaria, North VietnamÕs leader Ho Chi Minh turned for help to his Chinese neighbour Mao Zedong. Chinese scientists then extracted the compound artemisinin.

It took years before X-ray crystallographic analysis revealed its molecular structure. The unique compound contained 15 carbon, 23 hydrogen and five oxygen atoms which could be arranged in a multitude of theoretical configurations. Luckily, nature had plumped for a single configuration, allowing the development of more stable molecules and derivatives suitable for pharmaceutical and therapeutic applications.

Artemisinin is used in the synthesis of related compounds in Artemisinin-based Combination Therapies (ACT).

The current commercial ACT is Coartem, a combination of artemether, a derivative of artemisinin and a synthetic substance, lumefantrine. The drug was developed by the pharmaceutical giant Novartis with the Institute for Microbiology and Epidemiology in Beijing, and is recommended by WHO.

Out of 13 African countries that have changed their national policies to require more effective antimalarial treatment, four -- South Africa, Tanzania, Zambia and Burundi -- have adopted ACTs as first-line treatment.
/ENDS