The Story Behind: Anti-malaria drugs

A new weapon against the malaria pandemic

Over the past centuries, treatment of malaria has grown in leaps and bounds. But there is still no vaccine. And until recently, most medications remained unaffordable for patients in developing countries, where the malaria pandemic is most rampant.

According to the World Health Organisation (WHO), there were an estimated 242 million cases of malaria and 881 000 deaths from the disease worldwide in 2006. Malaria kills one person every 12 seconds, most of them children under 5 years of age. Approximately 86 percent of malaria cases are in Africa, with much of the rest in the India/Pakistan region.

The economic consequences are alarming. Today, the economic burden of malaria to African countries alone is estimated at around $12 billion per year.  

A new hope for countries plagued by malaria arrived in 2001 when Swiss pharmaceutical company Novartis released Coartem, an inexpensive new treatment developed in China. Based on traditional Chinese medicine, the herbal drug is the invention of scientists at the Institute of Microbiology and Epidemiology in Beijing.

An enigmatic enemy

Historically, malaria is one of mankind's oldest enemies. It has followed human migration from Central Africa, where malaria originated, around the world. But until the 19^th century, many facts about malaria, especially its course of infection, remained a mystery.

In 240BC, ancient Greek physician Hippocrates attributed the disease to drinking "stagnant waters" from swamps. The name "malaria" itself is based on a similar misconception, namely that malaria is caused by bad air - Italian "mala aria" - from swamps and marshlands.

The truth took centuries to arrive. In the late 19^th century, scientists were still testing the air and waters of swamps for the origins of malaria. The prime suspect: Swamp-bound bacteria.

French military doctor Alphonse Laveran begged to differ. While stationed in Algeria in 1880, he proved the link between infective female Anopheles mosquitoes and the spread of malaria. As the cause of infection, Laveran identified protozoan parasites of the genus Plasmodium, transmitted to humans by mosquito stings. Laveran received heavy criticism - and ultimately the 1907 Nobel Price for the discovery.

Important puzzle pieces

The link between mosquitoes and malaria marked a new beginning for preventing the disease. Mosquito nets and insecticides became new weapons against malaria at the beginning of the 20^th century. In the year 1900, these measures all but rescued the construction of the Panama Canal, a dramatic failure due to malaria outbreaks for 20 years. 

The discovery of protozoan parasites, now the known enemy, opened the door for research on new malaria treatments. Before, scientists had mostly relied on proven old cures, mainly Quinine. Introduced into Europe in the 1630s by Jesuit missionaries, the toxic plant alkaloid is made from the bark of South American Cinchona trees.  

Malaria research received new impulses (and military funding) during the two world wars, when soldiers stationed in tropical areas were falling ill with malaria by the hundred thousands.

A breakthrough arrived with Chloroquine. The drug was initially discovered in 1934 by German chemist Hans Andersag at Bayer laboratories in Eberfeld, Germany. But due to war turmoil, the drug would not be released until 1946.

A disease of developing countries?

Chloroquine, together with the insecticide DDT, became the major weapon in the WHO's Campaign for the Global Eradication of Malaria, started in 1955.

By the mid-1950s, malaria was banished from North America and most of Europe. However, it remained a pandemic in the tropics and across Africa and India, where it continued to slow down economic progress. 

While patients in developed countries had access to malaria treatments, the Third World suffered from shortages in drug supplies, mainly for financial reasons. The biggest danger of insufficient and irregular supplies, however, is that malaria strains may become resistant to drugs.

Over the next decades, malaria strains in problematic regions became resistant to anti-malarial drugs such as Chloroquine, primaquine and mefloquine. Resistance rates in parts of Africa and Asia climbed to 60-70 percent for certain drugs.

In 1978, the WHO finally reduced its campaign goal from "eradication" of the disease to "control" of its spread. Since then, malaria hot zones have been in dire need of an effective, yet inexpensive treatment that is not resisted by the various malaria strains.

Answers from traditional Chinese medicine

For a new weapon against malaria, Yiquing Zhou and team at the Institute of Microbiology and Epidemiology in Beijing turned to the wisdom of traditional Chinese medicine. After all, malaria had been known in China for over 5 000 years.

The team in Beijing focused on an ancient herb named Artemisia annua, or "Sweet Wormwood". It has been used in China since around 168 BC to treat malaria.

In 1996, Zhou's team used the active ingredient of the herb, artemisinin, to create a new drug in combination with proven anti-malarial substance benflumetol.

The results were astonishing. The new drug controlled malaria-related fevers within 24 to 36 hours. Cure rates range at over 96 percent after only 3-4 days treatment. Best of all, the drug encountered no resistance among malaria strains.

In 2001, Swiss pharmaceutical company Novartis launched the new drug under the name Coartem. It has since been used in more than 160 million malaria treatments around the world, saving an estimated 450 000 lives.

Novartis has been able to reduce the price of Coartem by farming artemisinin in Africa and China.

As a result, Coartem has become more widely available in areas where it is most needed. Artemisinin compounds have also proven effective against other serious diseases, including breast cancer and leukaemia. The compounds are now incorporated into the development of new drugs, also based on time-honoured medical wisdom.