By Stephanie Nebehay GENEVA | Wed Jan 12, 2011 5:49am EST GENEVA (Reuters) - The World Health Organization launched a plan on Wednesday to stop a form of drug-resistant malaria from spreading from Southeast Asia to Africa, where millions of lives could be at risk. It would cost about $175 million a year to contain and prevent the global spread of the artemisinin-resistant parasite which first emerged along the Thai-Cambodian border in 2007, the United Nations agency said. Artemisinin, derived from sweet wormwood, or the Artemisia annua plant, is the most potent drug available against malaria, especially when used in artemisinin combination therapy (ACT), which links it with other drugs. The resistant -- and therefore longer-to-treat -- form of malaria is already suspected of breaking out along the Thai-Myanmar border and in a province of Vietnam, where tests are underway to confirm it, but the great fear is of it breaking out across Africa. "There is a finite window of opportunity to contain artemisinin resistance before it spreads," the WHO warned in a report, "Global Plan for Artemisinin Resistance Containment". Resistance to previous generations of anti-malarial drugs spread rapidly from the same Mekong region to India and then Africa, resulting in many deaths, according to the WHO strategy, drawn up by 100 global experts. Malaria infects about 243 million people worldwide a year, causing an estimated 863,000 deaths, making it a major killer especially among African children. "The urgency is increased by the fact that no other antimalarial medicines are available that offer the same levels of efficacy and tolerability as ACTs, and few promising alternatives are available in the immediate research and development pipeline," the WHO report said. The $175 million being sought for containment would include some $65 million for accelerating research and development of new antimalarial drugs which are not based on artemisinin. Overall, some $3 billion is spent annually on malaria control. The rest of the funds would be used to step up monitoring of the disease and purchase diagnostic kits to detect the resistant form. Swiss drugmaker Novartis and Sanofi-Aventis of France make the most widely-used ACTs, which treat 80 million and 45 million patients respectively per year, according to the Geneva-based Medicines for Malaria Venture. The looming threat follows a decade in which the number of malaria cases was halved in 43 countries, according to WHO. The agency has said the world could stop malaria deaths by 2015 if massive investment was made to ramp up control measures, including wider use of insecticide-treated mosquito nets. NB Tanzania through the MOH need a close look to watch strain of malaria that has become resistant to Artemisinin to do not get free entrance into the country-- the best drug available to fight the disease.