Malaria in Africa: parasite 'resistant to artemisinin.' Scientists have raised an alarm about a newly observed resistance to artemisinin, a crucial drug used as monotherapy or as the core component of combination therapies in the treatment of malaria. A recent study published online August 3 in Nature Medicine found that samples of Plasmodium parasites collected from six sites in Rwanda resisted treatment with artemisinin, both as monotherapy and as combination therapy. Resistance to artemisinin is widespread in Southeast Asia but until now its efficacy was high outside of that region. The researchers state that the existence of artemisinin resistance in Africa constitutes a "major public health threat" for the continent. According to the World Health Organization, there were about 228 million cases of malaria in 2018 and 405,000 deaths, with over 90% of them on the African continent and 67% among children under the age of five. Scientists fear that resistant parasites will spread throughout Africa, as happened in 1980 when chloroquine lost efficacy, resulting in the death of millions of African children.