April 25 is World Malaria Day, a date created to highlight the world’s fight against a disease that takes 445,000 lives per year. The year, the WHO called for continued support and greater funding against this infectious disease. In 2016, US$2.7 billion were spent fighting malaria, but the WHO estimates that US$6.5 billion are required per year to successfully address the disease. “Meeting the global malaria targets will only be possible through greater investment and expanded coverage of core tools that prevent, diagnose and treat malaria,” said Pedro Alonso, Director of the Global Malaria Programme.
This mosquito-borne disease is caused by infection from one of five strains of Plasmodium parasites. Of these five, the deadliest is P. falciparum, which most commonly causes fever, headaches and nausea. However, if the disease is left untreated it leads to coma, seizures, organ failure, yellow skin and death. Malaria affected 216 million people in 2016 and, while incidence rate fell between 2010 and 2014, this falling trend reverted last year. In fact, 2016 saw 5 million more cases than the previous year.
While most of malaria cases occur in Africa, the disease has spread to Asia, the Mediterranean and Latin America. In the latter region, prevalence and death from malaria have dropped steadily since 2000 but the disease is still present and responsible for 375,000 cases as of 2014. Mexico is at low risk of malaria, and it is mainly found in the states of Campeche, Chiapas, Chihuahua, Nayarit and Sinaloa. Interestingly, most cases of malaria in Latin America, 77.5 percent, are caused by the parasite P. vivax, which is less deadly than P. falciparum.
Malaria is transmitted by the female Anopheles mosquito. Once in a human host, the P. falciparum parasites move to the liver where they multiply and spread into red blood cells, breed again, destroy the cell and continue to spread to other red blood cells. After repeated cases of malaria, some individuals can develop a “semi-immunity,” where the infection by P. falciparum does not lead to the disease.
And malaria is treatable. Before the 1960s, the disease was commonly treated with quinine or chloroquine, but the emergence of resistant strains of P. falciparium greatly reduced the effectivity of the two medicines and led to many deaths. The disease is now treated with Artemisinin, a drug discovered by Nobel Prize winner Youyou Tu alongside other therapies. However, at this point the most effective measure against malaria is prevention by avoiding the mosquito through the use of insecticide-treated mosquito nets (ITNs).