Malaria is a life-threatening disease caused by Plasmodium spp. parasites that are transmitted to people through bites of infected Anopheles mosquitoes. There are at least five species of Plasmodium capable of causing malaria in humans, of which P. falciparum is both the most common and most lethal. Vector control and preventative chemotherapies have been implemented as key measures to reduce the global burden of malaria.
One-third of the world’s population lives at risk of malaria, with young children and pregnant women the most vulnerable. Each year, there are an estimated 250 million cases and 600,000 deaths due to malaria worldwide. Sub-Saharan Africa bears over 95% of the world’s cases and deaths.
Early diagnosis and treatment of malaria is critical for reducing mortality and transmission. Initial presentations of malaria are often nonspecific (fever, chills, sweats, headaches, muscle pains, and nausea), so accurate diagnostics are a vital tool in malaria control. Diagnosis of malaria is classically done under the microscope by studying a suspected patient’s blood smear, where physical evidence of parasites infecting red blood cells can be seen. Supplanting microscopy in many places today are antigen-based rapid diagnostic tests (RDTs). However, in an increasing number of places throughout the world, the parasite has started to evolve away from RDTs through gene deletions of the HRP-2 antigen, the primary target of the current generation of RDTs. In some areas of India and Africa, HRP-2 deletions occur in over 70% of local parasites.
At the same time that the parasite is evolving the means to avoid detection, it continues to develop resistance to modern therapeutics. Antimalarial drug resistance is among one of the greatest threats to global malarial control efforts worldwide, and the development of innovative methods for rapid surveillance is a high priority.