Malaria pv, also called benign tertian malaria, is responsible for more than half of the world’s malaria cases.malaria pv While it usually has a mild course and can be treated with antimalarial drugs, the fact that it persists in moderately endemic areas should make this form of malaria an important focus for research and prevention efforts.malaria pv Despite its benign reputation, severe and even fatal P. vivax can occur in both children and adults.
This is due to the parasite’s ability to relapse after treatment, its resistance to some of the most widely used antimalarial medications and the challenges involved in monitoring this form of malaria.malaria pv Its prevalence in many countries is also driven by a complex interplay between human and mosquito factors, including the presence of various P.malaria pv vivax “strains” with different patterns of relapse, drug resistance and other traits.
Until recently, the global health community generally considered P.malaria pv vivax to be benign and infrequently severe, a status that was supported by trends of declining P.malaria pv falciparum malaria incidence, combined with an increasing recognition that the relapses of P. vivax, the so-called ‘benign tertian malaria’, can cause severe and fatal disease. However, recent evidence of the virulence of this form of malaria has led to a significant shift in knowledge and attitudes towards the species.
This change has come about through the publication of several papers reporting a spectrum of clinical presentations associated with P.malaria pv vivax infection, from the asymptomatic ‘blood stage’ of infection (which can be undiagnosed and may last up to 48 hours) through to the symptoms of severe vivax malaria, which include life-threatening complications like multiorgan dysfunction and death.malaria pv
Blood stage vivax infections are usually diagnosed by the characteristic symptoms of fever with chills, headache, muscle pain (myalgia) and vomiting.malaria pv Symptoms usually begin within 2 hours of a mosquito bite and progress through the Cold stage, which includes shivering and a raised body temperature, followed by a Hot stage with a high fever, a burning sensation, flushed skin, hot breath, thirst and rapid pulse, and finally a Sweating stage with profuse sweating mainly from the head and shoulders. In some patients with severe vivax, convulsions and respiratory failure can occur.
Unlike P.malaria pv falciparum, which can evade reticulocyte clearance by cytoadherence using variant proteins, P. vivax-infected reticulocytes do not adhere to the spleen allowing the parasite to circulate through the liver to relapse in the bloodstream weeks or years later. This undetectable hypnozoite reservoir is one of the primary barriers to malaria elimination and eradication. A better understanding of the role of hypnozoite-specific vir proteins in this process will aid efforts to eliminate this persistent pathogen.