Malaria is a mosquito-borne infectious disease that affects vertebrates and Anopheles mosquitoes. Human malaria causes symptoms that typically include fever, fatigue, vomiting, and headaches. In severe cases, it can cause jaundice, seizures, coma, or death. Symptoms usually begin 10 to 15 days after being bitten by an infected Anopheles mosquito. If not properly treated, people may have recurrences of the disease months later. In those who have recently survived an infection, reinfection usually causes milder symptoms. This partial resistance disappears over months to years if the person has no continuing exposure to malaria. The mosquito vector is itself harmed by Plasmodium infections, causing reduced lifespan.
A blood type is a classification of blood, based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells (RBCs). These antigens may be proteins, carbohydrates, glycoproteins, or glycolipids, depending on the blood group system. Some of these antigens are also present on the surface of other types of cells of various tissues. Several of these red blood cell surface antigens can stem from one allele and collectively form a blood group system.
Anemia or anaemia is a blood disorder in which the blood has a reduced ability to carry oxygen. This can be due to a lower than normal number of red blood cells, a reduction in the amount of hemoglobin available for oxygen transport, or abnormalities in hemoglobin that impair its function.
Blood transfusion is the process of transferring blood products into a person's circulation intravenously. Transfusions are used for various medical conditions to replace lost components of the blood. Early transfusions used whole blood, but modern medical practice commonly uses only components of the blood, such as red blood cells, plasma, platelets, and other clotting factors. White blood cells are transfused only in very rare circumstances, since granulocyte transfusion has limited applications. Whole blood has come back into use in the trauma setting.
Haemophilia A is a blood clotting disorder caused by a genetic deficiency in clotting factor VIII, thereby resulting in significant susceptibility to bleeding, both internally and externally. This condition occurs almost exclusively in males born to carrier mothers due to X-linked recessive inheritance. Nevertheless, rare isolated cases do emerge from de novo (spontaneous) mutations.
Thalassemias are inherited blood disorders that manifest as the production of reduced or zero quantities of hemoglobin. Symptoms depend on the type of thalassemia and can vary from none to severe, including death. Often there is mild to severe anemia as thalassemia can affect the production of red blood cells and also affect how long the red blood cells live. Symptoms of anemia include feeling tired and having pale skin. Other symptoms of thalassemia include bone problems, an enlarged spleen, yellowish skin, pulmonary hypertension, and dark urine. Slow growth may occur in children. Clinically, thalassemia is classed as Transfusion-Dependent Thalassemia (TDT) or non-Transfusion-Dependent Thalassemia (NTDT), since this determines the principal treatment options. TDT requires regular transfusions, typically every two to five weeks. TDTs include Beta-thalassemia major, non-deletional HbH disease, survived Hb Bart's disease, and severe HbE/beta-thalassemia. NTDT does not need regular transfusions but may require transfusion in case of an anemia crisis.
Babesiosis or piroplasmosis is a malaria-like parasitic disease caused by infection with a eukaryotic parasite in the order Piroplasmida, typically a Babesia or Theileria, in the phylum Apicomplexa. Human babesiosis transmission via tick bite is most common in the Northeastern and Midwestern United States and parts of Europe, and sporadic throughout the rest of the world. It occurs in warm weather. People can get infected with Babesia parasites by the bite of an infected tick, by getting a blood transfusion from an infected donor of blood products, or by congenital transmission . Ticks transmit the human strain of babesiosis, so it often presents with other tick-borne illnesses such as Lyme disease. After trypanosomes, Babesia is thought to be the second-most common blood parasite of mammals. They can have major adverse effects on the health of domestic animals in areas without severe winters. In cattle, the disease is known as Texas cattle fever or redwater.
Plasmodium falciparum is a unicellular protozoan parasite of humans, and the deadliest species of Plasmodium that causes malaria in humans. The parasite is transmitted through the bite of a female Anopheles mosquito and causes the disease's most dangerous form, falciparum malaria. P. falciparum is therefore regarded as the deadliest parasite in humans. It is also associated with the development of blood cancer and is classified as a Group 2A (probable) carcinogen.
Artesunate (AS) is a medication used to treat malaria. The intravenous form is preferred to quinine for severe malaria. Often it is used as part of combination therapy, such as artesunate plus mefloquine. It is not used for the prevention of malaria. Artesunate can be given by injection into a vein, injection into a muscle, by mouth, and by rectum.
Atovaquone, sold under the brand name Mepron, is an antimicrobial medication for the prevention and treatment of Pneumocystis jirovecii pneumonia (PCP).
Beta thalassemias are a group of inherited blood disorders. They are forms of thalassemia caused by reduced or absent synthesis of the beta chains of hemoglobin that result in variable outcomes ranging from severe anemia to clinically asymptomatic individuals. Global annual incidence is estimated at one in 100,000. Beta thalassemias occur due to malfunctions in the hemoglobin subunit beta or HBB. The severity of the disease depends on the nature of the mutation.
Epoetin alfa, sold under the brand name Epogen among others, is a human erythropoietin produced in cell culture using recombinant DNA technology. Epoetin alfa is an erythropoiesis-stimulating agent. It stimulates erythropoiesis and is used to treat anemia, commonly associated with chronic kidney failure and cancer chemotherapy. Epoetin alfa is developed by Amgen.
Malaria prophylaxis is the preventive treatment of malaria. Several malaria vaccines are under development.
Malaria vaccines are vaccines that prevent malaria, a mosquito-borne infectious disease which affected an estimated 249 million people globally in 85 malaria-endemic countries and areas and caused 608,000 deaths in 2022. The first approved vaccine for malaria is RTS,S, known by the brand name Mosquirix. As of April 2023, the vaccine has been given to 1.5 million children living in areas with moderate-to-high malaria transmission. It requires at least three doses in infants by age 2, and a fourth dose extends the protection for another 1–2 years. The vaccine reduces hospital admissions from severe malaria by around 30%.
Sickle cell disease (SCD), also simply called sickle cell, is a group of hemoglobin-related blood disorders that are typically inherited. The most common type is known as sickle cell anemia. Sickle cell anemia results in an abnormality in the oxygen-carrying protein haemoglobin found in red blood cells. This leads to the red blood cells adopting an abnormal sickle-like shape under certain circumstances; with this shape, they are unable to deform as they pass through capillaries, causing blockages. Problems in sickle cell disease typically begin around 5 to 6 months of age. A number of health problems may develop, such as attacks of pain in joints, anemia, swelling in the hands and feet, bacterial infections, dizziness and stroke. The probability of severe symptoms, including long-term pain, increases with age. Without treatment, people with SCD rarely reach adulthood but with good healthcare, median life expectancy is between 58 and 66 years. All of the major organs are affected by sickle cell disease. The liver, heart, kidneys, gallbladder, eyes, bones, and joints can be damaged from the abnormal functions of the sickle cells and their inability to effectively flow through the small blood vessels.
Disease resistance is the ability to prevent or reduce the presence of diseases in otherwise susceptible hosts. It can arise from genetic or environmental factors, such as incomplete penetrance. Disease tolerance is different as it is the ability of a host to limit the impact of disease on host health.
RTS,S/AS01 is a recombinant protein-based malaria vaccine. It is one of two malaria vaccines approved. As of April 2022, the vaccine has been given to 1 million children living in areas with moderate-to-high malaria transmission, with millions more doses to be provided as the vaccine's production expands. 18 million doses have been allocated for 2023-2025. It requires at least three doses in infants by age 2, with a fourth dose extending the protection for another 1–2 years. The vaccine reduces hospital admissions from severe malaria by around 30% and reduces toddler deaths by 15%.
Moses R Kamya, is a Ugandan physician, academic, researcher and academic administrator, who serves as Professor and Chair of the Department Medicine, Makerere University School of Medicine, a component of Makerere University College of Health Sciences.
Sanjeev Krishna,, is a British physician and parasitologist whose research focuses on affordable diagnosis and treatment of diseases such as COVID-19, malaria, Ebola, African trypanosomiasis, leishmaniasis, and colorectal cancer. Krishna is Professor of Medicine and Molecular Parasitology at St George's, University of London and St George's Hospital.
Sherrill Slichter is an American physician whose work on platelet biology earned her transfusion medicine’s three highest honors: the AABB Karl Landsteiner Memorial Award; International Society of Blood Transfusion Presidential Award; and the British Blood Transfusion Society James Blundell Award.
