Malaria: A protozoan disease caused in humans by four species of the PLASMODIUM genus: PLASMODIUM FALCIPARUM; PLASMODIUM VIVAX; PLASMODIUM OVALE; and PLASMODIUM MALARIAE; and transmitted by the bite of an infected female mosquito of the genus ANOPHELES. Malaria is endemic in parts of Asia, Africa, Central and South America, Oceania, and certain Caribbean islands. It is characterized by extreme exhaustion associated with paroxysms of high FEVER; SWEATING; shaking CHILLS; and ANEMIA. Malaria in ANIMALS is caused by other species of plasmodia.Malaria, Falciparum: Malaria caused by PLASMODIUM FALCIPARUM. This is the severest form of malaria and is associated with the highest levels of parasites in the blood. This disease is characterized by irregularly recurring febrile paroxysms that in extreme cases occur with acute cerebral, renal, or gastrointestinal manifestations.Plasmodium falciparum: A species of protozoa that is the causal agent of falciparum malaria (MALARIA, FALCIPARUM). It is most prevalent in the tropics and subtropics.Malaria, Vivax: Malaria caused by PLASMODIUM VIVAX. This form of malaria is less severe than MALARIA, FALCIPARUM, but there is a higher probability for relapses to occur. Febrile paroxysms often occur every other day.Protozoan Proteins: Proteins found in any species of protozoan.Malaria, Cerebral: A condition characterized by somnolence or coma in the presence of an acute infection with PLASMODIUM FALCIPARUM (and rarely other Plasmodium species). Initial clinical manifestations include HEADACHES; SEIZURES; and alterations of mentation followed by a rapid progression to COMA. Pathologic features include cerebral capillaries filled with parasitized erythrocytes and multiple small foci of cortical and subcortical necrosis. (From Adams et al., Principles of Neurology, 6th ed, p136)Malaria Vaccines: Vaccines made from antigens arising from any of the four strains of Plasmodium which cause malaria in humans, or from P. berghei which causes malaria in rodents.Antigens, Protozoan: Any part or derivative of any protozoan that elicits immunity; malaria (Plasmodium) and trypanosome antigens are presently the most frequently encountered.Chloroquine: The prototypical antimalarial agent with a mechanism that is not well understood. It has also been used to treat rheumatoid arthritis, systemic lupus erythematosus, and in the systemic therapy of amebic liver abscesses.Plasmodium: A genus of protozoa that comprise the malaria parasites of mammals. Four species infect humans (although occasional infections with primate malarias may occur). These are PLASMODIUM FALCIPARUM; PLASMODIUM MALARIAE; PLASMODIUM OVALE, and PLASMODIUM VIVAX. Species causing infection in vertebrates other than man include: PLASMODIUM BERGHEI; PLASMODIUM CHABAUDI; P. vinckei, and PLASMODIUM YOELII in rodents; P. brasilianum, PLASMODIUM CYNOMOLGI; and PLASMODIUM KNOWLESI in monkeys; and PLASMODIUM GALLINACEUM in chickens.Plasmodium vivax: A protozoan parasite that causes vivax malaria (MALARIA, VIVAX). This species is found almost everywhere malaria is endemic and is the only one that has a range extending into the temperate regions.Anopheles: A genus of mosquitoes (CULICIDAE) that are known vectors of MALARIA.Antimalarials: Agents used in the treatment of malaria. They are usually classified on the basis of their action against plasmodia at different stages in their life cycle in the human. (From AMA, Drug Evaluations Annual, 1992, p1585)Antibodies, Protozoan: Immunoglobulins produced in a response to PROTOZOAN ANTIGENS.Drug Resistance: Diminished or failed response of an organism, disease or tissue to the intended effectiveness of a chemical or drug. It should be differentiated from DRUG TOLERANCE which is the progressive diminution of the susceptibility of a human or animal to the effects of a drug, as a result of continued administration.Pyrimethamine: One of the FOLIC ACID ANTAGONISTS that is used as an antimalarial or with a sulfonamide to treat toxoplasmosis.Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Sulfadoxine: A long acting sulfonamide that is used, usually in combination with other drugs, for respiratory, urinary tract, and malarial infections.DNA, Protozoan: Deoxyribonucleic acid that makes up the genetic material of protozoa.Parasitic Sensitivity Tests: Tests that demonstrate the relative effectiveness of chemotherapeutic agents against specific parasites.Drug Combinations: Single preparations containing two or more active agents, for the purpose of their concurrent administration as a fixed dose mixture.Quinine: An alkaloid derived from the bark of the cinchona tree. It is used as an antimalarial drug, and is the active ingredient in extracts of the cinchona that have been used for that purpose since before 1633. Quinine is also a mild antipyretic and analgesic and has been used in common cold preparations for that purpose. It was used commonly and as a bitter and flavoring agent, and is still useful for the treatment of babesiosis. Quinine is also useful in some muscular disorders, especially nocturnal leg cramps and myotonia congenita, because of its direct effects on muscle membrane and sodium channels. The mechanisms of its antimalarial effects are not well understood.Artemisinins: A group of SESQUITERPENES and their analogs that contain a peroxide group (PEROXIDES) within an oxepin ring (OXEPINS).Parasitemia: The presence of parasites (especially malarial parasites) in the blood. (Dorland, 27th ed)Pregnancy Complications, Parasitic: The co-occurrence of pregnancy and parasitic diseases. The parasitic infection may precede or follow FERTILIZATION.Endemic Diseases: The constant presence of diseases or infectious agents within a given geographic area or population group. It may also refer to the usual prevalence of a given disease with such area or group. It includes holoendemic and hyperendemic diseases. A holoendemic disease is one for which a high prevalent level of infection begins early in life and affects most of the child population, leading to a state of equilibrium such that the adult population shows evidence of the disease much less commonly than do children (malaria in many communities is a holoendemic disease). A hyperendemic disease is one that is constantly present at a high incidence and/or prevalence rate and affects all groups equally. (Last, A Dictionary of Epidemiology, 3d ed, p53, 78, 80)Kenya: A republic in eastern Africa, south of ETHIOPIA, west of SOMALIA with TANZANIA to its south, and coastline on the Indian Ocean. Its capital is Nairobi.Plasmodium berghei: A protozoan parasite of rodents transmitted by the mosquito Anopheles dureni.Mosquito Control: The reduction or regulation of the population of mosquitoes through chemical, biological, or other means.Insect Vectors: Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Genes, Protozoan: The functional hereditary units of protozoa.SesquiterpenesAmodiaquine: A 4-aminoquinoline compound with anti-inflammatory properties.Gabon: A republic in west equatorial Africa, south of CAMEROON and west of the CONGO. Its capital is Libreville.Travel: Aspects of health and disease related to travel.Papua New Guinea: A country consisting of the eastern half of the island of New Guinea and adjacent islands, including New Britain, New Ireland, the Admiralty Islands, and New Hanover in the Bismarck Archipelago; Bougainville and Buka in the northern Solomon Islands; the D'Entrecasteaux and Trobriand Islands; Woodlark (Murua) Island; and the Louisiade Archipelago. It became independent on September 16, 1975. Formerly, the southern part was the Australian Territory of Papua, and the northern part was the UN Trust Territory of New Guinea, administered by Australia. They were administratively merged in 1949 and named Papua and New Guinea, and renamed Papua New Guinea in 1971.Plasmodium malariae: A protozoan parasite that occurs primarily in subtropical and temperate areas. It is the causal agent of quartan malaria. As the parasite grows it exhibits little ameboid activity.Senegal: A republic in western Africa, southwest of MAURITANIA and east of MALI. Its capital is Dakar.Tanzania: A republic in eastern Africa, south of UGANDA and north of MOZAMBIQUE. Its capital is Dar es Salaam. It was formed in 1964 by a merger of the countries of TANGANYIKA and ZANZIBAR.Microscopy: The use of instrumentation and techniques for visualizing material and details that cannot be seen by the unaided eye. It is usually done by enlarging images, transmitted by light or electron beams, with optical or magnetic lenses that magnify the entire image field. With scanning microscopy, images are generated by collecting output from the specimen in a point-by-point fashion, on a magnified scale, as it is scanned by a narrow beam of light or electrons, a laser, a conductive probe, or a topographical probe.Thailand: Formerly known as Siam, this is a Southeast Asian nation at the center of the Indochina peninsula. Bangkok is the capital city.Primaquine: An aminoquinoline that is given by mouth to produce a radical cure and prevent relapse of vivax and ovale malarias following treatment with a blood schizontocide. It has also been used to prevent transmission of falciparum malaria by those returning to areas where there is a potential for re-introduction of malaria. Adverse effects include anemias and GI disturbances. (From Martindale, The Extra Pharmacopeia, 30th ed, p404)Malaria, Avian: Any of a group of infections of fowl caused by protozoa of the genera PLASMODIUM, Leucocytozoon, and Haemoproteus. The life cycles of these parasites and the disease produced bears strong resemblance to those observed in human malaria.AfricaParasitology: The study of parasites and PARASITIC DISEASES.Ethanolamines: AMINO ALCOHOLS containing the ETHANOLAMINE; (-NH2CH2CHOH) group and its derivatives.Ghana: A republic in western Africa, south of BURKINA FASO and west of TOGO. Its capital is Accra.Schizonts: Multinucleate cells or a stage in the development of sporozoan protozoa. It is exemplified by the life cycle of PLASMODIUM FALCIPARUM in the MALARIA infection cycle.Host-Parasite Interactions: The relationship between an invertebrate and another organism (the host), one of which lives at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Anopheles gambiae: A species of mosquito in the genus Anopheles and the principle vector of MALARIA in Africa.Sporozoites: The product of meiotic division of zygotes in parasitic protozoa comprising haploid cells. These infective cells invade the host and undergo asexual reproduction producing MEROZOITES (or other forms) and ultimately gametocytes.Culicidae: A family of the order DIPTERA that comprises the mosquitoes. The larval stages are aquatic, and the adults can be recognized by the characteristic WINGS, ANIMAL venation, the scales along the wing veins, and the long proboscis. Many species are of particular medical importance.Genome, Protozoan: The complete genetic complement contained in a set of CHROMOSOMES in a protozoan.Plasmodium yoelii: A species of PLASMODIUM causing malaria in rodents.Cameroon: A republic in central Africa lying east of CHAD and the CENTRAL AFRICAN REPUBLIC and west of NIGERIA. The capital is Yaounde.Burkina Faso: A republic in western Africa, south and east of MALI and west of NIGER. Its capital is Ouagadougou. It was formerly called Upper Volta until 1984.Life Cycle Stages: The continuous sequence of changes undergone by living organisms during the post-embryonic developmental process, such as metamorphosis in insects and amphibians. This includes the developmental stages of apicomplexans such as the malarial parasite, PLASMODIUM FALCIPARUM.Insecticides: Pesticides designed to control insects that are harmful to man. The insects may be directly harmful, as those acting as disease vectors, or indirectly harmful, as destroyers of crops, food products, or textile fabrics.Parasite Load: Measure of the number of the PARASITES present in a host organism.Mozambique: A republic in southern Africa, south of TANZANIA, east of ZAMBIA and ZIMBABWE, bordered on the west by the Indian Ocean. Its capital is Maputo. It was formerly called Portuguese East Africa.Gambia: A republic in western Africa, constituting an enclave within SENEGAL extending on both sides of the Gambia River. Its capital is Banjul, formerly Bathurst.CambodiaBedding and Linens: Articles of cloth, usually cotton or rayon and other synthetic or cotton-blend fabrics, used in households, hospitals, physicians' examining rooms, nursing homes, etc., for sheets, pillow cases, toweling, gowns, drapes, and the like.Insect Bites and Stings: Bites and stings inflicted by insects.Fluorenes: A family of diphenylenemethane derivatives.Insecticide-Treated Bednets: Lightweight meshwork fabric made of cotton, silk, polyester, nylon (polyamides), or other material impregnated with insecticide, having openings too small to allow entry of mosquitoes or other insects, thereby offering protection against insect bite and insect-borne diseases.Trophozoites: Cells or feeding stage in the life cycle of sporozoan protozoa. In the malarial parasite, the trophozoite develops from the MEROZOITE and then splits into the SCHIZONT. Trophozoites that are left over from cell division can go on to form gametocytes.Indonesia: A republic stretching from the Indian Ocean east to New Guinea, comprising six main islands: Java, Sumatra, Bali, Kalimantan (the Indonesian portion of the island of Borneo), Sulawesi (formerly known as the Celebes) and Irian Jaya (the western part of New Guinea). Its capital is Djakarta. The ethnic groups living there are largely Chinese, Arab, Eurasian, Indian, and Pakistani; 85% of the peoples are of the Islamic faith.Seasons: Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Tetrahydrofolate Dehydrogenase: An enzyme of the oxidoreductase class that catalyzes the reaction 7,8-dihyrofolate and NADPH to yield 5,6,7,8-tetrahydrofolate and NADPH+, producing reduced folate for amino acid metabolism, purine ring synthesis, and the formation of deoxythymidine monophosphate. Methotrexate and other folic acid antagonists used as chemotherapeutic drugs act by inhibiting this enzyme. (Dorland, 27th ed) EC 1.5.1.3.Polymerase Chain Reaction: In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.Blood: The body fluid that circulates in the vascular system (BLOOD VESSELS). Whole blood includes PLASMA and BLOOD CELLS.Anemia: A reduction in the number of circulating ERYTHROCYTES or in the quantity of HEMOGLOBIN.Parasites: Invertebrate organisms that live on or in another organism (the host), and benefit at the expense of the other. Traditionally excluded from definition of parasites are pathogenic BACTERIA; FUNGI; VIRUSES; and PLANTS; though they may live parasitically.Plasmodium chabaudi: A protozoan parasite of rodents transmitted by the mosquito Anopheles stephensi.Plasmodium ovale: A species of protozoan parasite causing MALARIA. It is the rarest of the four species of PLASMODIUM infecting humans, but is common in West African countries and neighboring areas.Dihydropteroate Synthase: An enzyme that catalyzes the formation of dihydropteroate from p-aminobenzoic acid and dihydropteridine-hydroxymethyl-pyrophosphate. EC 2.5.1.15.Mali: A country in western Africa, east of MAURITANIA and south of ALGERIA. Its capital is Bamako. From 1904-1920 it was known as Upper Senegal-Niger; prior to 1958, as French Sudan; 1958-1960 as the Sudanese Republic and 1959-1960 it joined Senegal in the Mali Federation. It became an independent republic in 1960.Uganda: A republic in eastern Africa, south of SUDAN and west of KENYA. Its capital is Kampala.Sudan: A country in northeastern Africa. The capital is Khartoum.Mosquito Nets: Free-standing or supported lightweight meshwork fabric made of cotton, silk, polyester or other material, having openings too small to allow entry of mosquitoes or other insects, thereby protecting against INSECT BITES; INSECT STINGS, and insect-borne diseases.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Placenta Diseases: Pathological processes or abnormal functions of the PLACENTA.Myanmar: A republic of southeast Asia, northwest of Thailand, long familiar as Burma. Its capital is Yangon, formerly Rangoon. Inhabited by people of Mongolian stock and probably of Tibetan origin, by the 3d century A.D. it was settled by Hindus. The modern Burmese state was founded in the 18th century but was in conflict with the British during the 19th century. Made a crown colony of Great Britain in 1937, it was granted independence in 1947. In 1989 it became Myanmar. The name comes from myanma, meaning the strong, as applied to the Burmese people themselves. (From Webster's New Geographical Dictionary, 1988, p192 & Room, Brewer's Dictionary of Names, 1992, p367)Diagnostic Tests, Routine: Diagnostic procedures, such as laboratory tests and x-rays, routinely performed on all individuals or specified categories of individuals in a specified situation, e.g., patients being admitted to the hospital. These include routine tests administered to neonates.Inhibitory Concentration 50: The concentration of a compound needed to reduce population growth of organisms, including eukaryotic cells, by 50% in vitro. Though often expressed to denote in vitro antibacterial activity, it is also used as a benchmark for cytotoxicity to eukaryotic cells in culture.Drug Therapy, Combination: Therapy with two or more separate preparations given for a combined effect.Malawi: A republic in southern Africa east of ZAMBIA and MOZAMBIQUE. Its capital is Lilongwe. It was formerly called Nyasaland.Benin: A republic in western Africa, south of NIGER and between TOGO and NIGERIA. Its capital is Porto-Novo. It was formerly called Dahomey. In the 17th century it was a kingdom in the southern area of Africa. Coastal footholds were established by the French who deposed the ruler by 1892. It was made a French colony in 1894 and gained independence in 1960. Benin comes from the name of the indigenous inhabitants, the Bini, now more closely linked with southern Nigeria (Benin City, a town there). Bini may be related to the Arabic bani, sons. (From Webster's New Geographical Dictionary, 1988, p136, 310 & Room, Brewer's Dictionary of Names, 1992, p60)Plasmodium knowlesi: A protozoan parasite from Southeast Asia that causes monkey malaria. It is naturally acquired by man in Malaysia and can also be transmitted experimentally to humans.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Nigeria: A republic in western Africa, south of NIGER between BENIN and CAMEROON. Its capital is Abuja.Mefloquine: A phospholipid-interacting antimalarial drug (ANTIMALARIALS). It is very effective against PLASMODIUM FALCIPARUM with very few side effects.French Guiana: A French overseas department on the northeast coast of South America. Its capital is Cayenne. It was first settled by the French in 1604. Early development was hindered because of the presence of a penal colony. The name of the country and the capital are variants of Guyana, possibly from the native Indian Guarani guai (born) + ana (kin), implying a united and interrelated race of people. (From Webster's New Geographical Dictionary, 1988, p418 & Room, Brewer's Dictionary of Names, 1992, p195)Fever: An abnormal elevation of body temperature, usually as a result of a pathologic process.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.RNA, Protozoan: Ribonucleic acid in protozoa having regulatory and catalytic roles as well as involvement in protein synthesis.Disease Vectors: Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.Disease Eradication: Termination of all transmission of infection by global extermination of the infectious agent through surveillance and containment (From Porta, A Dictionary of Epidemiology, 5th ed).ColombiaInfant, Newborn: An infant during the first month after birth.Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Melanesia: The collective name for the islands of the Pacific Ocean northeast of Australia, including NEW CALEDONIA; VANUATU; New Hebrides, Solomon Islands, Admiralty Islands, Bismarck Archipelago, FIJI, etc. Melanesia (from the Greek melas, black + nesos, island) is so called from the black color of the natives who are generally considered to be descended originally from the Negroid Papuans and the Polynesians or Malays. (From Webster's New Geographical Dictionary, 1988, p748 & Room, Brewer's Dictionary of Names, 1992, p344)Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Geography: The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)Rain: Water particles that fall from the ATMOSPHERE.Rural Population: The inhabitants of rural areas or of small towns classified as rural.Ethiopia: An independent state in eastern Africa. Ethiopia is located in the Horn of Africa and is bordered on the north and northeast by Eritrea, on the east by Djibouti and Somalia, on the south by Kenya, and on the west and southwest by Sudan. Its capital is Addis Ababa.Africa South of the Sahara: All of Africa except Northern Africa (AFRICA, NORTHERN).Angola: A republic in southern Africa, southwest of DEMOCRATIC REPUBLIC OF THE CONGO and west of ZAMBIA. Its capital is Luanda.Chemoprevention: The use of chemical compounds to prevent the development of a specific disease.IndiaGenotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Membrane Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.Sickle Cell Trait: The condition of being heterozygous for hemoglobin S.Pyrethrins: The active insecticidal constituent of CHRYSANTHEMUM CINERARIIFOLIUM flowers. Pyrethrin I is the pyretholone ester of chrysanthemummonocarboxylic acid and pyrethrin II is the pyretholone ester of chrysanthemumdicarboxylic acid monomethyl ester.Oocysts: Zygote-containing cysts of sporozoan protozoa. Further development in an oocyst produces small individual infective organisms called SPOROZOITES. Then, depending on the genus, the entire oocyst is called a sporocyst or the oocyst contains multiple sporocysts encapsulating the sporozoites.Vanuatu: A republic consisting of an island group in Melanesia, in the southwest Pacific Ocean. Its capital is Port-Vila. It was called New Hebrides until 1980. It was discovered in 1606 by the Portuguese, forgotten for 160 years, then visited by Bougainville in 1768 and Captain Cook in 1774. It was under joint British and French administration from 1906 until it became independent in 1980 under the name of Vanuatu. The name is native, meaning our land. (From Webster's New Geographical Dictionary, 1988, p833 & Room, Brewer's Dictionary of Names, 1992, p570)Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Topography, Medical: The systematic surveying, mapping, charting, and description of specific geographical sites, with reference to the physical features that were presumed to influence health and disease. Medical topography should be differentiated from EPIDEMIOLOGY in that the former emphasizes geography whereas the latter emphasizes disease outbreaks.Aotidae: A family of the New World monkeys inhabiting the forests of South and Central America. There is a single genus and several species occurring in this family, including AOTUS TRIVIRGATUS (Northern night monkeys).Hemeproteins: Proteins that contain an iron-porphyrin, or heme, prosthetic group resembling that of hemoglobin. (From Lehninger, Principles of Biochemistry, 1982, p480)Sensitivity and Specificity: Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)Zambia: A republic in southern Africa, south of DEMOCRATIC REPUBLIC OF THE CONGO and TANZANIA, and north of ZIMBABWE. Its capital is Lusaka. It was formerly called Northern Rhodesia.VietnamSulfanilamides: Compounds based on 4-aminobenzenesulfonamide. The '-anil-' part of the name refers to aniline.Merozoite Surface Protein 1: A surface protein found on Plasmodium species which induces a T-cell response. The antigen is polymorphic, sharing amino acid sequence homology among PLASMODIUM FALCIPARUM; PLASMODIUM CHABAUDI; PLASMODIUM VIVAX; and PLASMODIUM YOELII.DDT: A polychlorinated pesticide that is resistant to destruction by light and oxidation. Its unusual stability has resulted in difficulties in residue removal from water, soil, and foodstuffs. This substance may reasonably be anticipated to be a carcinogen: Fourth Annual Report on Carcinogens (NTP-85-002, 1985). (From Merck Index, 11th ed)Congo: A republic in central Africa lying between GABON and DEMOCRATIC REPUBLIC OF THE CONGO and south of Cameroon. Its capital is Brazzaville.Antigenic Variation: Change in the surface ANTIGEN of a microorganism. There are two different types. One is a phenomenon, especially associated with INFLUENZA VIRUSES, where they undergo spontaneous variation both as slow antigenic drift and sudden emergence of new strains (antigenic shift). The second type is when certain PARASITES, especially trypanosomes, PLASMODIUM, and BORRELIA, survive the immune response of the host by changing the surface coat (antigen switching). (From Herbert et al., The Dictionary of Immunology, 4th ed)Incidence: The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.Reagent Kits, Diagnostic: Commercially prepared reagent sets, with accessory devices, containing all of the major components and literature necessary to perform one or more designated diagnostic tests or procedures. They may be for laboratory or personal use.Polymorphism, Genetic: The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.PeruInsecticide Resistance: The development by insects of resistance to insecticides.Folic Acid Antagonists: Inhibitors of the enzyme, dihydrofolate reductase (TETRAHYDROFOLATE DEHYDROGENASE), which converts dihydrofolate (FH2) to tetrahydrofolate (FH4). They are frequently used in cancer chemotherapy. (From AMA, Drug Evaluations Annual, 1994, p2033)Entomology: A discipline or occupation concerned with the study of INSECTS, including the biology and the control of insects.Equatorial Guinea: A republic in central Africa, bordering the Bay of Biafra, CAMEROON is to the north and GABON to the south. Its capital is Malabo.Erythrocyte Membrane: The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.Burundi: A republic in eastern Africa bounded on the north by RWANDA and on the south by TANZANIA. Its capital is Bujumbura.Africa, Western: The geographical area of Africa comprising BENIN; BURKINA FASO; COTE D'IVOIRE; GAMBIA; GHANA; GUINEA; GUINEA-BISSAU; LIBERIA; MALI; MAURITANIA; NIGER; NIGERIA; SENEGAL; SIERRA LEONE; and TOGO.Hemoglobins: The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.Climate: The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)LaosAlleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Gametogenesis: The process of germ cell development from the primordial GERM CELLS to the mature haploid GAMETES: ova in the female (OOGENESIS) or sperm in the male (SPERMATOGENESIS).Multidrug Resistance-Associated Proteins: A sequence-related subfamily of ATP-BINDING CASSETTE TRANSPORTERS that actively transport organic substrates. Although considered organic anion transporters, a subset of proteins in this family have also been shown to convey drug resistance to neutral organic drugs. Their cellular function may have clinical significance for CHEMOTHERAPY in that they transport a variety of ANTINEOPLASTIC AGENTS. Overexpression of proteins in this class by NEOPLASMS is considered a possible mechanism in the development of multidrug resistance (DRUG RESISTANCE, MULTIPLE). Although similar in function to P-GLYCOPROTEINS, the proteins in this class share little sequence homology to the p-glycoprotein family of proteins.Genetic Variation: Genotypic differences observed among individuals in a population.Asymptomatic Infections: Infections that do not exhibit symptoms.Glycophorin: The major sialoglycoprotein of the human erythrocyte membrane. It consists of at least two sialoglycopeptides and is composed of 60% carbohydrate including sialic acid and 40% protein. It is involved in a number of different biological activities including the binding of MN blood groups, influenza viruses, kidney bean phytohemagglutinin, and wheat germ agglutinin.Asia, Southeastern: The geographical area of Asia comprising BORNEO; BRUNEI; CAMBODIA; INDONESIA; LAOS; MALAYSIA; the MEKONG VALLEY; MYANMAR (formerly Burma), the PHILIPPINES; SINGAPORE; THAILAND; and VIETNAM.Cote d'Ivoire: A republic in western Africa, south of MALI and BURKINA FASO, bordered by GHANA on the east. Its administrative capital is Abidjan and Yamoussoukro has been the official capital since 1983. The country was formerly called Ivory Coast.Time Factors: Elements of limited time intervals, contributing to particular results or situations.alpha-Thalassemia: A disorder characterized by reduced synthesis of the alpha chains of hemoglobin. The severity of this condition can vary from mild anemia to death, depending on the number of genes deleted.Apicomplexa: A phylum of unicellular parasitic EUKARYOTES characterized by the presence of complex apical organelles generally consisting of a conoid that aids in penetrating host cells, rhoptries that possibly secrete a proteolytic enzyme, and subpellicular microtubules that may be related to motility.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Placenta: A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).Drug Resistance, Multiple: Simultaneous resistance to several structurally and functionally distinct drugs.Dapsone: A sulfone active against a wide range of bacteria but mainly employed for its actions against MYCOBACTERIUM LEPRAE. Its mechanism of action is probably similar to that of the SULFONAMIDES which involves inhibition of folic acid synthesis in susceptible organisms. It is also used with PYRIMETHAMINE in the treatment of malaria. (From Martindale, The Extra Pharmacopoeia, 30th ed, p157-8)Permethrin: A pyrethroid insecticide commonly used in the treatment of LICE INFESTATIONS and SCABIES.Aminoquinolines: Quinolines substituted in any position by one or more amino groups.Vaccines, Synthetic: Small synthetic peptides that mimic surface antigens of pathogens and are immunogenic, or vaccines manufactured with the aid of recombinant DNA techniques. The latter vaccines may also be whole viruses whose nucleic acids have been modified.Glucosephosphate Dehydrogenase Deficiency: A disease-producing enzyme deficiency subject to many variants, some of which cause a deficiency of GLUCOSE-6-PHOSPHATE DEHYDROGENASE activity in erythrocytes, leading to hemolytic anemia.Liberia: A republic in western Africa, south of GUINEA and east of COTE D'IVOIRE. Its capital is Monrovia.Rural Health: The status of health in rural populations.New Guinea: Originally an island of the Malay Archipelago, the second largest island in the world. It divided, West New Guinea becoming part of Indonesia and East New Guinea becoming Papua New Guinea.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Communicable Disease Control: Programs of surveillance designed to prevent the transmission of disease by any means from person to person or from animal to man.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Pregnancy Complications, Infectious: The co-occurrence of pregnancy and an INFECTION. The infection may precede or follow FERTILIZATION.Coinfection: Simultaneous infection of a host organism by two or more pathogens. In virology, coinfection commonly refers to simultaneous infection of a single cell by two or more different viruses.Coma: A profound state of unconsciousness associated with depressed cerebral activity from which the individual cannot be aroused. Coma generally occurs when there is dysfunction or injury involving both cerebral hemispheres or the brain stem RETICULAR FORMATION.Gravidity: The number of pregnancies, complete or incomplete, experienced by a female. It is different from PARITY, which is the number of offspring borne. (From Stedman, 26th ed)Recombinant Proteins: Proteins prepared by recombinant DNA technology.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Democratic Republic of the Congo: A republic in central Africa, east of the REPUBLIC OF THE CONGO, south of the CENTRAL AFRICAN REPUBLIC and north of ANGOLA and ZAMBIA. The capital is Kinshasa.PhenanthrenesCytochromes b: Cytochromes of the b group that have alpha-band absorption of 563-564 nm. They occur as subunits in MITOCHONDRIAL ELECTRON TRANSPORT COMPLEX III.Antigens, Surface: Antigens on surfaces of cells, including infectious or foreign cells or viruses. They are usually protein-containing groups on cell membranes or walls and may be isolated.Sri LankaBrazilSierra Leone: A republic in western Africa, south of GUINEA and west of LIBERIA. Its capital is Freetown.HondurasSulfalene: Long-acting plasma-bound sulfonamide used for respiratory and urinary tract infections and also for malaria.Treatment Failure: A measure of the quality of health care by assessment of unsuccessful results of management and procedures used in combating disease, in individual cases or series.Mauritania: A republic in western Africa, southwest of ALGERIA and west of MALI. Its capital is Nouakchott.South AmericaDuffy Blood-Group System: A blood group consisting mainly of the antigens Fy(a) and Fy(b), determined by allelic genes, the frequency of which varies profoundly in different human groups; amorphic genes are common.Splenomegaly: Enlargement of the spleen.Atlantic Islands: Widely scattered islands in the Atlantic Ocean as far north as the AZORES and as far south as the South Sandwich Islands, with the greatest concentration found in the CARIBBEAN REGION. They include Annobon Island, Ascension, Canary Islands, Falkland Islands, Fernando Po (also called Isla de Bioko and Bioko), Gough Island, Madeira, Sao Tome and Principe, Saint Helena, and Tristan da Cunha.Azure Stains: PHENOTHIAZINES with an amino group at the 3-position that are green crystals or powder. They are used as biological stains.Haplotypes: The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.Hemoglobin C: A commonly occurring abnormal hemoglobin in which lysine replaces a glutamic acid residue at the sixth position of the beta chains. It results in reduced plasticity of erythrocytes.Comoros: A group of Indian Ocean Islands, the islands of Great Comoro, Anjouan, Mayotte, and Moheli, lying between northeast Mozambique and northwest Madagascar. The capital is Moroni. In 1914 they became a colony attached to Madagascar administratively and were made a French overseas territory in 1947. Except for Mayotte which remained French, Comoros became an independent republic in 1975. Comoros represents the Arabic qamar, moon, said by some scholars to be linked with the mystical Mountains of the Moon said to be somewhere in equatorial Africa. (From Webster's New Geographical Dictionary, 1988, p283 & Room, Brewer's Dictionary of Names, 1992, p122)L-Lactate Dehydrogenase: A tetrameric enzyme that, along with the coenzyme NAD+, catalyzes the interconversion of LACTATE and PYRUVATE. In vertebrates, genes for three different subunits (LDH-A, LDH-B and LDH-C) exist.Saimiri: A genus of the family CEBIDAE consisting of four species: S. boliviensis, S. orstedii (red-backed squirrel monkey), S. sciureus (common squirrel monkey), and S. ustus. They inhabit tropical rain forests in Central and South America. S. sciureus is used extensively in research studies.Sequence Alignment: The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.Plasmodium gallinaceum: A protozoan parasite that causes avian malaria (MALARIA, AVIAN), primarily in chickens, and is transmitted by the Aedes mosquito.Merozoites: Uninuclear cells or a stage in the life cycle of sporozoan protozoa. Merozoites, released from ruptured multinucleate SCHIZONTS, enter the blood stream and infect the ERYTHROCYTES.Afghanistan