Chikungunya virus: A species of ALPHAVIRUS causing an acute dengue-like fever.Alphavirus Infections: Virus diseases caused by members of the ALPHAVIRUS genus of the family TOGAVIRIDAE.Reunion: One of the Indian Ocean Islands, east of Madagascar. Its capital is Saint-Denis. It was discovered in 1507 by the Portuguese and claimed by France in 1638. It was first colonized in 1662 as Isle de Bourbon but renamed Reunion in 1793. In 1946 it was made an overseas department of France. The name commemorates the reunion of the revolutionaries from Marseilles with the National Guard in Paris in 1792. (From Webster's New Geographical Dictionary, 1988, p1011; Room, Brewer's Dictionary of Names, 1992, p454; French Embassy)Aedes: A genus of mosquitoes (CULICIDAE) frequently found in tropical and subtropical regions. YELLOW FEVER and DENGUE are two of the diseases that can be transmitted by species of this genus.Indian Ocean Islands: Numerous islands in the Indian Ocean situated east of Madagascar, north to the Arabian Sea and east to Sri Lanka. Included are COMOROS (republic), MADAGASCAR (republic), Maldives (republic), MAURITIUS (parliamentary democracy), Pemba (administered by Tanzania), REUNION (a department of France), and SEYCHELLES (republic).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)Disease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Insect Vectors: Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Alphavirus: A genus of TOGAVIRIDAE, also known as Group A arboviruses, serologically related to each other but not to other Togaviridae. The viruses are transmitted by mosquitoes. The type species is the SINDBIS VIRUS.Arbovirus Infections: Infections caused by arthropod-borne viruses, general or unspecified.Indian Ocean: A body of water covering approximately one-fifth of the total ocean area of the earth, extending amidst Africa in the west, Australia in the east, Asia in the north, and Antarctica in the south. Including the Red Sea and the Persian Gulf, it constitutes the third largest ocean after the ATLANTIC OCEAN and the PACIFIC OCEAN. (New Encyclopaedia Britannica Micropaedia, 15th ed, 1990, p289)Ross River virus: A species of ALPHAVIRUS associated with epidemic EXANTHEMA and polyarthritis in Australia.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.Africa, Central: The geographical area of Africa comprising CAMEROON; CENTRAL AFRICAN REPUBLIC; CHAD; CONGO; EQUATORIAL GUINEA; GABON; and DEMOCRATIC REPUBLIC OF THE CONGO.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Communicable Diseases, Emerging: Infectious diseases that are novel in their outbreak ranges (geographic and host) or transmission mode.Africa, Eastern: The geographical area of Africa comprising BURUNDI; DJIBOUTI; ETHIOPIA; KENYA; RWANDA; SOMALIA; SUDAN; TANZANIA; and UGANDA.Arboviruses: Arthropod-borne viruses. A non-taxonomic designation for viruses that can replicate in both vertebrate hosts and arthropod vectors. Included are some members of the following families: ARENAVIRIDAE; BUNYAVIRIDAE; REOVIRIDAE; TOGAVIRIDAE; and FLAVIVIRIDAE. (From Dictionary of Microbiology and Molecular Biology, 2nd ed)Virus Replication: The process of intracellular viral multiplication, consisting of the synthesis of PROTEINS; NUCLEIC ACIDS; and sometimes LIPIDS, and their assembly into a new infectious particle.Travel: Aspects of health and disease related to travel.Arthralgia: Pain in the joint.Dengue: An acute febrile disease transmitted by the bite of AEDES mosquitoes infected with DENGUE VIRUS. It is self-limiting and characterized by fever, myalgia, headache, and rash. SEVERE DENGUE is a more virulent form of dengue.Sindbis Virus: The type species of ALPHAVIRUS normally transmitted to birds by CULEX mosquitoes in Egypt, South Africa, India, Malaya, the Philippines, and Australia. It may be associated with fever in humans. Serotypes (differing by less than 17% in nucleotide sequence) include Babanki, Kyzylagach, and Ockelbo viruses.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Vero Cells: A CELL LINE derived from the kidney of the African green (vervet) monkey, (CERCOPITHECUS AETHIOPS) used primarily in virus replication studies and plaque assays.IndiaPhylogeny: The relationships of groups of organisms as reflected by their genetic makeup.RNA Viruses: Viruses whose genetic material is RNA.Malaysia: A parliamentary democracy with a constitutional monarch in southeast Asia, consisting of 11 states (West Malaysia) on the Malay Peninsula and two states (East Malaysia) on the island of BORNEO. It is also called the Federation of Malaysia. Its capital is Kuala Lumpur. Before 1963 it was the Union of Malaya. It reorganized in 1948 as the Federation of Malaya, becoming independent from British Malaya in 1957 and becoming Malaysia in 1963 as a federation of Malaya, Sabah, Sarawak, and Singapore (which seceded in 1965). The form Malay- probably derives from the Tamil malay, mountain, with reference to its geography. (From Webster's New Geographical Dictionary, 1988, p715 & Room, Brewer's Dictionary of Names, 1992, p329)Viral Vaccines: Suspensions of attenuated or killed viruses administered for the prevention or treatment of infectious viral disease.Dengue Virus: A species of the genus FLAVIVIRUS which causes an acute febrile and sometimes hemorrhagic disease in man. Dengue is mosquito-borne and four serotypes are known.Angola: A republic in southern Africa, southwest of DEMOCRATIC REPUBLIC OF THE CONGO and west of ZAMBIA. Its capital is Luanda.Antibodies, Neutralizing: Antibodies that reduce or abolish some biological activity of a soluble antigen or infectious agent, usually a virus.Cercopithecus aethiops: A species of CERCOPITHECUS containing three subspecies: C. tantalus, C. pygerythrus, and C. sabeus. They are found in the forests and savannah of Africa. The African green monkey (C. pygerythrus) is the natural host of SIMIAN IMMUNODEFICIENCY VIRUS and is used in AIDS research.Vaccinia virus: The type species of ORTHOPOXVIRUS, related to COWPOX VIRUS, but whose true origin is unknown. It has been used as a live vaccine against SMALLPOX. It is also used as a vector for inserting foreign DNA into animals. Rabbitpox virus is a subspecies of VACCINIA VIRUS.Gabon: A republic in west equatorial Africa, south of CAMEROON and west of the CONGO. Its capital is Libreville.Disease Vectors: Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.Host Specificity: The properties of a pathogen that makes it capable of infecting one or more specific hosts. The pathogen can include PARASITES as well as VIRUSES; BACTERIA; FUNGI; or PLANTS.Virus Cultivation: Process of growing viruses in live animals, plants, or cultured cells.Viremia: The presence of viruses in the blood.Immunoglobulin M: A class of immunoglobulin bearing mu chains (IMMUNOGLOBULIN MU-CHAINS). IgM can fix COMPLEMENT. The name comes from its high molecular weight and originally being called a macroglobulin.