Hemorrhagic Fevers, Viral: A group of viral diseases of diverse etiology but having many similar clinical characteristics; increased capillary permeability, leukopenia, and thrombocytopenia are common to all. Hemorrhagic fevers are characterized by sudden onset, fever, headache, generalized myalgia, backache, conjunctivitis, and severe prostration, followed by various hemorrhagic symptoms. Hemorrhagic fever with kidney involvement is HEMORRHAGIC FEVER WITH RENAL SYNDROME.Hemorrhagic Fever, Crimean: A severe, often fatal disease in humans caused by the Crimean-Congo hemorrhagic fever virus (HEMORRHAGIC FEVER VIRUS, CRIMEAN-CONGO).Hemorrhagic Fever with Renal Syndrome: An acute febrile disease occurring predominately in Asia. It is characterized by fever, prostration, vomiting, hemorrhagic phenonema, shock, and renal failure. It is caused by any one of several closely related species of the genus Hantavirus. The most severe form is caused by HANTAAN VIRUS whose natural host is the rodent Apodemus agrarius. Milder forms are caused by SEOUL VIRUS and transmitted by the rodents Rattus rattus and R. norvegicus, and the PUUMALA VIRUS with transmission by Clethrionomys galreolus.Hemorrhagic Fever Virus, Crimean-Congo: A species of NAIROVIRUS of the family BUNYAVIRIDAE. It is primarily transmitted by ticks and causes a severe, often fatal disease in humans.Hemorrhagic Fever, American: Diseases caused by American hemorrhagic fever viruses (ARENAVIRUSES, NEW WORLD).Hemorrhagic Fever, Ebola: A highly fatal, acute hemorrhagic fever, clinically very similar to MARBURG VIRUS DISEASE, caused by EBOLAVIRUS, first occurring in the Sudan and adjacent northwestern (what was then) Zaire.Severe Dengue: A virulent form of dengue characterized by THROMBOCYTOPENIA and an increase in vascular permeability (grades I and II) and distinguished by a positive pain test (e.g., TOURNIQUET PAIN TEST). When accompanied by SHOCK (grades III and IV), it is called dengue shock syndrome.Fever: An abnormal elevation of body temperature, usually as a result of a pathologic process.Marburg Virus Disease: An RNA virus infection of rhesus, vervet, and squirrel monkeys transmissible to man.Hantaan virus: The type species of the genus HANTAVIRUS infecting the rodent Apodemus agrarius and humans who come in contact with it. It causes syndromes of hemorrhagic fever associated with vascular and especially renal pathology.Hantavirus: A genus of the family BUNYAVIRIDAE causing HANTAVIRUS INFECTIONS, first identified during the Korean war. Infection is found primarily in rodents and humans. Transmission does not appear to involve arthropods. HANTAAN VIRUS is the type species.Arenaviruses, New World: One of two groups of viruses in the ARENAVIRUS genus and considered part of the New World complex. It includes JUNIN VIRUS; PICHINDE VIRUS; Amapari virus, and Machupo virus among others. They are the cause of human hemorrhagic fevers mostly in Central and South America.Ebolavirus: A genus in the family FILOVIRIDAE consisting of several distinct species of Ebolavirus, each containing separate strains. These viruses cause outbreaks of a contagious, hemorrhagic disease (HEMORRHAGIC FEVER, EBOLA) in humans, usually with high mortality.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.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.Marburgvirus: A genus in the family FILOVIRIDAE consisting of one species (Lake Victoria marburgvirus) with several strains. The genus shows no antigenic cross-reactivity with EBOLAVIRUS.Junin virus: A species of ARENAVIRUS, part of the New World Arenaviruses (ARENAVIRUSES, NEW WORLD), causing Argentinian hemorrhagic fever. The disease is characterized by congestion, edema, generalized lymphadenopathy and hemorrhagic necrosis and is sometimes fatal.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.Q Fever: An acute infectious disease caused by COXIELLA BURNETII. It is characterized by a sudden onset of FEVER; HEADACHE; malaise; and weakness. In humans, it is commonly contracted by inhalation of infected dusts derived from infected domestic animals (ANIMALS, DOMESTIC).Lassa Fever: An acute febrile human disease caused by the LASSA VIRUS.Filoviridae Infections: Infections with viruses of the family FILOVIRIDAE. The infections in humans consist of a variety of clinically similar viral hemorrhagic fevers but the natural reservoir host is unknown.Arenaviridae Infections: Virus diseases caused by the ARENAVIRIDAE.Yellow Fever: An acute infectious disease primarily of the tropics, caused by a virus and transmitted to man by mosquitoes of the genera Aedes and Haemagogus. The severe form is characterized by fever, HEMOLYTIC JAUNDICE, and renal damage.Arenavirus: The only genus in the family ARENAVIRIDAE. It contains two groups ARENAVIRUSES, OLD WORLD and ARENAVIRUSES, NEW WORLD, which are distinguished by antigenic relationships and geographic distribution.Lassa virus: A species of ARENAVIRUS, part of the Old World Arenaviruses (ARENAVIRUSES, OLD WORLD), and the etiologic agent of LASSA FEVER. LASSA VIRUS is a common infective agent in humans in West Africa. Its natural host is the multimammate mouse Mastomys natalensis.Filoviridae: A family of RNA viruses, of the order MONONEGAVIRALES, containing filamentous virions. Although they resemble RHABDOVIRIDAE in possessing helical nucleocapsids, Filoviridae differ in the length and degree of branching in their virions. There are two genera: EBOLAVIRUS and MARBURGVIRUS.Puumala virus: A species of HANTAVIRUS causing nephropathia epidemica, a mild form of HEMORRHAGIC FEVER WITH RENAL SYNDROME. It is found in most of Europe and especially in Finland, along with its carrier rodent, the bank vole (Clethrionomys glareolus).Hemorrhagic Fever, Omsk: Infection with the Omsk hemorrhagic fever virus, a Flavivirus.Pichinde virus: A species of ARENAVIRUS, one of the New World Arenaviruses (ARENAVIRUSES, NEW WORLD), causing a fatal infection in the cricetine rodent Oryzomys albigularis. Asymptomatic laboratory infection in humans has been reported.Disease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Typhoid Fever: An acute systemic febrile infection caused by SALMONELLA TYPHI, a serotype of SALMONELLA ENTERICA.Arenaviridae: A family of RNA viruses naturally infecting rodents and consisting of one genus (ARENAVIRUS) with two groups: Old World Arenaviruses (ARENAVIRUSES, OLD WORLD) and New World Arenaviruses (ARENAVIRUSES, NEW WORLD). Infection in rodents is persistent and silent. Vertical transmission is through milk-, saliva-, or urine-borne routes. Horizontal transmission to humans, monkeys, and other animals is important.Rift Valley Fever: An acute infection caused by the RIFT VALLEY FEVER VIRUS, an RNA arthropod-borne virus, affecting domestic animals and humans. In animals, symptoms include HEPATITIS; abortion (ABORTION, VETERINARY); and DEATH. In humans, symptoms range from those of a flu-like disease to hemorrhagic fever, ENCEPHALITIS, or BLINDNESS.Hantavirus Infections: Infections with viruses of the genus HANTAVIRUS. This is associated with at least four clinical syndromes: HEMORRHAGIC FEVER WITH RENAL SYNDROME caused by viruses of the Hantaan group; a milder form of HFRS caused by SEOUL VIRUS; nephropathia epidemica caused by PUUMALA VIRUS; and HANTAVIRUS PULMONARY SYNDROME caused by SIN NOMBRE VIRUS.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Arterivirus: A genus of the family ARTERIVIRIDAE, in the order NIDOVIRALES. The type species is ARTERITIS VIRUS, EQUINE.Fever of Unknown Origin: Fever in which the etiology cannot be ascertained.Nairovirus: A genus of the family BUNYAVIRIDAE named after NAIROBI SHEEP DISEASE, an acute, hemorrhagic, tick-borne, gastroenteritis affecting sheep and goats. The type species is Dugbe virus. Some viruses in this genus are capable of causing severe and fatal disease in humans.Seoul virus: A species of HANTAVIRUS causing a less severe form of HEMORRHAGIC FEVER WITH RENAL SYNDROME in Asia (primarily Korea and Japan). It is transmitted by rats, especially Rattus rattus and R. norvegicus.Ticks: Blood-sucking acarid parasites of the order Ixodida comprising two families: the softbacked ticks (ARGASIDAE) and hardbacked ticks (IXODIDAE). Ticks are larger than their relatives, the MITES. They penetrate the skin of their host by means of highly specialized, hooked mouth parts and feed on its blood. Ticks attack all groups of terrestrial vertebrates. In humans they are responsible for many TICK-BORNE DISEASES, including the transmission of ROCKY MOUNTAIN SPOTTED FEVER; TULAREMIA; BABESIOSIS; AFRICAN SWINE FEVER; and RELAPSING FEVER. (From Barnes, Invertebrate Zoology, 5th ed, pp543-44)Murinae: A subfamily in the family MURIDAE, comprising the Old World MICE and RATS.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.Bunyaviridae: A family of viruses, mainly arboviruses, consisting of a single strand of RNA. Virions are enveloped particles 90-120 nm diameter. The complete family contains over 300 members arranged in five genera: ORTHOBUNYAVIRUS; HANTAVIRUS; NAIROVIRUS; PHLEBOVIRUS; and TOSPOVIRUS.Rheumatic Fever: A febrile disease occurring as a delayed sequela of infections with STREPTOCOCCUS PYOGENES. It is characterized by multiple focal inflammatory lesions of the connective tissue structures, such as the heart, blood vessels, and joints (POLYARTHRITIS) and brain, and by the presence of ASCHOFF BODIES in the myocardium and skin.Communicable Diseases, Emerging: Infectious diseases that are novel in their outbreak ranges (geographic and host) or transmission mode.Hantavirus Pulmonary Syndrome: Acute respiratory illness in humans caused by the Muerto Canyon virus whose primary rodent reservoir is the deer mouse Peromyscus maniculatus. First identified in the southwestern United States, this syndrome is characterized most commonly by fever, myalgias, headache, cough, and rapid respiratory failure.Disease Reservoirs: Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (DISEASE VECTORS) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks.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.Bunyaviridae Infections: Virus diseases caused by the BUNYAVIRIDAE.Yugoslavia: Created as the Kingdom of Serbs, Croats, and Slovenes in 1918. Yugoslavia became the official name in 1929. BOSNIA-HERZEGOVINA; CROATIA; and SLOVENIA formed independent countries 7 April 1992. Macedonia became independent 8 February 1994 as the Former Yugoslav Republic of Macedonia (MACEDONIA REPUBLIC).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.Ebola Vaccines: Vaccines or candidate vaccines used to prevent EBOLA HEMORRHAGIC FEVER.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.TurkeyRodentia: A mammalian order which consists of 29 families and many genera.Ixodidae: A family of hardbacked TICKS, in the subclass ACARI. Genera include DERMACENTOR and IXODES among others.Angola: A republic in southern Africa, southwest of DEMOCRATIC REPUBLIC OF THE CONGO and west of ZAMBIA. Its capital is Luanda.Rift Valley fever virus: A mosquito-borne species of the PHLEBOVIRUS genus found in eastern, central, and southern Africa, producing massive hepatitis, abortion, and death in sheep, goats, cattle, and other animals. It also has caused disease in humans.Arachnid Vectors: Members of the class Arachnida, especially SPIDERS; SCORPIONS; MITES; and TICKS; which transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Viral Vaccines: Suspensions of attenuated or killed viruses administered for the prevention or treatment of infectious viral disease.Livestock: Domesticated farm animals raised for home use or profit but excluding POULTRY. Typically livestock includes CATTLE; SHEEP; HORSES; SWINE; GOATS; and others.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)Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Antibody-Dependent Enhancement: Enhancement of viral infectivity caused by non-neutralizing antibodies. There are at least two mechanisms known to account for this: mediation by Fc receptors (RECEPTORS, FC) or by complement receptors (RECEPTORS, COMPLEMENT). Either the virus is complexed with antiviral IMMUNOGLOBULIN G and binds to Fc receptors, or virus is coated with antiviral IMMUNOGLOBULIN M and binds to complement receptors.Thailand: Formerly known as Siam, this is a Southeast Asian nation at the center of the Indochina peninsula. Bangkok is the capital city.Patient Isolation: The segregation of patients with communicable or other diseases for a specified time. Isolation may be strict, in which movement and social contacts are limited; modified, where an effort to control specified aspects of care is made in order to prevent cross infection; or reverse, where the patient is secluded in a controlled or germ-free environment in order to protect him or her from cross infection.Travel: Aspects of health and disease related to travel.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)Arenaviruses, Old World: One of two groups of viruses in the ARENAVIRUS genus and considered part of the Old World complex. It includes LASSA VIRUS and LYMPHOCYTIC CHORIOMENINGITIS VIRUS, although the latter has worldwide distribution now.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.Seroepidemiologic Studies: EPIDEMIOLOGIC STUDIES based on the detection through serological testing of characteristic change in the serum level of specific ANTIBODIES. Latent subclinical infections and carrier states can thus be detected in addition to clinically overt cases.Encephalitis Viruses, Tick-Borne: A subgroup of the genus FLAVIVIRUS that causes encephalitis and hemorrhagic fevers and is found in eastern and western Europe and the former Soviet Union. It is transmitted by TICKS and there is an associated milk-borne transmission from viremic cattle, goats, and sheep.Disease Vectors: Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.Virus Internalization: The entering of cells by viruses following VIRUS ATTACHMENT. This is achieved by ENDOCYTOSIS, by direct MEMBRANE FUSION of the viral membrane with the CELL MEMBRANE, or by translocation of the whole virus across the cell membrane.Tick-Borne Diseases: Bacterial, viral, or parasitic diseases transmitted to humans and animals by the bite of infected ticks. The families Ixodidae and Argasidae contain many bloodsucking species that are important pests of man and domestic birds and mammals and probably exceed all other arthropods in the number and variety of disease agents they transmit. Many of the tick-borne diseases are zoonotic.Boutonneuse Fever: A febrile disease of the Mediterranean area, the Crimea, Africa, and India, caused by infection with RICKETTSIA CONORII.Zoonoses: Diseases of non-human animals that may be transmitted to HUMANS or may be transmitted from humans to non-human animals.African Swine Fever Virus: The lone species of the genus Asfivirus. It infects domestic and wild pigs, warthogs, and bushpigs. Disease is endemic in domestic swine in many African countries and Sardinia. Soft ticks of the genus Ornithodoros are also infected and act as vectors.Viremia: The presence of viruses in the blood.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.Sin Nombre virus: A species of HANTAVIRUS which emerged in the Four Corners area of the United States in 1993. It causes a serious, often fatal pulmonary illness (HANTAVIRUS PULMONARY SYNDROME) in humans. Transmission is by inhaling aerosolized rodent secretions that contain virus particles, carried especially by deer mice (PEROMYSCUS maniculatus) and pinyon mice (P. truei).Antigens, Viral: Substances elaborated by viruses that have antigenic activity.Togaviridae: A family of RNA viruses, mainly arboviruses, consisting of two genera: ALPHAVIRUS (group A arboviruses), and RUBIVIRUS. Virions are spherical, 60-70 nm in diameter, with a lipoprotein envelope tightly applied to the icosahedral nucleocapsid.Rocky Mountain Spotted Fever: An acute febrile illness caused by RICKETTSIA RICKETTSII. It is transmitted to humans by bites of infected ticks and occurs only in North and South America. Characteristics include a sudden onset with headache and chills and fever lasting about two to three weeks. A cutaneous rash commonly appears on the extremities and trunk about the fourth day of illness.Ribavirin: A nucleoside antimetabolite antiviral agent that blocks nucleic acid synthesis and is used against both RNA and DNA viruses.Antiviral Agents: Agents used in the prophylaxis or therapy of VIRUS DISEASES. Some of the ways they may act include preventing viral replication by inhibiting viral DNA polymerase; binding to specific cell-surface receptors and inhibiting viral penetration or uncoating; inhibiting viral protein synthesis; or blocking late stages of virus assembly.Nucleocapsid Proteins: Viral proteins found in either the NUCLEOCAPSID or the viral core (VIRAL CORE PROTEINS).Arvicolinae: A subfamily of MURIDAE found nearly world-wide and consisting of about 20 genera. Voles, lemmings, and muskrats are members.Paratyphoid Fever: A prolonged febrile illness commonly caused by several Paratyphi serotypes of SALMONELLA ENTERICA. It is similar to TYPHOID FEVER but less severe.China: A country spanning from central Asia to the Pacific Ocean.Classical Swine Fever: An acute, highly contagious disease affecting swine of all ages and caused by the CLASSICAL SWINE FEVER VIRUS. It has a sudden onset with high morbidity and mortality.Animal Structures: Organs and other anatomical structures of non-human vertebrate and invertebrate animals.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)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.Orthobunyavirus: A genus of the family BUNYAVIRIDAE containing over 150 viruses, most of which are transmitted by mosquitoes or flies. They are arranged in groups defined by serological criteria, each now named for the original reference species (previously called serogroups). Many species have multiple serotypes or strains.Mauritania: A republic in western Africa, southwest of ALGERIA and west of MALI. Its capital is Nouakchott.Sudan: A country in northeastern Africa. The capital is Khartoum.Rodent Diseases: Diseases of rodents of the order RODENTIA. This term includes diseases of Sciuridae (squirrels), Geomyidae (gophers), Heteromyidae (pouched mice), Castoridae (beavers), Cricetidae (rats and mice), Muridae (Old World rats and mice), Erethizontidae (porcupines), and Caviidae (guinea pigs).Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Flavivirus: A genus of FLAVIVIRIDAE containing several subgroups and many species. Most are arboviruses transmitted by mosquitoes or ticks. The type species is YELLOW FEVER VIRUS.Muridae: A family of the order Rodentia containing 250 genera including the two genera Mus (MICE) and Rattus (RATS), from which the laboratory inbred strains are developed. The fifteen subfamilies are SIGMODONTINAE (New World mice and rats), CRICETINAE, Spalacinae, Myospalacinae, Lophiomyinae, ARVICOLINAE, Platacanthomyinae, Nesomyinae, Otomyinae, Rhizomyinae, GERBILLINAE, Dendromurinae, Cricetomyinae, MURINAE (Old World mice and rats), and Hydromyinae.Encephalitis, Tick-Borne: Encephalitis caused by neurotropic viruses that are transmitted via the bite of TICKS. In Europe, the diseases are caused by ENCEPHALITIS VIRUSES, TICK-BORNE, which give rise to Russian spring-summer encephalitis, central European encephalitis, louping ill encephalitis, and related disorders. Powassan encephalitis occurs in North America and Russia and is caused by the Powassan virus. ASEPTIC MENINGITIS and rarely encephalitis may complicate COLORADO TICK FEVER which is endemic to mountainous regions of the western United States. (From Joynt, Clinical Neurology, 1996, Ch26, pp14-5)Phlebovirus: A genus of the family BUNYAVIRIDAE comprising many viruses, most of which are transmitted by Phlebotomus flies and cause PHLEBOTOMUS FEVER. The type species is RIFT VALLEY FEVER VIRUS.VenezuelaUganda: A republic in eastern Africa, south of SUDAN and west of KENYA. Its capital is Kampala.Contact Tracing: Identification of those persons (or animals) who have had such an association with an infected person, animal, or contaminated environment as to have had the opportunity to acquire the infection. Contact tracing is a generally accepted method for the control of sexually transmitted diseases.Cuba: An island in the Greater Antilles in the West Indies, south of Florida. With the adjacent islands it forms the Republic of Cuba. Its capital is Havana. It was discovered by Columbus on his first voyage in 1492 and conquered by Spain in 1511. It has a varied history under Spain, Great Britain, and the United States but has been independent since 1902. The name Cuba is said to be an Indian name of unknown origin but the language that gave the name is extinct, so the etymology is a conjecture. (From Webster's New Geographical Dictionary, 1988, p302 & Room, Brewer's Dictionary of Names, 1992, p132)Serotyping: Process of determining and distinguishing species of bacteria or viruses based on antigens they share.BoliviaInsect Vectors: Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Ornithodoros: A genus of softbacked TICKS, in the family ARGASIDAE, serving as the vector of BORRELIA, causing RELAPSING FEVER, and of the AFRICAN SWINE FEVER VIRUS.African Swine Fever: A sometimes fatal ASFIVIRUS infection of pigs, characterized by fever, cough, diarrhea, hemorrhagic lymph nodes, and edema of the gallbladder. It is transmitted between domestic swine by direct contact, ingestion of infected meat, or fomites, or mechanically by biting flies or soft ticks (genus Ornithodoros).Immunoglobulin G: The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of IgG, for example, IgG1, IgG2A, and IgG2B.Viral Envelope Proteins: Layers of protein which surround the capsid in animal viruses with tubular nucleocapsids. The envelope consists of an inner layer of lipids and virus specified proteins also called membrane or matrix proteins. The outer layer consists of one or more types of morphological subunits called peplomers which project from the viral envelope; this layer always consists of glycoproteins.Nucleoproteins: Proteins conjugated with nucleic acids.Adolescent, Hospitalized: Adolescent hospitalized for short term care.Coxiella burnetii: A species of gram-negative bacteria that grows preferentially in the vacuoles of the host cell. It is the etiological agent of Q FEVER.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Arterivirus Infections: Infections caused by viruses of the genus ARTERIVIRUS.RNA Viruses: Viruses whose genetic material is RNA.Funeral Rites: Those customs and ceremonies pertaining to the dead.Sierra Leone: A republic in western Africa, south of GUINEA and west of LIBERIA. Its capital is Freetown.Geography, Medical: The area of medicine concerned with the effects on health and disease due to geographic factors such as CLIMATE, environmental conditions, and geographic location.Kyasanur Forest Disease: Tick-borne flavivirus infection occurring in the Kyasanur Forest in India.Slovenia: Created 7 April 1992 as a result of the division of Yugoslavia.VietnamVirus 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.Montenegro: Montenegro was formerly part of the historic Kingdom of Yugoslavia. Following World War II, Montenegro was granted the status of a republic within YUGOSLAVIA. On May 21, 2006, the Republic of Montenegro held a successful referendum on independence and declared independence on June 3. The capital is Podgorica.Imino Sugars: Sugars in which the OXYGEN is replaced by a NITROGEN atom. This substitution prevents normal METABOLISM resulting in inhibition of GLYCOSIDASES and GLYCOSYLTRANSFERASES.Burial: The act or ceremony of putting a corpse into the ground or a vault, or into the sea; or the inurnment of CREMAINS.Reverse Transcriptase Polymerase Chain Reaction: A variation of the PCR technique in which cDNA is made from RNA via reverse transcription. The resultant cDNA is then amplified using standard PCR protocols.Thrombocytopenia: A subnormal level of BLOOD PLATELETS.Arbovirus Infections: Infections caused by arthropod-borne viruses, general or unspecified.Infectious Disease Incubation Period: The amount time between exposure to an infectious agent and becoming symptomatic.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Congo: A republic in central Africa lying between GABON and DEMOCRATIC REPUBLIC OF THE CONGO and south of Cameroon. Its capital is Brazzaville.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.Sri LankaViral Proteins: Proteins found in any species of virus.Transferrins: A group of iron-binding proteins that tightly bind two ferrate ions along with two carbonate ions. They are found in the bodily fluids of vertebrates where they act as transport and storage molecules for iron.ArgentinaAntibodies, Neutralizing: Antibodies that reduce or abolish some biological activity of a soluble antigen or infectious agent, usually a virus.Rhabdoviridae: A family of bullet-shaped viruses of the order MONONEGAVIRALES, infecting vertebrates, arthropods, protozoa, and plants. Genera include VESICULOVIRUS; LYSSAVIRUS; EPHEMEROVIRUS; NOVIRHABDOVIRUS; Cytorhabdovirus; and Nucleorhabdovirus.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.BulgariaMyanmar: 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)Cell Line: Established cell cultures that have the potential to propagate indefinitely.IranPolygeline: A 3.5 per cent colloidal solution containing urea-cross-linked polymerized peptides. It has a molecular weight of approximately 35,000 and is prepared from gelatin and electrolytes. The polymeric solution is used as a plasma expander.AfricaDisease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.PakistanEpidemiologic Factors: Events, characteristics, or other definable entities that have the potential to bring about a change in a health condition or other defined outcome.Flavivirus Infections: Infections with viruses of the genus FLAVIVIRUS, family FLAVIVIRIDAE.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.Dengue Vaccines: Vaccines or candidate vaccines used to prevent infection with DENGUE VIRUS. These include live-attenuated, subunit, DNA, and inactivated vaccines.Neutralization Tests: The measurement of infection-blocking titer of ANTISERA by testing a series of dilutions for a given virus-antiserum interaction end-point, which is generally the dilution at which tissue cultures inoculated with the serum-virus mixtures demonstrate cytopathology (CPE) or the dilution at which 50% of test animals injected with serum-virus mixtures show infectivity (ID50) or die (LD50).Laboratory Proficiency Testing: Assessments aimed at determining agreement in diagnostic test results among laboratories. Identical survey samples are distributed to participating laboratories, with results stratified according to testing methodologies.Serologic Tests: Diagnostic procedures involving immunoglobulin reactions.Viral Nonstructural Proteins: Proteins encoded by a VIRAL GENOME that are produced in the organisms they infect, but not packaged into the VIRUS PARTICLES. Some of these proteins may play roles within the infected cell during VIRUS REPLICATION or act in regulation of virus replication or VIRUS ASSEMBLY.Polynesia: The collective name for the islands of the central Pacific Ocean, including the Austral Islands, Cook Islands, Easter Island, HAWAII; NEW ZEALAND; Phoenix Islands, PITCAIRN ISLAND; SAMOA; TONGA; Tuamotu Archipelago, Wake Island, and Wallis and Futuna Islands. Polynesians are of the Caucasoid race, but many are of mixed origin. Polynesia is from the Greek poly, many + nesos, island, with reference to the many islands in the group. (From Webster's New Geographical Dictionary, 1988, p966 & Room, Brewer's Dictionary of Names, 1992, p426)Tick Infestations: Infestations with soft-bodied (Argasidae) or hard-bodied (Ixodidae) ticks.Climate: The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Viral Plaque Assay: Method for measuring viral infectivity and multiplication in CULTURED CELLS. Clear lysed areas or plaques develop as the VIRAL PARTICLES are released from the infected cells during incubation. With some VIRUSES, the cells are killed by a cytopathic effect; with others, the infected cells are not killed but can be detected by their hemadsorptive ability. Sometimes the plaque cells contain VIRAL ANTIGENS which can be measured by IMMUNOFLUORESCENCE.Salmonella typhi: A serotype of SALMONELLA ENTERICA which is the etiologic agent of TYPHOID FEVER.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)Oliguria: Decreased URINE output that is below the normal range. Oliguria can be defined as urine output of less than or equal to 0.5 or 1 ml/kg/hr depending on the age.Rain: Water particles that fall from the ATMOSPHERE.Pituitary Apoplexy: The sudden loss of blood supply to the PITUITARY GLAND, leading to tissue NECROSIS and loss of function (PANHYPOPITUITARISM). The most common cause is hemorrhage or INFARCTION of a PITUITARY ADENOMA. It can also result from acute hemorrhage into SELLA TURCICA due to HEAD TRAUMA; INTRACRANIAL HYPERTENSION; or other acute effects of central nervous system hemorrhage. Clinical signs include severe HEADACHE; HYPOTENSION; bilateral visual disturbances; UNCONSCIOUSNESS; and COMA.Host-Pathogen Interactions: The interactions between a host and a pathogen, usually resulting in disease.Bites and StingsSequence Homology: The degree of similarity between sequences. Studies of AMINO ACID SEQUENCE HOMOLOGY and NUCLEIC ACID SEQUENCE HOMOLOGY provide useful information about the genetic relatedness of genes, gene products, and species.Virology: The study of the structure, growth, function, genetics, and reproduction of viruses, and VIRUS DISEASES.Sheep Diseases: Diseases of domestic and mountain sheep of the genus Ovis.Molecular Epidemiology: The application of molecular biology to the answering of epidemiological questions. The examination of patterns of changes in DNA to implicate particular carcinogens and the use of molecular markers to predict which individuals are at highest risk for a disease are common examples.Glycoproteins: Conjugated protein-carbohydrate compounds including mucins, mucoid, and amyloid glycoproteins.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Vaccines, Attenuated: Live vaccines prepared from microorganisms which have undergone physical adaptation (e.g., by radiation or temperature conditioning) or serial passage in laboratory animal hosts or infected tissue/cell cultures, in order to produce avirulent mutant strains capable of inducing protective immunity.Epidemics: Sudden outbreaks of a disease in a country or region not previously recognized in that area, or a rapid increase in the number of new cases of a previous existing endemic disease. Epidemics can also refer to outbreaks of disease in animal or plant populations.Asymptomatic Infections: Infections that do not exhibit symptoms.NicaraguaHemagglutination Inhibition Tests: Serologic tests in which a known quantity of antigen is added to the serum prior to the addition of a red cell suspension. Reaction result is expressed as the smallest amount of antigen which causes complete inhibition of hemagglutination.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Disseminated Intravascular Coagulation: A disorder characterized by procoagulant substances entering the general circulation causing a systemic thrombotic process. The activation of the clotting mechanism may arise from any of a number of disorders. A majority of the patients manifest skin lesions, sometimes leading to PURPURA FULMINANS.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Chiroptera: Order of mammals whose members are adapted for flight. It includes bats, flying foxes, and fruit bats.Insect Bites and Stings: Bites and stings inflicted by insects.Animals, Domestic: Animals which have become adapted through breeding in captivity to a life intimately associated with humans. They include animals domesticated by humans to live and breed in a tame condition on farms or ranches for economic reasons, including LIVESTOCK (specifically CATTLE; SHEEP; HORSES; etc.), POULTRY; and those raised or kept for pleasure and companionship, e.g., PETS; or specifically DOGS; CATS; etc.Primate Diseases: Diseases of animals within the order PRIMATES. This term includes diseases of Haplorhini and Strepsirhini.Population Surveillance: Ongoing scrutiny of a population (general population, study population, target population, etc.), generally using methods distinguished by their practicability, uniformity, and frequently their rapidity, rather than by complete accuracy.Macaca fascicularis: A species of the genus MACACA which typically lives near the coast in tidal creeks and mangrove swamps primarily on the islands of the Malay peninsula.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)Rickettsia Infections: Infections by the genus RICKETTSIA.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Nucleocapsid: A protein-nucleic acid complex which forms part or all of a virion. It consists of a CAPSID plus enclosed nucleic acid. Depending on the virus, the nucleocapsid may correspond to a naked core or be surrounded by a membranous envelope.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Phlebotomus Fever: Influenza-like febrile viral disease caused by several members of the BUNYAVIRIDAE family and transmitted mostly by the bloodsucking sandfly Phlebotomus papatasii.Rickettsia: A genus of gram-negative, aerobic, rod-shaped bacteria often surrounded by a protein microcapsular layer and slime layer. The natural cycle of its organisms generally involves a vertebrate and an invertebrate host. Species of the genus are the etiological agents of human diseases, such as typhus.Shock: A pathological condition manifested by failure to perfuse or oxygenate vital organs.Infection Control: Programs of disease surveillance, generally within health care facilities, designed to investigate, prevent, and control the spread of infections and their causative microorganisms.Gabon: A republic in west equatorial Africa, south of CAMEROON and west of the CONGO. Its capital is Libreville.
Natural reservoir: A natural reservoir or nidus (the latter from the Latin word for "nest") is the long-term host of a pathogen of an infectious disease. Hosts often do not get the disease carried by the pathogen or it is carried as a subclinical infection and so asymptomatic and non-lethal.Nephropathia epidemicaCrimean–Congo hemorrhagic feverArgentine hemorrhagic feverBundibugyo virus: Bundibugyo virus (BDBV) is a close relative of the much more commonly known Ebola virus (EBOV). BDBV causes severe disease in humans and (experimentally) in nonhuman primates, the Ebola hemorrhagic fever.Rabbit feverMarburg virus: Marburg virus ( ) is a hemorrhagic fever virus of the Filoviridae family of viruses and a member of the species Marburg marburgvirus, genus Marburgvirus. Marburg virus (MARV) causes Marburg virus disease in humans and nonhuman primates, a form of viral hemorrhagic fever.Andes virusEbola virus: Ebolavirus|other uses|Ebola (disambiguation)Ebola}}Dengue fever outbreaksMarburg marburgvirus: The species Marburg marburgvirus is the taxonomic home of two related viruses that form filamentous virions, Marburg virus (MARV) and Ravn virus (RAVV). Both viruses cause Marburg virus disease in humans and nonhuman primates, a form of viral hemorrhagic fever, and both are Select Agents, World Health Organization Risk Group 4 Pathogens (requiring Biosafety Level 4-equivalent containment), National Institutes of Health/National Institute of Allergy and Infectious Diseases Category A Priority Pathogens, Centers for Disease Control and Prevention Category A Bioterrorism Agents, and are listed as a Biological Agents for Export Control by the Australia Group.Copper mining in the Democratic Republic of the Congo: Copper mining in the Democratic Republic of the Congo mainly takes place in the Copper Belt of the southern Katanga Province of the Democratic Republic of the Congo.The Tyrant (House)Haemagogus: Haemagogus, is a genus of mosquitoes belonging to the family Culicidae. They mainly occur in Central America and northern South America (including Trinidad), although some species inhabit forested areas of Brazil, and range as far as northern Argentina.Arenavirus: An arenavirus is a virus which is a member of the family Arenaviridae. These viruses infect rodents and occasionally humans; arenaviruses have also been discovered which infect snakes.Josiah WarrenCuevavirus: Cuevavirus is a genus in the family Filoviridae that has one species, Lloviu cuevavirus (LLOV). LLOV is a distant relative of the more widely known Ebola and Marburg viruses.Puumala virus: Puumala virus (PUUV) is a species of hantavirus. Humans infected with the virus may develop a haemorrhagic fever with renal syndrome (HFRS) known as nephropathia epidemica.Omsk Medical Academy: The Omsk State Medical Academy (OSMA) is a school of medicine in Omsk, Russia. It was founded as the Medical Faculty of the Siberian Institute of Veterinary Medicine and Zoology in 1920, and reorganized as the West Siberian State Medical Institute in 1921.Interferon alfacon-1National Outbreak Reporting System: ==The National Outbreak Reporting System (NORS)==Widal test: The Widal test, developed in 1896 and named after Georges-Fernand Widal, who introduced it, is a presumptive serological test for enteric fever or undulant fever whereby bacteria causing typhoid fever are mixed with a serum containing specific antibodies obtained from an infected individual. In cases of Salmonella infection, it is a demonstration of the presence of O-soma false-positive result.Musbury Valley: The Musbury Valley is a small valley in the east Pennines, west of Helmshore and Haslingden in Rossendale, Lancashire. The valley is very picturesque and includes a variety of landscapes, mostly sheep pasture and moors but there are some patches of beautiful woodland here and there.Arterivirus: Arterivirus is the only genus of viruses in the family Arteriviridae, which is within the order Nidovirales. Vertebrates serve as natural hosts.Eggs and Marrowbone: "Eggs and Marrowbone" (Laws Q2, Roud183]) is a traditional folk song of unknown origins and multiple variations. The most well known variations are "The Old Woman From Boston" and "The Rich Old Lady".Seoul virus: Seoul virus (SEOV) is a species of hantavirus that can cause a form of hemorrhagic fever.Ticks of domestic animals: Ticks of domestic animals directly cause poor health and loss of production to their hosts by many parasitic mechanisms. Ticks also transmit numerous kinds of viruses, bacteria, and protozoa between domestic animals.Rhabdomys: Rhabdomys is a largely Southern African genus of muroid rodents slightly larger than house mice. They are known variously as Striped or Four-Striped mice or rats.Belmont Park, Exeter: Belmont Park (also called Belmont Pleasure Grounds) is a public park in Exeter, England provided by Exeter City Council.Group A streptococcal infectionHuman mortality from H5N1: Human mortality from H5N1 or the human fatality ratio from H5N1 or the case-fatality rate of H5N1 refer to the ratio of the number of confirmed human deaths resulting from confirmed cases of transmission and infection of H5N1 to the number of those confirmed cases. For example, if there are 100 confirmed cases of humans infected with H5N1 and 10 die, then there is a 10% human fatality ratio (or mortality rate).Colt Crag Reservoir: Colt Crag Reservoir is a relatively shallow reservoir in Northumberland, England adjacent to the A68 road, and north of Corbridge. The A68 road at this point runs along the course of Dere Street, a Roman road.Distributed cache: In computing, a distributed cache is an extension of the traditional concept of cache used in a single locale. A distributed cache may span multiple servers so that it can grow in size and in transactional capacity.Yugoslavia at the 1972 Summer Paralympics: The Republic of Yugoslavia sent a delegation to compete at the 1972 Summer Paralympics in Heidelberg, West Germany. They sent twenty two competitors, fifteen male and seven female.Aedes aegyptiKocaeli University: The University of Kocaeli (KOU) is a state university in Kocaeli, Turkey. It was founded as the Academy of Engineering and Architecture of Kocaeli in 1976.Haemaphysalis longicornis: Haemaphysalis longicornis is a species of tick. Lyme spirochetes and spotted fever group rickettsiae have been detected in H.Coffee production in Angola: Coffee production in Angola refers to the production of coffee in Angola. Coffee is one of Angola's largest agricultural productsC. J. Peters: Clarence James Peters, Jr, M.D.New Mexico Livestock Board: The New Mexico Livestock Board regulates livestock health and livestock identification in New Mexico, in the United States. It was created in 1967 by the merger of the New Mexico Cattle Sanitary Board and the New Mexico Sheep Sanitary Board.Theodor Bilharz Research Institute: The Theodor Bilharz Research Institute is located in Giza, Egypt.Branching order of bacterial phyla (Gupta, 2001): There are several models of the Branching order of bacterial phyla, one of these was proposed in 2001 by Gupta based on conserved indels or protein, termed "protein signatures", an alternative approach to molecular phylogeny. Some problematic exceptions and conflicts are present to these conserved indels, however, they are in agreement with several groupings of classes and phyla.Wat Chiang ManCarte Jaune: The Carte Jaune or Yellow Card is an international certificate of vaccination (ICV). It is issued by the World Health Organisation.SeroconversionSeroprevalence: Seroprevalence is the number of persons in a population who test positive for a specific disease based on serology (blood serum) specimens; often presented as a percent of the total specimens tested or as a proportion per 100,000 persons tested. As positively identifying the occurrence of disease is usually based upon the presence of antibodies for that disease (especially with viral infections such as Herpes Simplex and HIV), this number is not significant if the specificity of the antibody is low.Tick-borne encephalitis virus: Tick-borne encephalitis virus (TBEV) is the virus associated with tick-borne encephalitis.Ditch: A ditch is a small to moderate depression created to channel water. A ditch can be used for drainage, to drain water from low-lying areas, alongside roadways or fields, or to channel water from a more distant source for plant irrigation.Co-option (biology)Tick-borne disease: Tick-borne diseases, which afflict humans and other animals, are caused by infectious agents transmitted by tick bites. Tick-borne illnesses are caused by infection with a variety of pathogens, including rickettsia and other types of bacteria, viruses, and protozoa.Boutonneuse feverImmunoglobulin C2-set domain: A:317–388 B:317–388 B:317–388Eva Engvall: Eva Engvall, born 1940, is one of the scientists who invented ELISA in 1971.Eva Engvall, The Scientist 1995, 9(18):8Togavirus 5' plus strand cis-regulatory elementH. R. Cox: Herald Rea Cox (1907–1986) was an American bacteriologist. The bacterial family Coxiellaceae and the genus Coxiella, which include the organism that causes Q fever, are named after him.RibavirinAntiviral drug: Antiviral drugs are a class of medication used specifically for treating viral infections. Like antibiotics for bacteria, specific antivirals are used for specific viruses.Staphylococcus microti: Staphylococcus microti is a Gram positive, coagulase-negative member of the bacterial genus Staphylococcus consisting of clustered cocci. This species was originally isolated from viscera of the common vole, Microtus arvalis.List of notifiable diseases: The following is a list of notifiable diseases arranged by country.Layout of the Port of Tianjin: The Port of Tianjin is divided into nine areas: the three core (“Tianjin Xingang”) areas of Beijiang, Nanjiang, and Dongjiang around the Xingang fairway; the Haihe area along the river; the Beitang port area around the Beitangkou estuary; the Dagukou port area in the estuary of the Haihe River; and three areas under construction (Hanggu, Gaoshaling, Nangang).TPCN2: Two pore segment channel 2 (TPC2) is a human protein encoded by the TPCN2 is a protein which in humans is encoded by the TPCN2 gene. TPC2 is an ion channel, however, in contrast to other calcium and sodium channels which have four homologous domains, each containing 6 transmembrane segments (S1 to S6), TPCN1 only contains two domain (each containing segments S1 to S6).Four Seasons Baltimore and Residences: Four Seasons Hotel Baltimore is currently a 22 story highrise hotel complex building which opened on November 14, 2011. The building's construction began back in 2007 and went through several changes.Coles PhillipsSchmallenberg virus: Schmallenberg virus is the informal name given to a recently isolated orthobunyavirus, which has not been given a formal name , initially reported in November 2011 to cause congenital malformations and stillbirths in cattle, sheep, goats, and possibly alpaca. It appears to be transmitted by midges (Culicoides spp.List of butterflies of Mauritania: This is a list of butterflies of Mauritania. About 30 species are known from Mauritania,African Butterfly Database none of which is endemic.Transport in South Sudan: == Highways ==
(1/111) Filoviral haemorrhagic fevers.
Sensationalised accounts of wards of dying patients have fueled intense public fascination with filoviruses and highlighted the global threat of emerging and re-emerging infectious diseases. Filoviruses are the prototypical emerging pathogens: they cause a haemorrhagic disease of high case-fatality associated with explosive outbreaks due to person-to-person transmission, have no known treatment, occur unpredictably, and have an unknown reservoir. In truth, since their initial discovery in 1967, only a handful of filoviral outbreaks have occurred, mostly in remote locations. However, the documented occurrence of secondary cases in locations far from endemic areas validates the concern that filoviruses have the potential to cause unprecedented outbreaks in the future. (+info)
(2/111) Ebola virus: a comparison, at ultrastructural level, of the behaviour of the Sudan and Zaire strains in monkeys.
Histopathological and electron microscopical examination of human liver specimens collected during the Ebola haemorrhagic fever outbreaks in Zaire and Sudan indicated that Zairean strains of the virus produced more extensive lesions. Experimental infection of rhesus monkeys wiht Zairean and Sudanese strains of Ebola virus produced similar changes to those found in man. In Zairean strain infections large numbers of virus particles were found in the liver, lung and spleen accompanied by extensive necrosis in the spleen. In Sudan strain infections particles were found only in the liver and in greatly reduced numbers. The main distinction lay in the high proportion of aberrant particles found with the Sudanese strain. The possibility of these being defective particles is discussed. (+info)
(3/111) Clinical and epidemiological patterns of Argentine haemorrhagic fever.
The epidemiology of Argentine haemorrhagic fever (AHF) is closely related to cricetine rodents acting as natural hosts of Junin virus. The endemo-epidemic area, which has increased 5 times since the disease was first recognized 15-20 years ago, is located in a densely populated region of Argentina. It has been shown that the virus of LCM is active in humans and rodents of the AHF endemic area; this demonstrates the simultaneous presence of two arenaviruses pathogenic for man in a given geographic location.The disease is characterized by haematological, renal, neurological and cardiovascular changes. Electron microscopy and immunohistochemical studies have shown cytopathic changes, characteristic intracellular virus-like particles, and antigenic determinants of Junin virus in different organs from 9 cases of AHF. No deposits of immunoglobulins or C3 were found in the kidneys; in addition, an absence of fibrinogen and C3 in the hepatocytes and of immunoglobulins in the spleen was observed. These findings suggest a direct viral pathogenic action in the human disease.Ultrastructural and immunofluorescence studies in tissues of guinea-pigs inoculated with two strains of Junin virus revealed the presence of the same types of virus-like particles and antigenic determinants of Junin virus as were encountered in the human subjects with AHF. (+info)
(4/111) Arenavirus chemotherapy--retrospect and prospect.
Two groups of compounds, identifiable by structural similarity, have been found to interfere with the in vitro replication of arenaviruses. All 4 members of the benzimidazole group contain dipolar fused benzene and 5-membered nitrogen-containing rings and share potential chelating ability through the different bidentate structures formed with their side-chains. The biological activity of one of these compounds, metisazone, has been shown to depend on the presence of divalent metals of the first transition series, Cu(++) being the most effective. Furthermore, whereas metisazone inactivates cell-free virus, two other members of the group, HBB and 1,2-bis(5-methoxy-1H-benzimidazol-2-yl)-1,2-ethanediol, act intracellularly. The site of action of the fourth member, SKF 30097, is not known. Using murine lymphocytic choriomeningitis infections as an in vivo model, the bisbenzimidazole derivative has been found to increase life-span without interfering with virus replication. Medication with SKF 30097 or metisazone and copper (2(+)) sulfate did not significantly or reproducibly change the expected day of death of the animals. The amantadine compounds of the second group have unusual symmetric structures with a 10-carbon cage. The parent compound acts intracellularly, while the site of action of an octachloro derivative is not known. Medication with the parent compound, but not the derivative, shortened the interval between LCM infection and death of the mouse. Tissue culture and animal screening of the many available derivatives in these two groups may uncover compounds more efficacious than those already examined. (+info)
(5/111) Directions for future research on the pathogenesis of arenaviral infections.
The pathogenesis of arenavirus infection is considered separately for the haemorrhagic fever (HF) syndrome and for lymphocytic choriomeningitis (LCM) virus infection of rodents. Experimental models of HF have received only limited study, mainly because of the virulence of the causal agents. Two useful models (Junin virus in guinea-pigs and Machupo virus in rhesus monkeys) are now available and an attempt is made to delineate crucial questions for future studies, including the physiology of shock, disseminated intravascular coagulation, immune mediation of disease, efficacy of antibody in treatment, and relative utility of attenuated and inactivated vaccines. Immunobiologic problems currently under investigation in LCM virus infection include the mechanism of immune destruction of infected tissues, the H-2 restriction of in vitro T-cell-mediated lysis of infected target cells, the transient immunodepression that accompanies acute primary LCM virus infection, and the mechanism of T-cell-mediated clearance of virus from infected tissues following adoptive immunization of persistently infected carrier mice. (+info)
(6/111) Viral hemorrhagic fever hazards for travelers in Africa.
This short review covers 6 viral hemorrhagic fevers (VHFs) that are known to occur in Africa: yellow fever, Rift Valley fever, Crimean-Congo hemorrhagic fever, Lassa fever, Marburg virus disease, and Ebola hemorrhagic fever. All of these have at one time or another affected travelers, often the adventurous kind who are "roughing it" in rural areas, who should therefore be made aware by their physicians or travel health clinics about their potential risk of exposure to any VHF along their travel route and how to minimize the risk. A significant proportion of VHF cases involving travelers have affected expatriate health care workers who were nosocomially exposed in African hospitals or clinics. The VHFs are associated with a high case-fatality rate but are readily prevented by well-known basic precautions. (+info)
(7/111) Isolation of ribosome-like sturctures from Pichinde virus.
Three classes of mamalian ribosome-like structures were found to be associated with purified Pichinde virus preparations. These structures, possessing sedimentation coefficients of 80S, 60S and 40S, were sensitive to EDTA dissociation and possessed a buoyant density in caesium chloride of 1-61 g/ml, a value analogous to that displayed by BHK21 cell ribosomes. Analyses of RNA components associated with ribosomal particles of Pichinde virus established that 28S and 18S RNAs could be extracted from 80S monosomes. Similarly, 28S and 18S RNAs were derived, respectively, from 60S and 30S ribosomal subunits. Virus-specific 31S and 22S RNAs, as well as 28S and 18S RNAs, could be isolated from the heavy region of sucrose gradients. An additional 15S type of RNA, which was subsequently shown to be a component of intact virus particles, was also isolated from the heavy region. (+info)
(8/111) Recognition of illness associated with the intentional release of a biologic agent.
On September 11, 2001, following the terrorist incidents in New York City and Washington, D.C., CDC recommended heightened surveillance for any unusual disease occurrence or increased numbers of illnesses that might be associated with the terrorist attacks. Subsequently, cases of anthrax in Florida and New York City have demonstrated the risks associated with intentional release of biologic agents. This report provides guidance for health-care providers and public health personnel about recognizing illnesses or patterns of illnessthat might be associated with intentional release of biologic agents. (+info)