Disease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Cholera: An acute diarrheal disease endemic in India and Southeast Asia whose causative agent is VIBRIO CHOLERAE. This condition can lead to severe dehydration in a matter of hours unless quickly treated.Influenza, Human: An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.Keratoconjunctivitis: Simultaneous inflammation of the cornea and conjunctiva.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)HIV Infections: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).Communicable DiseasesDisease Transmission, Infectious: The transmission of infectious disease or pathogens. When transmission is within the same species, the mode can be horizontal or vertical (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).Basic Reproduction Number: The expected number of new cases of an infection caused by an infected individual, in a population consisting of susceptible contacts only.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.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Porcine epidemic diarrhea virus: A species of CORONAVIRUS causing acute enteritis in swine. Infections have been seen mostly in Europe, where it is endemic, and in China.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.Quarantine: Restriction of freedom of movement of individuals who have been exposed to infectious or communicable disease in order to prevent its spread; a period of detention of vessels, vehicles, or travelers coming from infected or suspected places; and detention or isolation on account of suspected contagion. It includes government regulations on the detention of animals at frontiers or ports of entrance for the prevention of infectious disease, through a period of isolation before being allowed to enter a country. (From Dorland, 28th ed & Black's Veterinary Dictionary, 17th ed)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.Space-Time Clustering: A statistically significant excess of cases of a disease, occurring within a limited space-time continuum.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.Communicable Diseases, Emerging: Infectious diseases that are novel in their outbreak ranges (geographic and host) or transmission mode.Sentinel Surveillance: Monitoring of rate of occurrence of specific conditions to assess the stability or change in health levels of a population. It is also the study of disease rates in a specific cohort such as in a geographic area or population subgroup to estimate trends in a larger population. (From Last, Dictionary of Epidemiology, 2d ed)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.Meningitis, Meningococcal: A fulminant infection of the meninges and subarachnoid fluid by the bacterium NEISSERIA MENINGITIDIS, producing diffuse inflammation and peri-meningeal venous thromboses. Clinical manifestations include FEVER, nuchal rigidity, SEIZURES, severe HEADACHE, petechial rash, stupor, focal neurologic deficits, HYDROCEPHALUS, and COMA. The organism is usually transmitted via nasopharyngeal secretions and is a leading cause of meningitis in children and young adults. Organisms from Neisseria meningitidis serogroups A, B, C, Y, and W-135 have been reported to cause meningitis. (From Adams et al., Principles of Neurology, 6th ed, pp689-701; Curr Opin Pediatr 1998 Feb;10(1):13-8)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.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.Foot-and-Mouth DiseaseModels, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.History, 20th Century: Time period from 1901 through 2000 of the common era.Acquired Immunodeficiency Syndrome: An acquired defect of cellular immunity associated with infection by the human immunodeficiency virus (HIV), a CD4-positive T-lymphocyte count under 200 cells/microliter or less than 14% of total lymphocytes, and increased susceptibility to opportunistic infections and malignant neoplasms. Clinical manifestations also include emaciation (wasting) and dementia. These elements reflect criteria for AIDS as defined by the CDC in 1993.Weather: The state of the ATMOSPHERE over minutes to months.Haiti: A republic in the Greater Antilles in the West Indies. Its capital is Port-au-Prince. With the Dominican Republic it forms the island of Hispaniola - Haiti occupying the western third and the Dominican Republic, the eastern two thirds. Haiti belonged to France from 1697 until its rule was challenged by slave insurrections from 1791. It became a republic in 1820. It was virtually an American protectorate from 1915 to 1934. It adopted its present constitution in 1964 and amended it in 1971. The name may represent either of two Caribbean words, haiti, mountain land, or jhaiti, nest. (From Webster's New Geographical Dictionary, 1988, p481 & Room, Brewer's Dictionary of Names, 1992, p225)World Health: The concept pertaining to the health status of inhabitants of the world.Influenza A Virus, H1N1 Subtype: A subtype of INFLUENZA A VIRUS with the surface proteins hemagglutinin 1 and neuraminidase 1. The H1N1 subtype was responsible for the Spanish flu pandemic of 1918.Stochastic Processes: Processes that incorporate some element of randomness, used particularly to refer to a time series of random variables.Diphtheria: A localized infection of mucous membranes or skin caused by toxigenic strains of CORYNEBACTERIUM DIPHTHERIAE. It is characterized by the presence of a pseudomembrane at the site of infection. DIPHTHERIA TOXIN, produced by C. diphtheriae, can cause myocarditis, polyneuritis, and other systemic toxic effects.China: A country spanning from central Asia to the Pacific Ocean.Vibrio cholerae: The etiologic agent of CHOLERA.Rain: Water particles that fall from the ATMOSPHERE.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Serotyping: Process of determining and distinguishing species of bacteria or viruses based on antigens they share.Severe Acute Respiratory Syndrome: A viral disorder characterized by high FEVER, dry COUGH, shortness of breath (DYSPNEA) or breathing difficulties, and atypical PNEUMONIA. A virus in the genus CORONAVIRUS is the suspected agent.Models, Statistical: Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.Cluster Analysis: A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.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.Electrophoresis, Gel, Pulsed-Field: Gel electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.Climate: The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)History, 19th Century: Time period from 1801 through 1900 of the common era.Cross Infection: Any infection which a patient contracts in a health-care institution.Public Health: Branch of medicine concerned with the prevention and control of disease and disability, and the promotion of physical and mental health of the population on the international, national, state, or municipal level.Burundi: A republic in eastern Africa bounded on the north by RWANDA and on the south by TANZANIA. Its capital is Bujumbura.History, 18th Century: Time period from 1701 through 1800 of the common era.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)United StatesGenotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Insect Vectors: Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Disease Notification: Notification or reporting by a physician or other health care provider of the occurrence of specified contagious diseases such as tuberculosis and HIV infections to designated public health agencies. The United States system of reporting notifiable diseases evolved from the Quarantine Act of 1878, which authorized the US Public Health Service to collect morbidity data on cholera, smallpox, and yellow fever; each state in the US has its own list of notifiable diseases and depends largely on reporting by the individual health care provider. (From Segen, Dictionary of Modern Medicine, 1992)Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Adenovirus Infections, Human: Respiratory and conjunctival infections caused by 33 identified serotypes of human adenoviruses.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.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)Epidemiology: Field of medicine concerned with the determination of causes, incidence, and characteristic behavior of disease outbreaks affecting human populations. It includes the interrelationships of host, agent, and environment as related to the distribution and control of disease.Pleurodynia, Epidemic: An acute, febrile, infectious disease generally occurring in epidemics. It is usually caused by coxsackieviruses B and sometimes by coxsackieviruses A; echoviruses; or other enteroviruses.Time Factors: Elements of limited time intervals, contributing to particular results or situations.History, 17th Century: Time period from 1601 through 1700 of the common era.Public Health Surveillance: The ongoing, systematic collection, analysis, and interpretation of health-related data with the purpose of preventing or controlling disease or injury, or of identifying unusual events of public health importance, followed by the dissemination and use of information for public health action. (From Am J Prev Med 2011;41(6):636)IndiaAfricaPandemics: Epidemics of infectious disease that have spread to many countries, often more than one continent, and usually affecting a large number of people.History, 16th Century: Time period from 1501 through 1600 of the common era.Vibrio cholerae O1: Strains of VIBRIO CHOLERAE containing O ANTIGENS group 1. All are CHOLERA-causing strains (serotypes). There are two biovars (biotypes): cholerae and eltor (El Tor).Bacterial Typing Techniques: Procedures for identifying types and strains of bacteria. The most frequently employed typing systems are BACTERIOPHAGE TYPING and SEROTYPING as well as bacteriocin typing and biotyping.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.Africa South of the Sahara: All of Africa except Northern Africa (AFRICA, NORTHERN).Vaccination: Administration of vaccines to stimulate the host's immune response. This includes any preparation intended for active immunological prophylaxis.Genetic Variation: Genotypic differences observed among individuals in a population.Substance Abuse, Intravenous: Abuse, overuse, or misuse of a substance by its injection into a vein.Corynebacterium diphtheriae: A species of gram-positive, asporogenous bacteria in which three cultural types are recognized. These types (gravis, intermedius, and mitis) were originally given in accordance with the clinical severity of the cases from which the different strains were most frequently isolated. This species is the causative agent of DIPHTHERIA.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.Rickettsia prowazekii: A species of gram-negative, aerobic bacteria that is the etiologic agent of epidemic typhus fever acquired through contact with lice (TYPHUS, EPIDEMIC LOUSE-BORNE) as well as Brill's disease.Distemper Virus, Phocine: A species of MORBILLIVIRUS causing distemper in seals.Infant, Newborn: An infant during the first month after birth.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.Norovirus: A genus in the family CALICIVIRIDAE, associated with epidemic GASTROENTERITIS in humans. The type species, NORWALK VIRUS, contains multiple strains.History, 15th Century: Time period from 1401 through 1500 of the common era.History, 21st Century: Time period from 2001 through 2100 of the common era.Sexual Behavior: Sexual activities of humans.South Africa: A republic in southern Africa, the southernmost part of Africa. It has three capitals: Pretoria (administrative), Cape Town (legislative), and Bloemfontein (judicial). Officially the Republic of South Africa since 1960, it was called the Union of South Africa 1910-1960.Homosexuality, Male: Sexual attraction or relationship between males.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)Epidemiologic Factors: Events, characteristics, or other definable entities that have the potential to bring about a change in a health condition or other defined outcome.Echovirus Infections: Infectious disease processes, including meningitis, diarrhea, and respiratory disorders, caused by echoviruses.Obesity: A status with BODY WEIGHT that is grossly above the acceptable or desirable weight, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).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)BrazilRibotyping: RESTRICTION FRAGMENT LENGTH POLYMORPHISM analysis of rRNA genes that is used for differentiating between species or strains.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Plague: An acute infectious disease caused by YERSINIA PESTIS that affects humans, wild rodents, and their ectoparasites. This condition persists due to its firm entrenchment in sylvatic rodent-flea ecosystems throughout the world. Bubonic plague is the most common form.Travel: Aspects of health and disease related to travel.Influenza A virus: The type species of the genus INFLUENZAVIRUS A that causes influenza and other diseases in humans and animals. Antigenic variation occurs frequently between strains, allowing classification into subtypes and variants. Transmission is usually by aerosol (human and most non-aquatic hosts) or waterborne (ducks). Infected birds shed the virus in their saliva, nasal secretions, and feces.Neisseria meningitidis, Serogroup W-135: Strains of Neisseria meningitidis found mostly in Africa.Influenza A Virus, H3N2 Subtype: A subtype of INFLUENZA A VIRUS comprised of the surface proteins hemagglutinin 3 and neuraminidase 2. The H3N2 subtype was responsible for the Hong Kong flu pandemic of 1968.Conjunctivitis, Viral: Inflammation, often mild, of the conjunctiva caused by a variety of viral agents. Conjunctival involvement may be part of a systemic infection.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.Antibodies, Viral: Immunoglobulins produced in response to VIRAL ANTIGENS.Epidemiologic Methods: Research techniques that focus on study designs and data gathering methods in human and animal populations.Hand, Foot and Mouth Disease: A mild, highly infectious viral disease of children, characterized by vesicular lesions in the mouth and on the hands and feet. It is caused by coxsackieviruses A.DNA Fingerprinting: A technique for identifying individuals of a species that is based on the uniqueness of their DNA sequence. Uniqueness is determined by identifying which combination of allelic variations occur in the individual at a statistically relevant number of different loci. In forensic studies, RESTRICTION FRAGMENT LENGTH POLYMORPHISM of multiple, highly polymorphic VNTR LOCI or MICROSATELLITE REPEAT loci are analyzed. The number of loci used for the profile depends on the ALLELE FREQUENCY in the population.Influenza Vaccines: Vaccines used to prevent infection by viruses in the family ORTHOMYXOVIRIDAE. It includes both killed and attenuated vaccines. The composition of the vaccines is changed each year in response to antigenic shifts and changes in prevalence of influenza virus strains. The vaccine is usually bivalent or trivalent, containing one or two INFLUENZAVIRUS A strains and one INFLUENZAVIRUS B strain.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.ConjunctivitisTajikistanHIV Seroprevalence: Studies of the number of cases where human immunodeficiency virus (HIV) is present in a specific population at a designated time. The presence in a given individual is determined by the finding of HIV antibodies in the serum (HIV SEROPOSITIVITY).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.Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Gastroenteritis: INFLAMMATION of any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM. Causes of gastroenteritis are many including genetic, infection, HYPERSENSITIVITY, drug effects, and CANCER.USSRCulicidae: 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.Age Distribution: The frequency of different ages or age groups in a given population. The distribution may refer to either how many or what proportion of the group. The population is usually patients with a specific disease but the concept is not restricted to humans and is not restricted to medicine.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.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.Influenza B virus: Species of the genus INFLUENZAVIRUS B that cause HUMAN INFLUENZA and other diseases primarily in humans. Antigenic variation is less extensive than in type A viruses (INFLUENZA A VIRUS) and consequently there is no basis for distinct subtypes or variants. Epidemics are less likely than with INFLUENZA A VIRUS and there have been no pandemics. Previously only found in humans, Influenza B virus has been isolated from seals which may constitute the animal reservoir from which humans are exposed.Influenza in Birds: Infection of domestic and wild fowl and other BIRDS with INFLUENZA A VIRUS. Avian influenza usually does not sicken birds, but can be highly pathogenic and fatal in domestic POULTRY.Neisseria meningitidis, Serogroup A: Strains of Neisseria meningitidis responsible for most outbreaks of meningococcal disease in Western Europe and the United States in the first half of the 20th century. They continue to be a major cause of disease in Asia and Africa, and especially localized epidemics in Sub-Sahara Africa.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.Mass Vaccination: Administration of a vaccine to large populations in order to elicit IMMUNITY.Public Health Practice: The activities and endeavors of the public health services in a community on any level.Africa, Eastern: The geographical area of Africa comprising BURUNDI; DJIBOUTI; ETHIOPIA; KENYA; RWANDA; SOMALIA; SUDAN; TANZANIA; and UGANDA.Caliciviridae Infections: Virus diseases caused by CALICIVIRIDAE. They include HEPATITIS E; VESICULAR EXANTHEMA OF SWINE; acute respiratory infections in felines, rabbit hemorrhagic disease, and some cases of gastroenteritis in humans.JapanRussiaDemocratic 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.Forecasting: The prediction or projection of the nature of future problems or existing conditions based upon the extrapolation or interpretation of existing scientific data or by the application of scientific methodology.Population Dynamics: The pattern of any process, or the interrelationship of phenomena, which affects growth or change within a population.Epidemiological Monitoring: Collection, analysis, and interpretation of data about the frequency, distribution, and consequences of disease or health conditions, for use in the planning, implementing, and evaluating public health programs.Vibrio cholerae O139: Strains of VIBRIO CHOLERAE containing O ANTIGENS group 139. This strain emerged in India in 1992 and caused a CHOLERA epidemic.Great BritainPatient 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.Zimbabwe: A republic in southern Africa, east of ZAMBIA and BOTSWANA and west of MOZAMBIQUE. Its capital is Harare. It was formerly called Rhodesia and Southern Rhodesia.Phoca: A genus in the family of EARLESS SEALS (Phocidae) and collectively the most abundant PINNIPEDS in the Northern Hemisphere.France: A country in western Europe bordered by the Atlantic Ocean, the English Channel, the Mediterranean Sea, and the countries of Belgium, Germany, Italy, Spain, Switzerland, the principalities of Andorra and Monaco, and by the duchy of Luxembourg. Its capital is Paris.Neisseria meningitidis: A species of gram-negative, aerobic BACTERIA. It is a commensal and pathogen only of humans, and can be carried asymptomatically in the NASOPHARYNX. When found in cerebrospinal fluid it is the causative agent of cerebrospinal meningitis (MENINGITIS, MENINGOCOCCAL). It is also found in venereal discharges and blood. There are at least 13 serogroups based on antigenic differences in the capsular polysaccharides; the ones causing most meningitis infections being A, B, C, Y, and W-135. Each serogroup can be further classified by serotype, serosubtype, and immunotype.History, Medieval: The period of history from the year 500 through 1450 of the common era.Thailand: Formerly known as Siam, this is a Southeast Asian nation at the center of the Indochina peninsula. Bangkok is the capital city.Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Staphylococcal Infections: Infections with bacteria of the genus STAPHYLOCOCCUS.Methicillin Resistance: Non-susceptibility of a microbe to the action of METHICILLIN, a semi-synthetic penicillin derivative.Zoonoses: Diseases of non-human animals that may be transmitted to HUMANS or may be transmitted from humans to non-human animals.Demography: Statistical interpretation and description of a population with reference to distribution, composition, or structure.UkrainePoultry: Domesticated birds raised for food. It typically includes CHICKENS; TURKEYS, DUCKS; GEESE; and others.Niger: A republic in western Africa, north of NIGERIA and west of CHAD. Its capital is Niamey.Bacteriophage Typing: A technique of bacterial typing which differentiates between bacteria or strains of bacteria by their susceptibility to one or more bacteriophages.Diphtheria Toxoid: The formaldehyde-inactivated toxin of Corynebacterium diphtheriae. It is generally used in mixtures with TETANUS TOXOID and PERTUSSIS VACCINE; (DTP); or with tetanus toxoid alone (DT for pediatric use and Td, which contains 5- to 10-fold less diphtheria toxoid, for other use). Diphtheria toxoid is used for the prevention of diphtheria; DIPHTHERIA ANTITOXIN is for treatment.Enterovirus InfectionsAnti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Spatio-Temporal Analysis: Techniques which study entities using their topological, geometric, or geographic properties and include the dimension of time in the analysis.Virulence: The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.Commonwealth of Independent StatesSanitation: The development and establishment of environmental conditions favorable to the health of the public.Conjunctivitis, Acute Hemorrhagic: A highly contagious disease characterized by subconjunctival hemorrhage, sudden swelling of the eyelids and congestion, redness, and pain in the eye. Epidemic conjunctivitis caused by Enterovirus 70 (EV-70) was first described in Africa in 1969. It is caused also by Coxsackievirus A24 variant (CA24v). Epidemics by this organism have appeared most frequently in Asia.HIV-1: The type species of LENTIVIRUS and the etiologic agent of AIDS. It is characterized by its cytopathic effect and affinity for the T4-lymphocyte.Multilocus Sequence Typing: Direct nucleotide sequencing of gene fragments from multiple housekeeping genes for the purpose of phylogenetic analysis, organism identification, and typing of species, strain, serovar, or other distinguishable phylogenetic level.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.Guinea-Bissau: A republic in western Africa, south of SENEGAL and west of GUINEA. Its capital is Bissau.Hemagglutination 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.Health Policy: Decisions, usually developed by government policymakers, for determining present and future objectives pertaining to the health care system.ItalyKenya: 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.Heterosexuality: The sexual attraction or relationship between members of the opposite SEX.RNA, Viral: Ribonucleic acid that makes up the genetic material of viruses.Hong Kong: The former British crown colony located off the southeast coast of China, comprised of Hong Kong Island, Kowloon Peninsula, and New Territories. The three sites were ceded to the British by the Chinese respectively in 1841, 1860, and 1898. Hong Kong reverted to China in July 1997. The name represents the Cantonese pronunciation of the Chinese xianggang, fragrant port, from xiang, perfume and gang, port or harbor, with reference to its currents sweetened by fresh water from a river west of it.Genome, Viral: The complete genetic complement contained in a DNA or RNA molecule in a virus.Clostridium difficile: A common inhabitant of the colon flora in human infants and sometimes in adults. It produces a toxin that causes pseudomembranous enterocolitis (ENTEROCOLITIS, PSEUDOMEMBRANOUS) in patients receiving antibiotic therapy.EuropeSexually Transmitted Diseases: Diseases due to or propagated by sexual contact.Uganda: A republic in eastern Africa, south of SUDAN and west of KENYA. Its capital is Kampala.Africa, Central: The geographical area of Africa comprising CAMEROON; CENTRAL AFRICAN REPUBLIC; CHAD; CONGO; EQUATORIAL GUINEA; GABON; and DEMOCRATIC REPUBLIC OF THE CONGO.pol Gene Products, Human Immunodeficiency Virus: Proteins encoded by the POL GENE of the HUMAN IMMUNODEFICIENCY VIRUS.Meningococcal Infections: Infections with bacteria of the species NEISSERIA MENINGITIDIS.Rural Population: The inhabitants of rural areas or of small towns classified as rural.Staphylococcus aureus: Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications.RomaniaUnited Nations: An international organization whose members include most of the sovereign nations of the world with headquarters in New York City. The primary objectives of the organization are to maintain peace and security and to achieve international cooperation in solving international economic, social, cultural, or humanitarian problems.West Nile Fever: A mosquito-borne viral illness caused by the WEST NILE VIRUS, a FLAVIVIRUS and endemic to regions of Africa, Asia, and Europe. Common clinical features include HEADACHE; FEVER; maculopapular rash; gastrointestinal symptoms; and lymphadenopathy. MENINGITIS; ENCEPHALITIS; and MYELITIS may also occur. The disease may occasionally be fatal or leave survivors with residual neurologic deficits. (From Joynt, Clinical Neurology, 1996, Ch26, p13; Lancet 1998 Sep 5;352(9130):767-71)Animal DiseasesRisk-Taking: Undertaking a task involving a challenge for achievement or a desirable goal in which there is a lack of certainty or a fear of failure. It may also include the exhibiting of certain behaviors whose outcomes may present a risk to the individual or to those associated with him or her.TaiwanBangladeshDisease Vectors: Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.Population Density: Number of individuals in a population relative to space.Burkholderia Infections: Infections with bacteria of the genus BURKHOLDERIA.Africa, Southern: The geographical area of Africa comprising ANGOLA; BOTSWANA; LESOTHO; MALAWI; MOZAMBIQUE; NAMIBIA; SOUTH AFRICA; SWAZILAND; ZAMBIA; and ZIMBABWE.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.Immunity, Herd: The non-susceptibility to infection of a large group of individuals in a population. A variety of factors can be responsible for herd immunity and this gives rise to the different definitions used in the literature. Most commonly, herd immunity refers to the case when, if most of the population is immune, infection of a single individual will not cause an epidemic. Also, in such immunized populations, susceptible individuals are not likely to become infected. Herd immunity can also refer to the case when unprotected individuals fail to contract a disease because the infecting organism has been banished from the population.MexicoCoronavirus Infections: Virus diseases caused by the CORONAVIRUS genus. Some specifics include transmissible enteritis of turkeys (ENTERITIS, TRANSMISSIBLE, OF TURKEYS); FELINE INFECTIOUS PERITONITIS; and transmissible gastroenteritis of swine (GASTROENTERITIS, TRANSMISSIBLE, OF SWINE).Molecular Typing: Using MOLECULAR BIOLOGY techniques, such as DNA SEQUENCE ANALYSIS; PULSED-FIELD GEL ELECTROPHORESIS; and DNA FINGERPRINTING, to identify, classify, and compare organisms and their subtypes.Orthomyxoviridae: A family of RNA viruses causing INFLUENZA and other diseases. There are five recognized genera: INFLUENZAVIRUS A; INFLUENZAVIRUS B; INFLUENZAVIRUS C; ISAVIRUS; and THOGOTOVIRUS.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.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.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.Kuru: A prion disease found exclusively among the Fore linguistic group natives of the highlands of NEW GUINEA. The illness is primarily restricted to adult females and children of both sexes. It is marked by the subacute onset of tremor and ataxia followed by motor weakness and incontinence. Death occurs within 3-6 months of disease onset. The condition is associated with ritual cannibalism, and has become rare since this practice has been discontinued. Pathologic features include a noninflammatory loss of neurons that is most prominent in the cerebellum, glial proliferation, and amyloid plaques. (From Adams et al., Principles of Neurology, 6th ed, p773)