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Appendix D Glossary Acquired immune deficiency syndrome (AIDS): An infectious disease caused by the human immunodeficiency virus (HIV). There are two variants of the HIV virus, HIV-1 and HIV-2, both of which ultimately cause AIDS. Agent (of disease): Factor such as a microorganism whose presence is essential for the occurrence of a disease. Anophelines: A genus of mosquitoes that includes all mosquitoes that transmit malaria to humans. Anthropogenic: Caused or produced by humans. Anthroponotic: Transmission from human to human and potentially from hu- man to animal. Antibiotic: Class of substances that can kill or inhibit the growth of some groups of microorganisms. Used in this report to refer to chemicals active against bacte- ria. Originally antibiotics were derived from natural sources (e.g., penicillin from molds), but many currently used antibiotics are semisynthetic and modified with additions of man-made chemical components. See antimicrobials. Antibiotic resistance: Property of bacteria that confers the capacity to inactivate or exclude antibiotics or a mechanism that blocks the inhibitory or killing effects of antibiotics. 399
400 GLOBAL CHANGE AND INFECTIOUS DISEASE DYNAMICS Antimicrobials: Class of substances that can destroy or inhibit the growth of pathogenic groups of microorganisms, including bacteria, viruses, parasites, and fungi. Arboviral diseases: Shortened form of arthropod-borne virus. Any of a group of viruses that are transmitted to man and animals by mosquitoes, ticks, and sand flies; they include such agents as yellow fever and eastern, western, and Venezu- elan equine encephalitis viruses. Arthropod: Any of a phylum (Arthropoda) of invertebrate animals (as insects, arachnids, and crustaceans) that have a segmented body and jointed appendages, a usually chitinous exoskeleton molted at intervals, and a dorsal anterior brain connected to a ventral chain of ganglia. Asymptomatic: Presenting no symptoms of disease. Bacteria: Microscopic, single-celled organisms that have some biochemical and structural features different from those of animal and plant cells. Biological weapon: A harmful biological agent (such as a pathogenic microor- ganism or a neurotoxin) used as a weapon to cause death or disease usually on a large scale. Biota: The animal and plant life of a given region. Bioterrorism: Terrorism involving use of biological warfare agents (as disease- causing viruses or herbicides). Botulism: A rare but serious paralytic illness caused by a nerve toxin. Symp- toms of botulism include double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth, and muscle weakness. The illness can cause paralysis, respiratory failure, and death. Bushmeat: Wildlife species that are hunted in the âbushâ or forests. Chemoprophylaxis: The use of drugs or biologics taken by asymptomatic per- sons to reduce the risk of developing a disease. Circumpolar region: The region that extends above 60Â° north latitude, borders the Arctic Ocean, and includes all, or the northern parts, of eight nations: the United States (Alaska), Canada, Greenland, Iceland, Norway, Finland, Sweden, and the Russian Federation.
APPENDIX D 401 Climate: Average meteorological conditions over a specified time period, usually at least 1 month, resulting from interactions among the atmosphere, oceans, and land surface. Climate variations occur over a wide range of spatial and temporal scales. Climate change: A change of climate that is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and that is in addition to natural climate variability observed over comparable time periods. Climate extremes: Used to represent weather extremes, but viewed over seasons (e.g., droughts) or longer periods. See extreme weather. Climate variability: Refers to variations or deviations from the mean state of the climate or temporal variations of the atmosphereâocean system around a mean state measure over a long period of time. Typically, this term is used for time scales longer than those associated with synoptic weather events (i.e., months to millennia and longer). The term natural climate variability is further used to identify climate variations that are not attributable to or influenced by any activ- ity related to humans. However, it is recognized that such âinternal or natural variabilityâ could be affected by external factors driving climate change such as changes in the atmospheric concentration of greenhouse gases. The El NiÃ±o- Southern Oscillation (ENSO) phenomena is a good example of the variability in the coupled oceanic and atmosphere system that is a central factor in short- term climate variability and the interannual time scale (http://www.cpc.noaa.gov/ products/analysis_monitoring/ensostuff/prelude_to_ensofaq.shtml; http://www. ncdc.noaa.gov/paleo/outreach/coral/coralenso.html; http://www.sws.uiuc.edu/ atmos/statecli/Climate_change/glossary.htm). Communicable disease: An infectious disease transmissible (as from person to person) by direct contact with an infected individual or the individualâs dis- charges or by indirect means (as by a vector). Disease: As used in this report, refers to a situation in which infection has elicited signs and symptoms in the infected individual; the infection has become clini- cally apparent. DNA (deoxyribonucleic acid): Any of various nucleic acids that are usually the molecular basis of heredity and are constructed of a double helix held together by hydrogen bonds between purine and pyrimidine bases that project inward from two chains containing alternate links of deoxyribose and phosphate, and that in eukaryotes are localized chiefly in cell nuclei.
402 GLOBAL CHANGE AND INFECTIOUS DISEASE DYNAMICS Ecology: The scientific study of the relationship between living things and their environments. Ecosystem: Mutually interrelated communities of species and abiotic compo- nents, existing as a system with specific interactions and exchange of matter, energy, and information. Ectoparasite: A parasite that lives on the exterior of its host. El NiÃ±o: A warming of the surface waters of the tropical Pacific that occurs every 3 to 5 years, temporarily affecting weather worldwide. Emerging infection: Either a newly recognized, clinically distinct infectious disease or a known infectious disease whose reported incidence is increasing in a given place or among a specific population. Emerging infections: Any infectious disease that has come to medical attention within the last two decades or for which there is a threat that its prevalence will increase in the near future. Many times, such diseases exist in nature as zoonoses and emerge as human pathogens only when humans come into contact with a formerly isolated animal population, such as monkeys in a rain forest that are no longer isolated because of deforestation. Drug-resistant organisms could also be included as the cause of emerging infections since they exist because of human influence. Some recent examples of agents responsible for emerging infections include human immunodeficiency virus, Ebola virus, multidrug-resistant Myco- bacterium tuberculosis, and influenza A(H1N1). Emerging infectious diseases: Infections that are rapidly increasing in incidence or geographic range. Emigration: To leave oneâs usual country of residence to settle in another. Endemic: Present in a community or common among a group of people; said of a disease prevailing continually in a region. Enteric: Of, relating to, or affecting the intestines. Enzootic: A disease of low morbidity that is constantly present in an animal community. Epidemic: The condition in which a disease spreads rapidly through a com- munity in which that disease is normally not present or is present at a low level.
APPENDIX D 403 Epidemiology: Study of the distribution and determinants of health-related states or events in specified populations. Epidemiology is the basic quantitative science of public health. Epizootic: A disease of high morbidity that is only occasionally present in an animal community. Eradication: Reduction of the worldwide incidence of a disease to zero as a result of deliberate efforts. Escherichia coli: A straight rod-shaped gram-negative bacterium that is used in public health as an indicator of fecal pollution (as of water or food) and in medi- cine and genetics as a research organism and that occurs in various strains that may live as harmless inhabitants of the human lower intestine or may produce a toxin causing intestinal illness. Etiology: Science and study of the causes of diseases and their mode of operation. Extreme weather: Refers to weather phenomena that are at the extremes of the historical distribution and are rare for a particular place and/or time, especially severe or unseasonal weather. Such extremes include severe thunderstorms, sever snowstorms, ice storms, blizzards, flooding, hurricanes, and high winds, and heat waves. For example, although flooding is common in the United States, the impacts of flooding are not consistent from year to year through time. Many years of small floods with little impact may be followed by a single large flood with a sizable loss (e.g., the June 2008 flooding in the Midwestern United States) (http://www.greenhouse.gov.au/impacts/resources/glossary.html; http:// en.wikipedia.org/wiki/Extreme_weather; http://www.sws.uiuc.edu/atmos/statecli/ General/Illinois-climate-narrative.htm). Extrinsic incubation period: Time required for the development of a disease agent in a vector from the time of uptake of the agent to the time the vector is infective. Food-borne diseases: Disease caused by consuming contaminated foods or beverages. Many different disease-causing microbes, or pathogens, can con- taminate foods, so there are many different food-borne infections. In addition, poisonous chemicals, or other harmful substances can cause food-borne dis- eases if they are present in food (http://www.cdc.gov/ncidod/dbmd/diseaseinfo/ foodborneinfections_g.htm).
404 GLOBAL CHANGE AND INFECTIOUS DISEASE DYNAMICS Genome: The complete set of genetic information in an organism. In bacteria, this includes the chromosome(s) and plasmids (extra-chromosomal DNA mol- ecules that can replicate autonomously within a bacterial cell). Genomics: The study of all the genes in a person, as well as interactions of those genes with each other and with that personâs environment (http://www.cdc.gov/ genomics/faq.htm). Global warming: The gradual increase, observed or projected, in global surface temperature, as one of the consequences of radiative forcing caused by anthro- pogenic emissions. Globalization: The increased interconnectedness and interdependence of peoples and countries is generally understood to include two interrelated elements: the opening of borders to increasingly fast flows of goods, services, finance, people, and ideas across international borders; and the changes in institutional and policy regimes at the international and national levels that facilitate or promote such flows (http://www.who.int/trade/glossary/story043/en/index.html). Host (disease): Person or other living animal that affords subsistence or lodgment to an infectious agent under natural conditions. Human immunodeficiency virus (HIV): A retrovirus that causes AIDS by in- fecting helper T cells of the immune system. The most common serotype, HIV-1, is distributed worldwide, while HIV-2 is primarily confined to West Africa. Immigration: To arrive and take up permanent residence in a country other than oneâs usual county of residence. Immune-competence: The ability of the immune system to respond appropri- ately to an antigenic stimulation. Incidence: Number of cases of a disease commencing, or of persons falling ill, during a given period of time in a specified population. Incidence rate is the number of new cases of a specific disease diagnosed or reported during a defined interval of time divided by the number of all persons in a defined population during the same time. Infection: The invasion of the body or a part of the body by a pathogenic agent, such as a microorganism or virus. Under favorable conditions the agent develops or multiplies, the results of which may produce injurious effects. Infection should not be confused with disease.
APPENDIX D 405 Intermediate host: A host that is normally used by a parasite in the course of its life cycle and in which it may multiply asexually but not sexually. International Health Regulations (IHR): An international legal instrument that is binding on 194 countries across the globe, including all the member states of WHO. Their aim is to help the international community prevent and respond to acute public health risks that have the potential to cross borders and threaten people worldwide. The IHR, which entered into force on June 15, 2007, requires countries to report certain disease outbreaks and public health events to WHO. Building on the unique experience of WHO in global disease surveillance, alert, and response, the IHR defines the rights and obligations of countries to report public health events, and establishes a number of procedures that WHO must follow in its work to uphold global public health security. La NiÃ±a: Cooler than normal sea surface temperatures in the central and eastern tropical Pacific ocean that impact global weather patterns. La NiÃ±a conditions recur every few years and can persist for as long as 2 years. Microbe: A microorganism or biologic agent that can replicate in humans (in- cluding bacteria, viruses, protozoa, fungi, and prions). Microbial threat: Microbes that lead to disease in humans. Microbiology: A branch of biology dealing especially with microscopic forms of life. Middle East respiratory syndrome: A viral respiratory illness first reported in Saudi Arabia in 2012. It is caused by a coronavirus called MERS-CoV. This par- ticular strain of coronavirus has not been previously identified in humans. There is very limited information on transmission, severity, and clinical impact with only a small number of cases reported thus far. Migration: The regular, usually seasonal, movement of all or part of an animal population to and from a given area. Millennium Development Goals: Eight international development goals that were established following the Millennium Summit of the United Nations in 2000, following the adoption of the United Nations Millennium Declaration. Mitigation: Initiatives that reduce the risk from natural and man-made hazards. With respect to climate change, mitigation usually refers to actions taken to re- duce the emissions or enhance the sinks of greenhouse gases.
406 GLOBAL CHANGE AND INFECTIOUS DISEASE DYNAMICS Monoculture: The cultivation or growth of a single crop or organism especially on agricultural or forest land. Morbidity: Diseased condition or state. Mortality: The number of deaths in a given time or place; the proportion of deaths to population. Outbreak: Localized occurrence as opposed to a generalized epidemic. Pandemic: Epidemic occurring over a wide geographic area and affecting an exceptionally high proportion of the population. Pathogen: Organism capable of causing disease. Pathogenic: Capable of causing disease. Pathology: The branch of medicine concerned with disease, especially its struc- ture and its functional effects on the body. Permafrost: Permanently frozen land. Phenology: The study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate, as well as habitat factors (such as elevation). Because many such phenomena are very sensitive to small variations in climate, especially to temperature, phenological records can be a useful proxy for temperature in historical climatology, especially in the study of climate change and global warming. For example, viticultural records of grape harvests in Europe have been used to reconstruct a record of summer growing season temperatures going back more than 500 years. In ad- dition to providing a longer historical baseline than instrumental measurements, phenological observations provide high temporal resolution of ongoing changes related to global warming. Phylogeny: The connections between all groups of organisms as understood by ancestor/descendant relationships. Polymerase chain reaction (PCR): A scientific technique in molecular biol- ogy to amplify a single or a few copies of a piece of DNA across several orders of magnitude, generating thousands to millions of copies of a particular DNA sequence.
APPENDIX D 407 Prevalence: Proportion of persons in a population currently affected by a par- ticular disease. Prevalence rate is the number of cases of a specific disease at a particular time divided by the population at that time living in the same region. Prophylaxis: Measures designed to preserve health (as of an individual or of society) and prevent the spread of disease. Quarantine: The enforced isolation or restriction of free movement imposed to prevent the spread of disease. Reservoir: Any person, animal, arthropod, plant, soil, or substance (or combina- tion thereof), that harbors disease-causing organisms and serves as a potential source of disease outbreaks. Resistance: See antibiotic resistance. Risk: Probability that an event will occur; a measure of the degree of loss ex- pected by the occurrence of a loss. RNA (ribonucleic acid): Any of various nucleic acids that contain ribose and uracil as structural components and are associated with the control of cellular chemical activities. Salmonella: A genus of bacteria that cause typhoid fever, food poisoning, and enteric fever from food poisoning. Salmonellosis: An infection by Salmonella bacteria. Most persons infected with Salmonella develop diarrhea, fever, and abdominal cramps 12 to 72 hours after infection. The illness usually lasts 4 to 7 days, and most persons recover without treatment. Severe acute respiratory syndrome (SARS): A contagious and sometimes fatal respiratory illness caused by a coronavirus, transmitted especially by contact with infectious material and characterized by fever, headache, body aches, dry cough, hypoxia, and usually pneumonia. SARS first appeared in China in November 2002. Southern Oscillation: A large-scale atmospheric and hydrospheric fluctuation centered in the equatorial Pacific Ocean; it exhibits a nearly annual pressure anomaly, alternatively high over the Indian Ocean and high over the South Pa- cific; the variation in pressure is accompanied by variations in wind strengths, ocean currents, sea surface temperatures, and precipitation in the surrounding areas.
408 GLOBAL CHANGE AND INFECTIOUS DISEASE DYNAMICS Species barrier: Difficulty or impossibility for an infectious agent to pass from one species to another (due to differences between species). Staphylococcus aureus: A facultatively anaerobic, gram-positive coccus that is the most common cause of staph infections. It is frequently part of the skin flora found in the nose and on skin. Surveillance: Used in this workshop summary to refer to data collection and record-keeping to track the emergence and spread of disease-causing organisms such as antibiotic-resistant bacteria. Syndrome: A group or recognizable pattern of symptoms or abnormalities that indicate a particular trait or disease (http://www.genome.gov/glossary. cfm?key=syndrome). Temporal barrier: A barrier that blocks the movement of the entire population of an organism some of the time. Transmission: Process by which a pathogen passes from a source of infection to a new host. Vaccine: A preparation of living, attenuated, or killed bacteria or viruses, frac- tions thereof, or synthesized or recombinant antigens identical or similar to those found in the disease-causing organisms, that is administered to raise immunity to a particular microorganism. Vector: An organism, such as an insect, that transmits a pathogen from one host to another. Vector-borne: Transmitted from one host to another by a vector. Vector-borne disease: (1) Mechanical: This includes simple mechanical carriage by a crawling or flying insect through soiling of its feet or proboscis or by passage of organisms through its gastrointestinal tract. This does not require multiplica- tion or development of the organism. (2) Biological: Propagation (multiplication), cyclic development, or a combination of these (cyclopropagative) is required before the arthropod can transmit the infective form of the agent to humans. An incubation period (extrinsic) is required following infection before the arthropod becomes infective. The infectious agent may be passed vertically to succeeding generations (transovarian transmission); transstadial transmission indicates its passage from one stage of the life cycle to another, as nymph to adult. Transmis- sion may be by injection of salivary gland fluid during biting, or by regurgitation or deposition on the skin of feces or other material capable of penetrating the bite
APPENDIX D 409 wound or an area of trauma from scratching or rubbing. This transmission is by an infected nonvertebrate host and not simple mechanical carriage by a vector or vehicle. However, an arthropod in either role is termed a vector. Virome: The sum of all viruses living in the tissues of the host or infecting organ- isms in the microbiome. Virulence: The ability of any infectious agent to produce disease. The virulence of a microorganism (such as a bacterium or virus) is a measure of the severity of the disease it is capable of causing. Virus: A small infectious agent that can only replicate inside the cells of another organism. Viruses are too small to be seen directly with a light microscope. Viruses infect all types of organisms, from animals and plants to bacteria and archaea. Weather: Condition of the atmosphere at a particular place and time measured in terms of wind, temperature, humidity, atmospheric pressure, cloudiness, and precipitation. In most places, weather can change from hour to hour, from day to day, and from season to season. Weather extremes (extreme weather events): Signifies individual weather events that are unusual in their occurrence (minimally, the event must lie in the upper or lower 10 percentile of the distribution) or have destructive potential, such as hurricanes and tornadoes. West Nile virus: A flavivirus that causes an illness marked by fever, headache, muscle ache, skin rash, and sometimes encephalitis or meningitis and that is spread especially from birds to humans by mosquitoes. Zoonotic infection: Infection that causes disease in human populations but can be perpetuated solely in nonhuman host animals (e.g., bubonic plague); may be enzootic.