1918 Spanish Flu pandemic - An unusually severe and deadly strain of avian influenza, a viral infectious disease, that killed some 25 million to 50 million people worldwide in 1918 and 1919. It is thought to have been one of the most deadly pandemics in human history. It was caused by the H1N1 type of flu virus. (The U.S. Public Broadcasting Service aired a 1998 documentary on the 1918 pandemic.)
Antibiotic - Medication used to treat infection caused by bacteria. Antibiotics do not protect against viruses (e.g., influenza). Examples of antibiotics are penicillin and streptomycin.
Antigen (an'ti-jen) - A substance, foreign to the body, that stimulates the immune system to produce specific antibodies (i.e., proteins that fight antigens). Antigens include foreign proteins, bacteria, viruses, pollen and other materials. The immune system considers the material to be "foreign" because it is not found naturally in the body.
Antiseptic - A substance that prevents the growth and reproduction of various microorganisms (such as bacteria, fungi, protozoa, and viruses) on the external surfaces of the body. Some are true germicides, capable of destroying the bacteria, while others merely prevent or inhibit their growth. Antibacterials have the same objective but only act against bacteria. Antibiotics perform a similar function, preventing the growth or reproduction of bacteria within the body. Disinfectants operate on nonliving objects such as medical instruments.
Antiviral - A type of drug that kills or weakens a virus or interferes with the ability of a virus to replicate in the human body. As with antibiotics for bacteria, specific antivirals are used for specific viruses.
ARDS - Acute Respiratory Distress Syndrome; a serious reaction to various forms of injuries to the lung, leading to impaired gas exchange and inflammation. Patients with ARDS experience severe shortness of breath and often require mechanical ventilation (life support) because of respiratory failure.
Asymptomatic - Having a disease, but showing no outward signs or symptoms of the disease.
Avian flu - Influenza viruses that infect birds are called avian influenza viruses (bird flu). These viruses occur naturally among birds worldwide. Wild birds usually do not get sick from them. However, avian flu is very contagious among birds and can make some domesticated birds, including chickens, ducks, and turkeys, very sick and kill them.
Only influenza A viruses infect birds, and all known subtypes of influenza A viruses can be found in birds. Usually, "avian influenza virus" refers to influenza A viruses found chiefly in birds, but infections with these viruses can occur in humans.
See also: H5N1.
Bacteria - Any of a large group of single-celled organisms that live in soil, water, plants, organic matter, or the live bodies of animals or people. Bacteria may be helpful, but in certain conditions may cause illnesses in animals and humans such as strep throat, most ear infections, and bacterial pneumonia. Bacteria are the most abundant of all organisms. They reproduce by simple cell division. Antibiotics kill bacteria.
Bacterial - Relating to or caused by bacteria.
Bird flu - See "Avian flu."
Business continuity plan - A comprehensive written plan to maintain or resume business in the event of a disruption. The term encompasses both disaster recovery planning and business resumption planning. The plan identifies procedures for sustaining essential business operations while recovering from a significant disruption.
CDC - The Centers for Disease Control and Prevention, one of the 13 major operating components of the United States Department of Health and Human Services (HHS). Its goal is to prevent and control infectious and chronic diseases, injuries, workplace hazards, disabilities, and environmental health threats.
Contagious - Infectious; easily diffused or spread, as from one person to another.
Contagion - Contagious disease; any disease easily transmitted by contact.
Contingency plan - A plan of action prepared in anticipation of a possible incident. See also: Business continuity plan.
Cytokine storm - When an immune system overreacts and damages the body, causing failure of multiple organ systems. Cytokine storms can happen rapidly and patients who suffer them have high mortality. Influenza is thought to be one of the rare conditions able to cause a cytokine storm.
Disinfect - To destroy disease-causing microorganisms by physical or chemical means.
Disinfectant - A chemical substance used to destroy viruses and microbes (germs), such as bacteria and fungi.
Disinformation - False or misleading information that is spread deliberately - sometimes maliciously, sometimes with good intentions. Disinformation can be repeated unwittingly by people who think the information is genuine and true. In contrast, when false or misleading information is spread unintentionally, it is properly termed misinformation. Misinformation is the result of ignorance.
Endemic - When a disease is more or less constantly present in the animal or human population of a particular locality.
Epidemic - A widespread outbreak of an infectious disease affecting many individuals in a community or a population at the same time. Compare to "pandemic."
Epidemiology - A branch of medical science that deals with the incidence, distribution, and control of disease in a population.
Flu - The shortened, common name for "influenza."
Germ - An informal term for a disease-causing microorganism (bacteria or virus).
H2H - Human-to-Human. When discussing contagious disease, it refers to the ability of the bacteria or virus to pass from one person to another (person-to-person).
H5N1 - Influenza A H5N1 virus – also called "H5N1 virus" – is an influenza A virus subtype that occurs mainly in birds, is highly contagious among birds, and can be deadly to them. Human cases of H5N1 infection have been reported in parts of Asia since December 2003. Of the few avian influenza viruses that have crossed the species barrier to infect humans, H5N1 has caused the largest number of detected cases of severe disease and death in humans. In the current outbreaks in Asia and Europe, more than half of those infected with the virus have died.
So far, the spread of H5N1 virus from person to person has been rare and has not continued beyond one person. Nonetheless, because all influenza viruses have the ability to change, scientists are concerned that H5N1 virus one day could be able to spread easily from one person to another. Because these viruses do not commonly infect humans, there is little or no immune protection against them in the human population. If H5N1 virus were to become able to spread easily from person to person, an influenza pandemic (worldwide outbreak of disease) could begin.
See also: Avian flu.
HHS - The United States Department of Health and Human Services. [Or visit the official HHS Web site for pandemic flu and avian influenza.]
Immunization - The process of rendering a person protected (immune) against a certain disease. Vaccination is a way to produce immunization. The vaccine stimulates the immune system to produce antibodies to ward off a particular infection (flu, measles, typhoid, etc.). However, just because a person has been vaccinated (received a vaccine) does not necessarily mean the person is immune. If the body did not correctly react to the vaccine or if the vaccine was defective, immunity would not occur. No vaccine produces immunity in 100% of the population to which it is given. Therefore, "vaccination" is not the same as "immunization."
Infectious - Capable of causing infection or spreading disease. Also known as "communicable" or "transmissible." Importantly, a person can be infectious without himself showing signs of the disease. (Someone carrying a bacteria or virus which can infect other people is said to be a "carrier" of the bacteria or virus.)
Influenza - A contagious disease caused by one of three strains of influenza virus (A, B, or C). It is an acute viral infection involving the respiratory tract in humans (nose, throat, and lungs). Commonly called the "flu," it is characterized by headaches, muscle aches, fever, weakness, and cough.
Isolation - The separation or restriction of activities of a person or animal who has a communicable disease (or is suspected of having the disease) and is presumed able to spread the disease. See also: Quarantine.
Microbe - A general term for a microorganism, such as bacteria, viruses, fungi, microscopic algae, and protozoa.
Misinformation - False or misleading information that is spread unintentionally. Misinformation is the result of ignorance. (Contrast with disinformation which is deliberately spread.)
Morbidity (rate) - A measure of the new cases of a disease in a population; the number of people who have a disease. "Morbidity rate" refers to rate of illness - the percentage of a population which contracts the disease. It is usually expressed as a number of people afflicted per 1,000, 10,000, or 100,000 people.
Mortality (rate) - The quality of being mortal or alive, thus subject to dying. "Mortality rate" is the ratio of the total number of deaths to the total population. It is usually expressed per 1,000 people. It is distinct from morbidity rate, which refers to the percentage of people in a population who have a disease.
Pandemic - An epidemic occurring over a very wide area, crossing international boundaries and usually affecting a large number of people. A global epidemic. Influenza (the flu) can be pandemic, since it has the ability to rapidly spread around the entire world. Compare to "epidemic."
Pathogen / pathogenic - Anything capable of causing disease. Usually refers to an organism that causes disease in another organism. But it can also refer to substances, like asbestos. Pathogenic microorganisms include viruses, bacteria, and fungi.
Quarantine - The separation or restriction of activities of well persons who are not ill but who are believed to have been exposed to a communicable disease and are therefore at high risk of becoming infected. See also: Isolation.
Replicate - To make a copy or duplicate of something. A flu virus must enter a cell in a host organism in order to make replicas or exact copies of itself. The copies, in turn, infect other cells.
Sanitize / sanitizer - To make sanitary or healthy (as by cleaning or sterilizing). Treat in such a way as to decrease the numbers of pathogens (organisms capable of causing disease) to levels at which they pose no danger of causing disease.
SARS - Severe Acute Respiratory Syndrome. SARS is a new respiratory illness. It is thought to be caused by a virus from a family of viruses called coronaviruses. These viruses are a common cause of upper respiratory illnesses in humans – including the cause of the common cold – and cause a number of diseases in animals. First reported in China in November 2002, SARS is contagious and sometimes fatal. Symptoms resemble pneumonia or influenza and include fever, headaches, body aches and dry coughing.
Social distancing - Increasing the distance or separation between people in everyday activities as a means of reducing the spread of contagious disease. Viewed differently, it involves discouraging or forbidding the social closeness of people. Examples: closing schools; having employees work from home; cancelling public gatherings (e.g., sporting events).
Surge capacity - The ability to respond rapidly to a sudden and dramatic increase in demand. Applied specifically to a health care system, it is the ability to rapidly expand beyond normal services to meet the increased demand for qualified personnel, equipment, medicines, and other elements of medical care in the event of a large-scale public health emergency or disaster.
Surveillance - The systematic collection, analysis, interpretation, and dissemination of health data to assist in the planning, implementation, and evaluation of public health interventions and programs.
Symptom - An indication that a person has a condition or disease. Some examples of symptoms are headache, fever, fatigue, nausea, pain, and rashes.
Tamiflu - An antiviral drug - a drug that fights viruses. In particular, Tamiflu fights influenza ("flu") viruses. When a person gets the flu, Tamiflu can make the sickness last a shorter time and be less severe. It doesn't cure the flu; there is no cure for the flu. Tamiflu is not a vaccine or an antibiotic.
Tamiflu inhibits the work of neuraminidase, a protein on the flu virus which lets viruses move from one cell to another. (Thus, Tamiflu is called a "neuraminidase inhibitor.")
In the absence of a vaccine for a new strain of flu, antivirals such as Tamiflu and Relenza are considered the best available pharmaceutical tools. [More information.]
"Tamiflu" is a brand name for oseltamivir phosphate.
Telecommuting - Using telecommunications technology to work from some location other than the regular business office. Often, the remote location is the employee's home, a field office, a hotel room, or a mobile setting. The employee's remote computer accesses the office network over telephone or Internet connections. Also, the employee communicates with co-workers, customers, and other business contacts through telephone, email, fax, teleconferencing, and Web conferencing. The rationale for telecommuting is, "Work is something you do, not something you travel to." Also known as teleworking.
In a flu pandemic, telecommuting would enable more "social distancing" which might reduce the spread of disease.
Transmit - To send or convey from one person or place to another. In medicine, transmission is the passing of a infectious disease from one individual or group to an uninfected individual or group.
Vaccine / vaccination - A preparation of weakened microorganisms given to create or increase resistance to a certain disease. The preparation contains killed microorganisms, living attenuated (weakened) microorganisms, or living fully virulent microorganisms, such as bacteria or viruses. The vaccine stimulates the immune system to produce antibodies to protect against a specific disease caused by the microorganism.
Vaccines are administered through needle injections, by mouth, and by aerosol. The process of administering vaccines is referred to as vaccination.
Viral - Having to do with a virus.
Virus - Any of a large group of microorganisms that causes various important diseases in humans, lower animals, or plants. In humans, these diseases range from the common cold and the flu to smallpox and hepatitis. Viruses are capable of growth and reproduction (replication) only in living cells. They insert their genetic material into a "host" cell and transform it into a "factory" for making viruses. Sooner or later, this kills the infected cell - causing disease.
The immune system usually can disable and kill viruses. However, a special set of viruses, called RNA viruses, can outmanuever the human immune system. They do this by mutating rapidly, often evolving faster than the immune system can develop an effective response to them.
Viruses usually infect only specific types of cells (frequently in just a single species) - like human lung cells (pneumonia) or human liver cells (hepatitis). Therefore, different kinds of viruses cause different kinds of disease.
Virulence / virulent - The power of a bacterium or virus to cause disease. Virulence can be measured by how many people the microorganism infects, how quickly it spreads through the body, the severity of the disease produced, and how many people die from it.
WHO - World Health Organization, the United Nations' specialized agency for health.