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133 Cards in this Set
- Front
- Back
what is an infection and when does it occur?
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disease or condition caused by a microorganism
occurs when part of a microorganism's life cycle involves you |
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what is the process by which an infectious agent passes from one organism to another
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chain of infection
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what is an infectious agent capable of causing disease?
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pathogen
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what are the stages of infection?
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1. incubation period (no symptoms)
2. prodromal period 3. invasive phase 4. acme (peak) 5. decline phase 6. convalescent period 7. sequelae (remaining symptoms the body can't repair) |
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what is the widespread outbreak of a disease that affects many people?
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epidemic
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it is estimated that there are more types of ____ than all other creatures combined
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viruses
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what type of pathogen cannot reproduce on its own and replicate only inside another organism?
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virus
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what is a single-celled organism classified by shape, cell wall, and growth requirements?
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bacteria
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what is bacteria that live on/in a host at a particular location without causing harm and sometimes benefitting the host?
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normal flora
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what is the least understood infectious agent that is responsible for mad cow disease?
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prions
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which pathogen is said to be made entirely of protein, found in brain tissue, and alters other proteins?
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prions
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what causes a yeast infection?
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candida, which is a fungus
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what are organisms that live on/in a host and get food at the expense of the host?
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parasites: include helminths, protozoa, and ectoparasites
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what infectious agent are parasitic worms including roundworms, flukes, and tapeworms?
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helminths
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what infectious agent attaches to the human intestine and causes blood loss, and is the leading cause of anemia and malnutrition in developing countries?
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hookworm
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what infectious agent is the leading cause of disease and death in africa, asia, and central and south america which includes pneumonia and malaria?
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protozoa
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what infectious agent live on or in the skin and include fleas, ticks, lice, mosquitoes, and scabies?
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ectoparasites
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bacteria can double every ___ minutes
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20
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what is the first line of defense against infection?
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skin
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what are tiny, hairlike structures that rhythmically push foreign particles up and out, and where are they located?
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cilia, in the lungs
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what is an enzyme that breaks down bacteria and reduces the likelihood of infection?
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lysozyme
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what infectious agent causes chlamydia, gonnorrhea, meningitis, and tuberculosis?
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bacteria
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what is the complex set of cells, chemicals, and processes that protects the body against pathogens when they succeed in entering the body?
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immune system
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what 3 functions does the immune system perform?
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1. recognize foreign particles or infectious organisms
2. attack & destroy these agents 3. communicate with other parts of the immune system about when to begin and end an attack |
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what is the part of the immune system designed to rapidly dispose of pathogens in a non-specific manner?
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innate immune system
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what is an animal or insect that transmits a pathogen from a reservoir or an infected host to a new host?
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vector
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what is the speed and intensity with which a pathogen is likely to cause an infection?
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virulence
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what is the part of the immune system that recognizes specific targets?
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acquired immune system
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what is the series of cellular changes that bring blood to the site of an injury or infection?
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acute inflammatory response. part of the innate immune system
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what are the cells of the innate immune system?
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neutrophils, macrophages, and natural killer cells. neutrophils and macrophages are white blood cells that travel to the infection. natural killer cells are white blood cells that recognize and destroy virus infected cells or cells that have become cancerous
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what are "cell eaters" that digest damaged cells, foreign particles, and bacteria?
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phagocytes
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what are white blood cells that circulate in the bloodstream and lymphatic system, and what are they a part of?
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lymphocytes. part of the acquired immune system
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what is the network of vessels and organs throughout the body that serves to move fluid from body tissues and clear infection, and what organs does it include?
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lymphatic system. it includes the lymph nodes, spleen, and thymus
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what is the marker on the surface of a foreign substance that identifies it to immune cells as "nonself"?
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antigen
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what are the two main types of lymphocytes and what do they do?
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T cells: monitor events that may be occurring inside the body's cells. indicates infected cells as "nonself"
B cells: monitor the blood and tissue fluids. produce antibodies |
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explain helper T cells, killer T cells, and suppressor T cells
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helper T cells read the message of T cells and trigger the production of killer T cells and B cells. they also enhance the activity of the cells of the innate immune system and of B cells once they are activated
killer T cells attack and kill foreign cells and body cells that have been infected by a virus or have become cancerous suppressor T cells slow down and halt the immune response when the threat has been handled |
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what are proteins that bind to specific antigens and trigger events that destroy them? What are the events?
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antigens. they may neutralize the pathogen themselves because they are bound to the antigen, or signal other cells to destroy it, or activate parts of the innate immune system to destroy the pathogen
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what is reduced susceptibility to a disease based on the ability of the immune system to remember, recognize, and mount a rapid defense against a pathogen it has prevously encountered?
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immunity
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when was the concept of immunization first introduced and by whom? what disease made him figure it out?
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1796 by edward jenner
he realized that people infected with cowpox seldom became ill of smallpox |
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what are preparations of weakened or killed microorganisms or parts of the microorganisms that are administered to confer immunity to various diseases?
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vaccines. developed by jenner
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what are the benefits of breast feeding?
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benefits: reduced infections, allergies, and diarrhea. promote good health later in life. transferring antibodies from some diseases
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what is temporary immunity provided by antibodies from an external source - such as passed from mother to child in breast milk?
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passive immunity
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what are some uncontrollable risk factors of infectious diseases?
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age (young & old are most at risk), surgery, chronic diseases such as diabetes, being bedbound, genetic disposition, sociocultural factors, overcrowded living environments, and poverty (poor nutrition, stress, lack of health care)
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what are two types of malfunctions of immunity?
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autoimmune disease and allergies
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what are the causes of autoimmune diseases?
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- a part of the body is similar enough to an antigen on a foreign agent that the immune system mistakenly identifies it as "nonself"
- the immune control system fails to turn off an immune response once an infection is over these cause self-destruction, causing damage to body cells and tissues |
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what are some autoimmune diseases and who is more likely to have them?
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psoriasis, rheumatoid arthritis, multiple sclerosis, scleroderma, lupus erythematosis
more common in women than men |
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how do allergic reactions occur?
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when the immune process identifies a harmless foreign substance as an infectious agent and mounts a full-blown immune response
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what is the condition that is caused by inflammation of the bronchial tubes and spasm of the muscles around the airways in response to an allergen or other trigger?
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asthma
it is characterized by wheezing and shortness of breath |
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what is the hypersensitive reaction in which an antigen causes an immediate and severe reaction that can include itching, rash, swelling, shock, and respiratory distress? what drugs are used to treat it?
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anaphylactic shock
antihistamines for mild allergies, steroids to decrease an immune response, and epinephrine in emergency situations to reduce swelling |
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stress and the immune system
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long-term stress reduces the immune system, but short-term stress can actually enhance its functioning by activating the body's responses to stressors like puncture wounds, scrapes, and animal bites
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is it clear that stress causes illness?
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NO. more than 300 studies in the last 30 years have verified it, but it is still not 100% sure
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how often should you get a tetanus shot?
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every ten years should get a booster called diphtheria (Td) vaccine
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who are most susceptible to influenza?
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children age 6 months to 5 years, pregnant women, people aged 50 or older, and people with chronic health conditions
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how many americans have asthma? who are most at risk? is it genetic?
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20 million americans have it, 9 million are children. people with allergies are more at risk along with children. it does run in families
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infections from blood banks have (increased, decreased) in recent years
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decreased
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how many organisms are associated with food-related illnesses?
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250
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SARS
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severe acute respiratory syndrome
it is caused by a previously unknown carona virus and is spread by coughing, sneezing, skin contact, and through air. it has no vaccine or treatment, and incubation period is 2-10 days. air travel was a key reason for why it spread symptoms can progress rapidly to a severe form of pneumonia |
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what are some variables associated with the susceptibility to infection if exposed to an STD?
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- gender
- age at first intercourse - general health of the susceptible person - women are at greater risk because they have a larger mucosal surface of the vagina and cervix - young women because cervix is more susceptible to infection in the first few years of menstruation - abrasions |
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condoms and STDs
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not 100% effective at preventing STDs
there is no data if they reduce the risk of transferring HPV |
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what are the ABCDs of STD prevention?
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- abstinence
- be faithful - condoms - detection is critical. some STDs have no symptoms |
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all hepatitis viruses cause ______
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inflammation of the liver
symptoms include fatigue, weakness, loss of appetite, and jaundice |
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what percent of blood transfusion recipients before 1990 developed hepatitis?
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10%, mostly hepatitis C
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how many americans are infected with hepatitis C?
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4.1 million
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what is the incubation period of hepatitis C?
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4-6 weeks
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what percent of people infected with hepatitis C show symptoms?
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20%
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what percentage of people with hepatitis C will develop liver failure after 20 years?
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1/5
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what is scarring of the liver called?
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cirrhosis
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what is the leading reason for the need of liver transplants?
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hepatitis C
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what have community programs done to reduce the risk of hepatitis C?
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they have been linking drug users with treatment programs and encouraging safe injection programs for addicts until they can receive treatment
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how do people who have hepatitis C slow the progression?
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avoiding alcohol, limiting use of medications that affect the liver (such as acetaminophen), and getting vaccinated for hepatitis A and B
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what bacterial infection has been recently associated with tattooing?
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methicillin-resistant staphylococcus aureus (MRSA)
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what is a drug that works by killing or preventing the growth of bacteria?
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antibiotic
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when was penicillin discovered and by whom?
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1928 by alexander fleming
it is a common mold, and was the first antibiotic |
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what is the lessened sensitivity to the effects of an antibiotic?
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antibiotic resistance
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what 2 factors contribute to antibiotic resistance?
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1. the frequency with which resistant genes arise naturally among bacteria through mutation
2. the extent of antibiotic use |
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antibiotics are _____, so they kill ______ as well as pathogens and increase antibiotic resistance in _____ as well as in pathogens
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nonspecific; helpful bacteria; helpful bacteria
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antibiotics are estimated to be not needed in up to _____ percent of the cases in which they are prescribed
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50%
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what percent of antibiotics produced are used on livestock?
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70%
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what program, run by the CDC and FDA, collects and analyzes information on possible adverse events that occur after vaccinations?
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the vaccine adverse events reporting system
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what is the leading cause of infectious disease and death?
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pneumonia
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what disease is described as an infection of the lungs or lower respiratory tract?
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pneumonia
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who are most at risk for pneumonia?
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young children and older adults
risk factors also include environmental pollutants, tobacco use, alcohol use, drug use, and close living situations |
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is pneumonia viral or bacterial?
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can be both
viral is milder, but both can be deadly |
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what is the problem with treatment for pneumonia?
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up to 40% of the streptococcus bacterium that causes it is resistant to penicillin, and 96% of influenza A (causes pneumonia) is resistant to 2/4 of the antiviral drugs
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who is most at risk for diarrhea?
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children. it kills 2-3 million children each year
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what can diarrhea lead to and what causes it? how can it be prevented?
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can lead to dehydration, electrolyte imbalances, malnutrition, and growth delay
caused by viruses and bacteria 25% of diarrhea deaths are caused by the rotavirus spread through contaminated food and water, so sanitation and clean water reduce the risk |
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what is the most common infectious disease worldwide? what percent of the population is infected?
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tuberculosis; 30%
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what kind of infection is not currently active but could reactivate at a later time?
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latent infection
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describe tuberculosis
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it is caused by a mycobacterium, a subset of bacteria
it is a latent infection, and only 5-10% of infected people develop the active disease symptoms of active tuberculosis include cough, fatigue, weight loss, night sweats, fever, and coughing up blood |
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tuberculosis is the leading cause of death among what kind of people?
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people infected with HIV
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is there a treatment for tuberculosis?
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yes. a combination of 3-4 anti-TB drugs taken for 6-9 months. some types of TB are resistant which has caused a large public health concern
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describe malaria, including who's at risk, where it is common, symptoms, and treatment
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it is a mosquito-borne disease caused by four species of the plasmodium parasite
deaths occur mostly among young children most deaths occur in sub-saharan africa symptoms include high fever, chills, sweats, headache, nausea, comiting, and body aches. symptoms develop 7-30 days after being bit severe malaria can lead to confusion, seizures, coma, heart failure, kidney failure, and death treatment varies depending on the type the anopheles mosquito is still present in many southern states and periodically causes small outbreaks of malaria |
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what is the name for the infection of the respiratory tract caused by the pertussis bacterium?
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whooping cough
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among students with a prolonged cough, about ____ percent have whooping cough
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30%
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how is influenza catagorized?
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influenza A and B cause the flu
influenza A is broken up into subtypes based on antigens on the surface of the virus, called H and N there are only three influenza A subtypes that affect humans (H1N1, H1N2, and H3N2) |
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avian flu
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H5N1
in asian countries among domesticated birds with some humans infected by the birds, not by other humans humans do not have immunity to it in some areas, 50% of people with avian flu have died vaccination would not be effective because it changes could lead to a pandemic |
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what is a viral disease characterized by fever, headache, and swollen salivary and parotid glands?
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mumps
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transmission and treatment of mumps
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transfered by respiratory secretions from an infected person
no treatment |
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what is a common bacterium carried on the skin or in the noses of healthy people and is one of the most common causes of skin infection?
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staphylococcus aureus (staph)
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what is the most common bacterial infection?
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urinary tract infection (UTI)
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UTI statistics
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more common in women
1/3 of women will have a UTI by age 24 more than 50% of women will have at least one UTI in their lifetime usually involve the lower urinary tract or bladder mostly caused by the bacteria E. coli |
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the primary pathogens responsible for STDs are ______ and _______
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viruses and bacteria
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HIV/AIDS statistics
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2.5 million new infections and 2.1 million deaths occured with 3/4 being sub-saharan africans
in sub-saharan africa, it is mostly heterosexual contact, with 61% infected being women 1.3 million are infected with HIV in north america sexual contact is involved in 85% of newly diagnosed HIV infections in the US, with over half being homosexual contact and 18% being intraveneous drug use |
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how did HIV start?
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from the simian immunodeficiency virus found in chimpanzees in africa
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what is the name for the level of the HIV virus that continues to circulate in the blood and body fluids and causes the person to be asymptomatic for 2-20 years?
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viral load set point
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what are infections that occur when the immune system is weakened and do not usually occur in a person with a healthy immune system? what are common diseases that have this?
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opportunistic infections
AIDS, pneumonocystis carinii pneumonia, kaposi's sarcoma, and tuberculosis |
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the time of highest circulating virus is at what time?
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shortly after initial infection
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what percent of people in the US do not know they are infected with HIV?
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25%
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what is the transmission of a disease from an infected mother to her child called?
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perinatal transmission
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what medications can be used to prevent a mother from transferring a disease to her baby?
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antiretroviral
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what percent of treated and untreated women infect their baby?
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untreated = 30%
treated = 2% |
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what percent of US citizens know their HIV status? what about sub-saharan africa?
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75% in US
12% of men and 10% of women in sub-saharan africa |
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what are complicated drug combinations used to overcome drug resistance in different strains of HIV?
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drug cocktails
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what is the name for a compound or chemical in the form of a cream, gel, or suppository that would kill microorganisms and that could be applied topically to the vagina or rectum before intercouse, reducing the risk of STD transmission?
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microbicide
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what percent of people age 18-26 have chlamydia?
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4.1%
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who has the highest rates of chlamydia?
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young women, particularly african american women
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what percent of men and women show no signs of chlamydia?
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women: 75%
men: 50% |
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name some bacterial STDs
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chlamydia, gonorrhea, pelvic inflammatory disease, syphilis, and bacterial vaginosis
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who has the highest rates of gonorrhea?
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young women
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what antibiotics treat gonorrhea?
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used to be fluoroquinolones, but now is cephalosporins
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what disease occurs when bacteria from the vagina or cervix spread upward into the uterus and fallopian tubes?
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pelvic inflammatory disease (PID)
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what disease is caused by infection from the bacterium treponema pallidum and is increasing in men having sex with men?
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syphilis
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what disease is caused by the normal vaginal flora (lactobacillis) being replaced with different bacteria, causing vaginal discharge and unpleasant odor?
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bacterial vaginosis
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what percent of the general population and what percent of men and women on college campuses have HPV?
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15% of general population
46% of women on college campuses over 50% in men who have sex with men |
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what are some viral STDs?
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HPV, herpes, hepatitis
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can you spread herpes when there isn't a visible lesion?
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yes
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can herpes be transmitted to a newborn during delivery? when is the greatest risk of infection?
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yes
greatest risk is when a woman is infected toward the end of her pregnancy. women with it should get a c-section |
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how is hepatitis A transmitted?
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through fecal-oral contact and through contaminated food or water
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how is hepatitis B transmitted?
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mostly sexually transmitted but can also be spread through infected blood
|
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which hepatitis causes chronic liver disease?
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hepatitis B
|
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what is commonly mistaken for as an STD and is caused by a protozoa? how is it treated?
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trichomoniasis ("trich")
treated with the antibiotic metronidazole |
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what percent of women have had an episode with candidiasis in their lifetime?
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75%
|
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which country has the highest rates of STDs?
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the US
we are 50-100 times higher than those of other industrialized countries |