Ch.13 Infection and Disease
18. The stage of an infectious disease when specific signs and symptoms are seen and the pathogen is at peak activity is:
A) prodromal stage B) convalescent stage C) incubation period D) period of invasion* E) all of the choices are correct
19. The time from when pathogen first enters the body and begins to multiply, until symptoms first appear is the:
A) prodromal stage B) convalescent stage C) incubation period* D) period of invasion E) all of the choices are correct
20. The initial, brief period of early, general symptoms such as fatigue and muscle aches, is the:
A) prodromal stage* B) convalescent stage C) incubation period D) period of invasion E) all of the choices are correct
15. Exotoxins are:
A) proteins* B) only released after a cell is damaged or lysed C) antiphagocytic factors D) secretions that always target nervous tissue E) lipopolysaccharides
21. Which is mismatched:
A) secondary infection - infection spreads to several tissue sites* B) mixed infection - several agents established at infection site C) acute infection - rapid onset of severe, short-lived symptoms D) local infection - pathogen remains at or near entry site E) toxemia - pathogen's toxins carried by the blood to target tissues
11. The body site with resident flora that produces beneficial body products, including vitamin K and several other vitamins is the:
A) skin B) mouth C) large intestine* D) vagina E) nasal passages
6. Resident flora are found in/on the:
A) skin B) mouth C) nasal passages D) large intestine E) all of the choices are correct*
23. The objective, measurable evidence of disease evaluated by an observer is termed:
A) syndrome B) symptom C) sign* D) pathology E) inflammation
22. The subjective evidence of disease sensed by the patient is termed:
A) syndrome B) symptom* C) sign D) pathology E) inflammation
24. Local edema, swollen lymph nodes, fever, soreness, and abscesses are indications of:
A) toxemia B) inflammation* C) sequelae D) a syndrome E) latency
16. Enterotoxins are:
A) virulence factors B) toxins that target the intestines* C) proteins D) exotoxins E) all of the choices are correct
50. A _____ is an infection indigenous to animals that can, on occasion, be transmitted to humans.
Vector
Reservoirs of infection
Any person, animal, plant, soil or substance in which an infectious agent normally lives and multiplies. The reservoir typically harbors the infectious agent without injury to itself and serves as a source from which other individuals can be infected. The infectious agent primarily depends on the reservoir for its survival. It is from the reservoir that the infectious substance is transmitted to a human or another susceptible host.
List the Portals of exit
Respiratory, saliva Skin scales Fecal exit Urogenital tract Removal of blood
Patterns of infection - Secondary infection
another infection at another site by a different microbe
What is a Disease?
any deviation from health, disruption of a tissue or organ caused by microbes or their products
True pathogens
capable of causing disease in healthy persons with normal immune defenses Influenza - virus, plague - bacillus, malarial - protozoan
Opportunistic pathogens
cause disease when the host's defenses are compromised or when they grow in part of the body that is not natural to them Pseudomonas sp & Candida albicans
The "Hong Kong Flu
caused about 34,000 deaths in the United States
The Asian Flu
caused about 70,000 deaths in the United States
Endemic
disease that exhibits a relatively steady frequency over a long period of time in a particular geographic locale
List Mechanisms of adhesion
fimbrae flagella adhesive slimes or capsules cilia suckers hooks barbs
Virulence factors -antiphagocytic factors
help them to kill or avoid phagocytes, include leukocidins and capsules
Patterns of infection - systemic infection
infection spreads to several sites and tissue fluids (usually in the bloodstream)
Patterns of infection - Primary infection
initial infection, first microbe
Sepsis
is a potentially serious medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues. Severe sepsis is the systemic inflammatory response, plus infection, plus the presence of organ dysfunction.
Septicemia
is a related medical term referring to the presence of pathogenic organisms in the bloodstream, leading to sepsis, infection in a system or two.
Bacteremia
is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is considered abnormal
Etiology
is the study of causation, or origin. The word is derived from the Greek αἰτιολογία, aitiologia, "giving a reason for", it can be the genetic reason for the disease
Sequelae
long-term or permanent damage to tissues or organs, a pathological condition resulting from a disease, injury, or other trauma, a secondary consequence or result Latin sequēla - something that follows; a continuation Examples. Streptococcus pyogenes, Strep throat, can lead to rheumatic fever, and kidney damage or Chronic kidney disease, for example, is sometimes a sequela of diabetes
Incidence
measures the number of new cases over a certain time period, as compared with the general healthy population Down's Syndrome - 340,000 per year, 28,333 per month, 6,538 per week, 931 per day, 38 per hour, 0 per minute, 0 per second
Patterns of infection - localized infection
microbes enters the body & remains confined to a specific tissue
Morbidity rate
number of people afflicted with a certain disease per 1000, an inexact term that can mean either the incidence rate or the prevalence rate.
Sign
objective evidence of disease as noted by an observer, factual, should be recorded ex. White blood cell count, temperature
The Black Death
the bubonic plague returned to Europe, Starting in Asia, the disease reached the Mediterranean and western Europe in 1348 (possibly from Italian merchants fleeing fighting in the Crimea) killed twenty million Europeans in six years, a quarter of the total population and up to a half in the worst-affected urban areas
Cholera
the first pandemic 1816-1826, previously restricted to the Indian subcontinent, the pandemic began in Bengal, then spread across India by 1820. It extended as far as China and the Caspian Sea before receding. The third pandemic (1852-1860) mainly affected Russia over a million deaths
Mortality rate
the total number of deaths in a population due to a certain disease
Prevalence
total number of existing cases with respect to the entire population usually represented by a percentage of the population USA - 861,533 with diabetes 293,655,405 total population = 2.9% Canada - 95,372 with diabetes , 32,507,874 total population = .29%
Sporadic
when occasional cases are reported at irregular intervals
Epidemic
when prevalence of a disease is increasing beyond what is expected
Patterns of infection - focal infection
when the infectious agent breaks loose from a local infection and is carried to other tissues
What is True pathogens
-capable of causing disease in healthy persons with normal immune defenses -Influenza - virus, plague - bacillus, malarial - protozoan
Virulence factors - Toxigenicity
-capacity to produce toxins at the site of multiplication
What is an Opportunistic pathogens
-cause disease when the host's defenses are compromised or when they grow in part of the body that is not natural to them -Pseudomonas sp & Candida albicans
Patterns of transmission -Indirect contact -
-contact achieved through some intervening medium implicated in the spread of infection -Vehicle - fomites (inanimate material), food, water, biological products Airborne -droplet nuclei - the dried residue formed by evaporation of droplets coughed or sneezed into the air -Aerosols - is a suspension of airborne particles that contain living organisms or were released from living organisms
Patterns of transmission - Direct contact
-contact between mucous membranes &/or skin, portal of exit meets a portal of entry -Kissing, nursing, animal bites
Virulence factors - what is exoenzymes
-digest epithelial tissues & permit invasion of pathogens -Mucinase (amoebic dysentery), keratinase (ringworm), Collagenase (gangrene), hyaluronidase (staph, strepto)
what is Infectious dose (ID)
-minimum number of microbes required for infection to proceed -microbes with small Infectious Dose have greater virulence -1 rickettsial cell in Q fever -10 bacteria in TB, giardiasis -109 bacteria in cholera (1,000,000,000) -Lack of ID will not result in infection
Virulence factors - endotoxins
-secreted by gram-negative bacteria during lysis of the cell wall
Antonine Plague
165-180 BC. Possibly smallpox brought back from the Near East; killed a quarter of those infected and up to five million in all. 5,000 people a day were said to be dying in Rome
Pandemic
(from Greek παν pan all + δήμος demos people) epidemic across continents
What is Resident Flora?
*includes bacteria, fungi, protozoans, viruses and arthropods (see word document) *most areas of the body in contact with the outside environment harbor resident microbes; large intestine has the highest numbers of bacteria *internal organs, tissues & fluids are microbe-free *bacterial flora benefit host by preventing overgrowth of harmful microbes
Surveillance
- collecting, analyzing, & reporting data on rates of occurrence, mortality, morbidity, and transmission of infections
Patterns of infection - Focal infection
- is an infection at 2 different sites by one organism.
Virulence factors - exotoxins
- secreted by gram-positive and gram-negative bacteria, the cell wall stays intact (does not have to be lysed
List all Portal of Entries
- skin - gastrointestinal tract - respiratory tract - urogenital tract
Patterns of infection - Mixed infection
several microbes grow simultaneously at the same infectious site
Nonliving reservoirs
soil, water, air bacteria, fungi, helminths, protozoa (in all forms - spores, cysts, larvae)
Symptom
subjective evidence of disease as sensed by the patient ex. vomiting
Influenza
the "first" pandemic of 1510 traveled from Africa and spread across Europe, it is estimated that it killed about ten people in a thousand per day, or about 1%
30. Someone who inconspicuously harbors a pathogen and spreads it to others is a:
A) fomite B) carrier* C) vector D) reservoir E) source
Nosocomial infections
Diseases that are acquired during a hospital stay
37. Animals that participate in the life cycles of pathogens and transmit pathogens from host to host are:
A) fomites B) aerosols C) mechanical vectors D) droplet nuclei E) biological vectors*
36. The dried residues of fine droplets from mucus or saliva that harbor and transmit pathogen are:
A) fomites B) aerosols C) mechanical vectors D) droplet nuclei* E) biological vectors
13. STORCH is an acronym that represents the most common:
A) genera of resident flora B) sexually transmitted diseases C) portals of entry D) vectors E) infections of the fetus and neonate*
34. Reservoirs include:
A) humans B) animals C) soil D) water E) all of the choices are correct*
4. Endogenous infectious agents arise from microbes that are:
A) in food B) the patient's own normal flora* C) on fomites D) in the air E) transmitted form one person to another
27. The number of new cases of a disease in a population over a specific period of time compared with the healthy population is the:
A) mortality rate B) morbidity rate C) incidence rate* D) prevalence rate E) epidemic rate
3. Which is not terminology used for resident flora:
A) pathogenic flora* B) normal flora C) indigenous flora D) normal microflora E) all of the choices are correct
25. The study of the frequency and distribution of a disease in a defined population is:
A) pathology B) clinical microbiology C) medicine D) immunology E) epidemiology*
Peloponnesian War
430 BC, Typhoid fever killed a quarter of the Athenian troops and a quarter of the population over four years.
39. When would Koch's Postulates be utilized:
A) determination of the cause of a patient's illness in a hospital microbiology lab B) development of a new antibiotic in a pharmaceutical lab C) determination of the cause of a new disease in a microbiology research lab* D) formulation of a vaccine against a new pathogen in a genetic engineering lab E) whenever the scientific method is used to investigate a microbiological problem
35. A laboratory technologist splashed a blood specimen onto his face, eyes, nose, and mouth. This specimen was from an HIV positive patient. If this blood exposure leads to HIV infection in the technologist, the transmission route is:
A) direct B) fomite C) vehicle+ D) droplet nuclei E) aerosols
28. A disease that has a steady frequency over time in a population is:
A) epidemic B) endemic* C) pandemic D) sporadic E) chronic
Describe a Pandemic
A pandemic is a global disease outbreak. A flu pandemic occurs when a new influenza virus emerges for which people have little or no immunity, and for which there is no vaccine. The disease spreads easily person-to person, causes serious illness, and can sweep across the country and around the world in very short time.
17. Which is mismatched?
A) fimbriae - adherence to substrate B) capsules - antiphagocytic factor C) coagulase - dissolve fibrin clots* D) leukocidins - damage white blood cells E) hemolysins - damage red blood cells
32. An inanimate object that harbors and transmits a pathogen is a:
A) fomite B) carrier C) vector D) reservoir E) source
33. The intermediary object or individual from which the infectious agent is actually acquired is termed the:
A) fomite B) carrier C) vector D) reservoir E) source*
29. The primary, natural habitat of a pathogen where it continues to exist is called the:
A) fomite B) carrier C) vector D) reservoir* E) source
26. The principal government agency responsible for tracking infectious diseases in the United States is:
A) Centers for Disease Control and Prevention* B) World Health Organization C) National Institutes of Health D) United States Department of Agriculture E) Infection Control Committee
7. All of the following genera are considered resident flora of skin sites except:
A) Escherichia* B) Staphylococcus C) Corynebacterium D) Micrococcus E) Mycobacterium
10. Which genus is the most common resident flora of mouth surfaces?
A) Lactobacillus B) Streptococcus* C) Haemophilus D) Escherichia E) Mycobacterium
9. Which genus is resident flora of the mouth, large intestine, and, from puberty to menopause, the vagina?
A) Lactobacillus* B) Streptococcus C) Haemophilus D) Escherichia E) Mycobacterium
8. Resident flora of the intestines include the following:
A) Streptococcus B) Bacteroides C) Staphylococcus D) Haemophilus E) all of the choices are correct*
40. Most of the skin's resident flora are found in the uppermost, superficial layers of the epidermis.
A) True
41. Under certain circumstances, a person's resident flora can be opportunistic pathogens.
A) True
42. The virulence factors of a pathogen are established by how strong or weak a patient's body defenses are at the time of infection.
A) True
43. The Centers for Disease Control and Prevention assigns the most virulent microbes known to cause human disease to biosafety level 4.
A) True
44. A fetus can get an infection when a pathogen in the mother's blood is capable of crossing the placenta to the fetal circulation and tissues.
A) True
46. Septicemia means that a pathogen is present and multiplying in the blood.
A) True
48. Fomites, food, and air serve as indirect transmission routes of pathogens.
A) True
47. Sentinel animals are monitored for specific diseases in order to determine the potential for human exposure to a disease.
A) True B) False
14. Microbial hyaluronidase, coagulase, and streptokinase are examples of:
A) adhesive factors B) exotoxins C) hemolysins D) antiphagocytic factors E) exoenzymes*
2. All infectious diseases:
A) are contagious B) only occur in humans C) are caused by microorganisms or their products* D) are caused by vectors E) involve viruses as the pathogen
38. Nosocomial infections involve all the following except:
A) are only transmitted by medical personnel B) often involve the patient's urinary tract and surgical incisions C) the patient's resident flora can be the infectious agent D) Escherichia coli and staphylococci are common infectious agents E) medical and surgical asepsis help lower their occurrence*
5. The human body typically begins to be colonized by its normal flora:
A) before birth, in utero B) during, and immediately after birth* C) when a child first goes to school D) when an infant gets its first infectious disease E) during puberty
12. Virulence factors include all the following except:
A) capsules B) ribosomes* C) exoenzymes D) endotoxin E) exotoxin
1. Infection occurs when:
A) contaminants are present on the skin B) a person swallows microbes in/on food C) a person inhales microbes in the air D) pathogens enter and multiply in body tissues* E) all of the choices are correct
31. An animal, such as an arthropod, that transmits a pathogen from one host to another is a:
A) fomite B) carrier C) vector* D) reservoir E) source
Living reservoirs may or may not have symptoms
Asymptomatic carriers - gonorrhea, genital warts Passive carriers - health care professionals Vectors - live animals that transmits infectious disease, ticks, fleas, mosquitoes, flies, cockroaches, birds, rats
45. When an infected person is in the incubation period, that person cannot transmit the pathogen to others.
B) False
52. A _____ is the presence of small numbers of bacteria in the blood.
Bacteremia or Viremia
54. _____ are various bacterial enzymes that dissolve fibrin clots.
Bacterial kinases (Ex.Streptokinase, Staphylokinase)
51. _____ carriers are shedding and transmitting pathogen while they are recovering from an infectious disease.
Convalescent
49. Leukopenia is the _____ in the level of white blood cells in a patient.
Decrease
53. _____ are toxins that are the lipopolysaccharide of the outer membrane of gram negative cell walls.
Endotoxin
The "Spanish flu" - 1918-1919
In six months, 25 million were dead; some estimates put the total of those killed worldwide at over twice that number, An estimated 17 million died in India, 500,000 in the United States and 200,000 in the UK.
56. _____ are a set of criteria used to identify and link a specific microorganism as the etiologic agent of a new infectious disease.
Koch P.
55. The total number of deaths in a population due to a disease is the _____ rate.
Mortality
Epidemiology
The study of the frequency and distribution of disease & health-related factors in human populations, how often a disease presents itself and where it occurs
What is an Infection?
a condition in which pathogenic microbes penetrate host defenses, enter tissues & multiply
