Ch 14 Infection and Infectious Diseases
what are the three types of reservoirs?
-Animal Reservoir -Human Carriers -Nonliving Reserovir
Immune suppression is when_ (describe what it is and causes for it)
-Anything that suppress the body's immune system -immune system does not work properly -due to treatments (cancer treatment and medicines), malnutrition, genetics, chronic disease, emotional and physical stress, extremes of age (too old or too young)
Resident Microbiota (longevity in the body or duration within body/ effects on humans)
-Are a part of the normal microbiota throughout life -Causes no harm, may be helpful
If the womb is a free microbe environment, when does the baby obtain the microorganisms that will be part of the resident and transient microbiota?
-At birth, microorganisms come into contact with the baby's body, and the first breath and food introduce others. -Microbiota begins to develop during the birthing process -Much of ones resident microbiota established during the first months of life -First breath got microorganisms of upper respiratory tract -Colonize skin (contact from others) -First meals colonize gut.
what are some examples of living microorganisms that infect humans? (3) what is the most common?
-Bacteria (Most common) -Fungi -Protozoan
How the numerous agencies at the local, state, national, and global. work with the entire spectrum of health care personnel to promote public health? (concerning sharing of data)
-By submitting reports on incidence and prevalence of diseases to public officials, physicians can subsequently learn of current disease trends -Public health agencies often provide physicians with laboratory and diagnostic assistance -State accumulates data similar to MMWR to assist local health departments and medical practitioners with diagnostic testing for diseases -Data collected by the state is reported CDC (branch of the US public health service) -CDC conduct research in disease etiology, prevention, immunization
what are the ways to control nosocomial infections?
-By using aggressive control measures -These include: -disinfection -medical aspesis (good housekeeping, handwashing, bathing, sanitary handling og food, proper hygiene, and precautionary measures to avoid to spread of pathogens among patients) -surgical asepsis -sterile procedures -Isolation of particularly contagious or susceptible patients -Establishment of a nosocomial infection control committee charged with surveillance of nosocomial diseases and review of control measures
Antiphagocytic factors prevent_
-Certain factors prevent phagocytosis by the host's phagocytic cells
why transient microbiota cannot remain in the body?
-Competition from other microorganisms -Elimination by the body's defenses cells (immune system) -Chemical or physical changes in the body (pH and temperature)
Beta hemolysis
-Complete hemolysis (takes blood cells and completely breaks them down) -Transform blood gar from red to normal agar color (complete clearing of the blood cells around a colony) -Look yellow halo around the bacteria if looked against light
Animal reservoirs (ways to get infected from them (3), definition and disease they cause, effects on animal reservoir)
-Direct contact with animal or its waste, Eating animals, Bloodsucking arthropods (vector) -Diseases that spread naturally from animals to humans are called zoonoses or zoonotic diseases -sometimes may affect the animal reservoir
Extracellular enzymes (what they dissolve, how they help the microorganism)
-Dissolve structural chemicals in the body -Help pathogen maintain infection, invade further, and avoid body defenses
Two categories of extracellular enzymes (include enzymes in each category)
-Dissolve structural chemicals in the body: hylauronidase and collagenase -Help pathogen maintain infection, invade further, and avoid body defenses: coagulase and kinase
How biofilms works in terms of attachment?
-Does not attach to host but attach to other bacteria in a web -form large complex of sticky mass that are harder to get right out of them using antibitotics
List the portals of exit (11)
-Ear (earwax) -Broken skin (blood) -Skin (flakes) -Anus (feces) -Eyes (tears) -Nose (secretions) -Mouth (saliva, sputum) -in females: mammary glands (milk secretions) and Vagina (secretions, blood) -Urethra (urine) -Seminal Vesicle (Semen and lubricating secretions)
Types of nosocomial infections (describe them) (3)
-Exogenous - pathogen acquired from the health care environment -Endogenous - pathogen arise from normal microbiota due to factors within the health care setting (opportunistic disease) -Iatrogenic - results from modern medical procedures (treatment such as with antibiotics or medical procedures such as surgery).
why pathogens need reservoirs?
-Most pathogens cannot survive long outside of their host -If pathogens are to enter new hosts, they must survive in some site from which they can infect new hosts.
what are the types of symbiosis?
-Mutualism -Commensalism -Parasitism
Gama hemolysis
-No hemolysis or no damage to the red blood cells -Blood agar remains the same
Describe the portal of entry: parental route (route, where, how get?)
-Normal routes circumvented. -Pathogen deposited directly to tissues beneath skin or mucous membrane. -Punctures, abrasions, stabs, etc,
superinfections
-Nosocomial Iatrogenic infection -result of animicrobial drugs that, by inhibiting some resident microbiota, allow other to thrive in the absecne of competition
where adhesins are found within bacteria?(3)
-On fimbriae, flagella, and glycocalyces
Alpha hemolysis
-Partial hemolysis or partial damage of red blood cells -Many organisms produce a green pigment when grown on blood media
what are the two ways that phagocytosis is blocked or avoided by bacteria?
-Phagocytosis blocked by capsule -Incomplete phagocytosis
Describe the portal of entry: placenta (think about its function and the percent of chance to contamination)
-Placenta provides nutrients to baby -Does serve as effective barrier, but some pathogens can cross and infect fetus or embryo. (2% of pregnancies)
Droplet transmission (definition, examples, range of contamination)
-pathogens can be transmitted via droplet nuclei (droplets of mucus) that exit the body during exhalation, sneezing, and coughing. -Pathogen must travel less than 1 meter to be considered droplet transmission
4 extracellular enzymes
Hyaluronidase Collagenase Coagulase Kinase -
How can you change a bacteria from being pathogenic to avirulent in regards with ligands?
Inability to make attachment proteins (virus) or adhesins (bacteria) renders the microorganisms avirulent
What are some exposures to microbes? (6)
Reach us by food, water, air, wounds, biting, sexual intercourse
portals of entry (definition)
The entry sites of pathogens into the human body
Explain why some of the resident bacteria are commensal?
They feed on excreted cellular wastes and dead cells without causing harm
Toxemia
Toxemia refers to toxins in the bloodstream that are carried beyond the site of infection
From where a disease can be transmitted? (2)
Transmission from either a reservoir or portal of exit
Ex of organism that is parasitic?
Tuberculosis bacteria in human lung
Symptoms
subjective characteristics of a disease that can be felt by the patient alone.
Microbes live with their hosts in _relationships
symbiotic
Pain, headache, dizziness, and fatigue would be a sign or symptom?
symptom
what organization coordinates efforts to improve public health throughout the world, particularly in poor countries ?
the World Health Organization (WHO)
disease is the consequence or the outcome of the infection?
the consequence but not the outcome
index case
the first case of the disease in a given area or population.
which of the portals of entry is not technically a portal of entry? why?
the parental route because it is not a portal of entry but instead a means by which the portals of entry can be circumvented
the mucous membranes line_ (the ones that are portals of entry) (5)
the respiratory tract gastrointestinal tract urinary tract reproductive tract conjunctiva covering the surface of the eye.
what are the uses of signs and symptoms? (include what else you need)
they are used in conjunction with laboratory tests to make diagnoses
pathogenicity
ability of a microorganism to cause disease
What are the categories to classify infectious diseases when grouped by time course (longevity) and severity? (4)
acute subacute chronic latent
subcategories of vehicle transmission
airborne waterborne foodborne
Antiphagocytic factors allow them to_
allow them to survive inside of macrophages.
a highly virulent organism _causes a disease
almost always
Morbidity
any change from a state of health
Why zoonoses are difficult to eradicate?
because extensive animal reservoirs are often involved and they would be more difficult depending on the larger the animal reservoir and the greater the contact between human and animals.
An animal that carries a pathogen and also serves as host for teh pathogen is a _vector
biological
what type of symbiosis does most normal microbiota's organisms have with humans?
commensalism
tell one case in which changes in relative abundance of normal microbiota may allow opportunity for a member to thrive and cause disease
consumption of antibiotics -use antibiotics disrupt the levels by killing microorganisms in your gut by trying to kill the bad ones that results in the killing of the good ones
Infectious disease categories depending on the origin of the infection
copmmunicable noncommunicable
epidemiology is the frequent study of diseases at_
different levels of the population
subcategories of contact transmission
direct indirect droplet
Chronic disease
disease develops slowly but is continual or recurrent.
Latent disease (definition and example)
diseases are those in which a pathogen remains inactive for a long period of time before producing signs and symptoms (become active). (hepatitis)
Subacute disease
diseases have durations and severities that lie somewhere between acute and chronic.
zoonoses
diseases that spread naturally from their usual animal host to humans
What is the most effective way to prevent nosocomial infections?
effective handwashing by all medical and support staff
extracellular enzymes enable them to_ (4)
enable them to dissolve structural chemicals in the body and thereby maintain an infection, invade further, and avoid body defenses
what are the four terms for the occurrence of disease when combining both geographic distribution and frequency?
endemic disease sporadic epidermic pandemic
Extracellular enzymes are_
enzymes secreted by the pathogen
the study of disease at the population level is done by_
epidermiology
The study of the cause of a disease is_
etiology
what are the symptoms of the presence of endotoxins? (5)
fever, inflammation, diarrhea, shock, and blood coagulation
what are examples of specialized structures for attachment? (2)
fimbriae (small hairs) and slime layer (glycocalyxes) loosely attaches
usually the host cell receptor would be a _
glycoprotein containing sugar molecules
Exotoxins (what type of gram bacteria produce them, the types, definition, what they cause)
gram +/- cytotoxin, neurotoxin or enterotoxin toxins that are secreted by pathogens into their environment (living pathogen) -Destroy host cells and interfere with host metabolism
Syndromes
group of symptoms and signs that collectively characterize a particular disease or condition.
adhesins of bacteria enables the organism to attach to the_
host cellular tissue or surface of cell
what is a type of capsule used as antiphagocytic factor?
hyaluronic acid capsules
noncommunicable
infectious diseases arise from outside of hosts or from normal microbiota.
the suffix "emia" means
inside the blood
Experimental epidemiology
involves testing a hypothesis resulting from analytical studies concerning the cause of a disease.
Acute disease
is one which develops rapidly but lasts only a short time, whether resolving or causing death of the host.
Descriptive epidemiology
is the careful recording of data concerning a disease
Descriptive epidemiology includes_
it often includes detection of the index case
how body limits the extent and duration of infections?
it produces phagocytic cells (white blood cells) that engulf and remove invading pathogens
An example of attachment protein for adhesion is_
ligands
Symbiosis
means "to live together."
subcategories of vector transmission
mechanical biological
Disease is also referred to as_
morbidity
how a bacteria that produces extracellular enzymes can become avirulent?
mutant strains of the same species that have defective genes for these extracellular enzymes
should you have a large number of people that got infected by a disease to be considered epidemic?
no because you just need to have more cases than historical statics indicate are expected
Other names for Normal Microbiota
normal flora and indigenous microbiota
Sign
objective manifestations of the disease that can be observed or measured by others
which, incidence or prevalence, is a cumulative number?
prevalence
contamination
refers to the mere presence of microbes in or on the body
what is the major way the immune system fight infections?
through phagocytosis
if toxins are present there would be a_damage
tissue
how epidemiology track occurrence of disease?
using two methods: incidence and prevalence
Infection
Successful invasion of the body by a pathogen
MMWR
- Morbidity and Mortality Weekly Report Publish weekly by CDC.
Coagulase (what does and what its function for the bacteria)
- coagulates blood proteins --enzyme that starts coagulation blood proteins (see clumps) -when the cloatting happens, the bacteria can grow inside the coagulate and helps it to avoid body immune system cells -Clot provides hiding place for bacteria
Kinase (what it does, how helps bacteria, and what allows)
- digests clots -helps bacteria get out of the protective clot to be able to infect after reproduce -Allow subsequent invasion of damaged tissue
Collagenase
- digests collagen
prevalence (definition and what type of disease)
- number of total cases of a disease in a given area during a given period of time -diseases that last a long time
endemic
-A disease that normally occurs continually at a relatively stable incidence within a given population or area -Will be find within the location where we expect to find those particular pathogens
when a patient is infectious in these steps of the disease?
-A patient is likely to be infectious during every stage of disease -Depends on the disease, if the microorganism is still inside of you, the chances infects you are small but still are there (all and any stages)
biofilm (definition, use, adheres to, example)
-A slimy community of microbes growing on a surface -Used to attach to others to form a sticky web of bacteria and polysaccharides -Adheres to a surface within the host -Ex: dental plaque
Ex of organism that is commensalistic?
staphylococcus on skin
Exotoxin vs endotoxin where they are made within the bacteria/ chemical nature/ toxicity/ effect on host/ fever producing?/ antigenicity (stimulate immune response)
-Exotoxins: metabolic product secreted from living cells/ protein or short peptide/ high/ Variable depending on source (cytotoxin, neurotoxin, enterotoxin)/ no/ strong (stimulates antitoxin production) -Endotoxins: portion of outer (cell wall) membrane released upon cell death/ lipid portion of lipopolysaccharide (lipid A) of outer (cell wall) membrane/ low, but fatal in high doses/ Fever, lethargy, malaise, shock, blood coagulation/ yes/ weak
Capsules (type, characteristics, 2 ways help for antiphagocytic factor of bacteria)
-Glycocalyx -tightly attach -hide from immune system -enable bacteria to avoid process of phagocytosis -*Often composed of chemicals found in the body and not recognized as foreign -*Can be slippery making it difficult for phagocytes to engulf the bacteria (pseudopodia cannot grip capsule)
Human carriers
-Humans may be asymptomatic carriers of infection. -Some carriers eventually develop the disease, while others remain a continued source of infection without ever becoming sick. -Presumably many such healthy carriers have defensive systems that protect them from illness. -somebody that harbor the microorganisms but they are asymptomatic (no symptoms/ signs/ manifestation) but can be the source of infection that other person get sick
hyaluronic acid (digested by and where can be found)
-Hylaruonidase -Glue that holds animal cells together -it is part of the extracellular matrix that holds cells together (glue cells together)
describe circumnstances that the opportunistic pathogens can cause a disease (3)
-Immune suppression -Changes in the normal microbiota - changes in relative abundance of normal microbiota may allow opportunity for a member to thrive and cause disease -Introduction of normal microbiota into unusual site in the body
who performed the earliest descriptive epidemiological study? (describe it)
-John Snow, who studied a cholera outbreak in London, and mapped the locations of the cholera cases in a particular part of the city -He found cases were clustered around the Broad Street water pump -The disease was spread via contamination of drinking water by sewage
Portals of exit (why use them and definition)
-Just as infections occur through portals of entry, so pathogens must leave infected patients through portals of exit in order to infect others. -Exit site of pathogenic microorganisms, which can be the same as the portal of entry or via secretions and excretions of the body
Describe the portal of entry: mucous membranes (where mucous membranes localized, what they provide to the microbe, what is the most commonly used site, entry is through the_,pathogens that enter stomach are able to do what and how they enter?)
-Line the body cavities that are open to the environment -Provides a moist, warm environment that is hospitable to pathogens -Respiratory tract is the most commonly used site of entry - entry to respiratory is through the nose, mouth or eyes -Pathogens able to survive the acidic pH of the stomach may use the gastrointestinal tract as a route of entry
what are the benefits that microbes have and humans have from having a mutualism relationship?
-Microbe have a warm and moist environment where to live and get nutrients -Human obtains vitamins and nutrients that are produced by the microbe
Microbial antagonism (other name and definition)
-Microbial competition -Normal condition in which established microbiota use up available nutrients and space, reducing the availability of arriving pathogens to colonize (also produce toxic wastes)
How health public agencies use information of epidemiology to limit disease transmission?
-Public health organizations use epidemiological data to promulgate rules and standards for clean, potable water; that is, water that is fit to drink. -They also work to regulate food safety standards -to prevent disease by controlling vectors and animal reservoirs -to educate people to make healthful choices concerning the prevention of disease. (flu/ handwashing/sexual attitudes to prevent sexual transmission of disease) -Immunization -Locate and prophylatically treat individuals exposed to contagious pathogens -Establish isolation and quarantine measures to control spread of pathogens
Normal Microbiota
-Refers to the organisms that colonize the body's surfaces without normally causing disease -Live in and on the body
Transitional Microbiota (Duration within the body, location where they are found in the broad sense, can remain in body or not?)
-Remain in the body for only hours to months before disappearing -Found in the same regions as resident microbiota -Cannot persist in the body
what are the two types of normal microbiota?
-Resident Microbiota -Transitional Microbiota
what are the potential outcomes of contamination?
-Resident microbiota, -transient microbiota -Infection - successful invasion of pathogen (May or may not cause disease.)
what is a factor that difficult the treatment of diseases? (talking about ways to treatment with medicine)
-Resistant and growing resistant to antibiotics-> difficult to treat them when they are acquired -Ways to become resistant: -new mutation -acquire piece of DNA from a resistant pathogen (conjugation, transformation, transduction).
What are the 4 portals of entry for microbes into the body?
-Skin -Mucous membranes -Placenta -Parental route
Describe the portal of entry: skin (2 ways microbes enter)
-Some pathogens can enter through openings (hair follicles and sweat glands) or cuts -Others enter by burrowing into or digesting the outer layers of skin
Antiphagocytic chemicals (2 ways aid in antiphagocytic factor of bacteria)
-Some prevent fusion of lysosome and phagocytic vesicles (ex: M protein) -Leukocidins directly destroy phagocytic white blood cells
fimbriae
-Sticky, proteinaceous extensions of some bacterial cells that function to adhere cells to one another and to environmental surfaces
epidemiology
-Study of the occurrence and spread of diseases within groups of humans -Study of where and when diseases occur and how they are transmitted within populations
Asymptomatic (other name and definition)
-Subclinical -Lack symptoms
ligands (definition and who uses them)
-Surface lipoproteins or glycoproteins that bind to complementary host cell receptors -bacteria and viruses use them
Mutualism (definition and how it varies)
-Symbiotic relation -in which both members benefit -Varies from being not necessary to being very important and that organisms cannot live without each other
Parasitism (definition and how varies)
-Symbiotic relation -a parasite benefits while the host is harmed -Slight damage to kill the host
Commensalism
-Symbiotic relation -one member benefits while the other is relatively unaffected.
Describe the womb in terms of colonization of microorganisms (normal microbiota)
-The womb is an axenic environment, free of microbes. -Development of the baby within the mother's womb is generally free of microorganisms -Due to amniotic membrane and fluid and the axenic environment
What are some parts that has resident microbiota? (also temporarily colonized by transient organisms) (6)
-Upper respiratory tract -Upper and Lower digestive tract -Female urinary and reproductive system -Male urinary and reproductive system -Eyes -Skin
avirulent (definition and reasons)
-does not cause disease -harmless -genetic change or mutation and exposure to certain physical or chemical agents (vaccines)
what are examples of free microbe (axenic) environment?
-Womb -Blood -Cerebral Spinal Fluid
what parts of the body normally will become parts of normal microbiota?
-any that has opening to outside (skin, digestive, respiratory, etc) -Anything that is in contact with the outside environment
Vector (definition and types)
-are animals such as arthropods that transmit diseases from one host to another. -can be either biological or mechanical
Adhesion (other name and definition)
-attachment -Process by which microorganisms attach themselves to cells
How health care workers stimulates the production of antitoxins?
-by administering immunizations composed of toxoids, which are toxins that have been treated with heat and chemicals to make them nontoxic but still capable of stimulating the production of antibodies
Body fluid transmission (definition and who has to be specially careful about it, how obtained)
-can occur when blood, urine, and other fluids are handled outside the body. -health care workers need to be careful -from contacting conjuctiva or any breaks in the skin or mucous membranes
what are the two structures or virulence factors that help for antiphagocytic functions?
-capsules -Antiphagocytic chemicals
Virulence factors
-characteristics that contribute to an organisms virulence -list of traits of structures that make the bacteria to cause disease
Collagen (digested by what enzyme and definition)
-collagenase -body's chief structural protein
contagious disease
-communicable disease that is easily transmitted from a reservoir or patient -no spread from one host to another, and diseased patients are not a source of contamination for others
virulence
-degree of pathogenicity -is the relative ability of a pathogen to infect a host and cause a disease
Hyaluronidase (what digest and what helps bacteria to do)
-digest hyaluronic acid -extracellular matrix prevent bacteria to enter -> if bacteria able to digest the glue (hylaruonic acid between cells), it would be able to enter and cause disease
Following infection, a sequence of events called the_(term and what happens within it in broad sense) occurs
-disease process -How progress since they are introduced and become a disease -Signs of disease and growth of population of pathogens
enterotoxins
-exotoxin -affect cells lining the gastrointestinal tract
cytotoxins
-exotoxin -kill host cells in general or affect their function
neurotoxins
-exotoxin -specifically interfere with nerve cell function
axenic
-free of microbes -Sites that are free of any microbes
Reasons for the release of endotoxins (3)
-gram negative divide -gran negative naturally die or treated with antibiotics -gram negative is digested by phagocytic cells
Microbial contaminants include _ (3)
-harmless resident and transient members of the normal microbiota, as well as pathogens.
a less virulent organism_(include example conditions) causes a disease
-include opportunistic pathogens -only in a weakened host or presented in overwhelming numbers
Mechanical vectors (definition, examples)
-insects that we encounter more frequently-> they carry microorganisms on their bodies -vectors are not required as hosts by the pathogens they transmit; such vectors only passively carry pathogens to new hosts on their feet or other body parts. -ex: flies, roaches
Foodborne transmission (definition and examples)
-involves pathogens in and on foods that are poorly processed, undercooked, or poorly refrigerated. -ex: Poultry, seafood, meat
direct contact transmission
-involves person-to-person spread by bodily contact. -ex: handshaking, kissing, sexual intercourse, bites, scratching, touch animal reservoir, from mother to baby through placenta, self-contagion
Airborne transmission (definition and contamination range and example)
-involves the spread of pathogens to the respiratory mucous membranes of a new host via an aerosol, a cloud of small droplets and solid particles suspended in the air. -Spread of pathogens farther than 1 meter from its source -Ex: dust particles
Prodromal period (definition and signs and symptoms)
-is a short time of generalized, mild symptoms such as malaise, that precedes illness -Vague, general symptoms that proceed to the step 3
pandemic (definition and level)
-is an epidemic occurring on more than one continent. -global level
epidemic (when we can obtain it and definition)
-once we know an expectation of a disease based on history -Whenever a disease occurs at a greater frequency than normal for a population or area -occur at greater normal frequency above the expected number
Waterborne (important to spread what kind of diseases including what examples of diseases, examples, how water can act)
-is important in the spread of many gastrointestinal pathogens -including giardiasis and cholera. -Contaminated water, which lasts long period of time -ex: steams and swimming pools -water can act as reservoir or as a vehicle of infection
Illness (definition, which types of disease end here, immune system response to it, amount of pathogens, and symptoms and signs)
-is the most severe stage, when signs and symptoms are most evident (most intense). -Fatal diseases end at this stage. -Immune system has not responded to pathogens yet -greatest number of pathogens -Most severe signs and symptoms
Vehicle transmission
-is the spread of pathogens via air, drinking water, and food, as well as bodily fluids being handled outside the body. -transportation or deliver diseases into our bodies
Decline (definition and signs and symptoms)
-is the stage during which the patient's body gradually returns to normal as the immune response and any medical treatments vanquish the pathogen. -signs and symptoms decrease
Incubation period (definition, length determined by_, signs and symptoms)
-is the time between an infection and occurrence of the first symptoms. -When bacteria introduced -Length of incubation period depends on the virulence of the infective agent, the infective dose (initial # pathogens), the state and health of the patient's immune system, the nature of the pathogen and its reproductive time, and the site of infection -No signs or symptoms
why the respiratory tract is more infected than the gastrointestinal tract?
-it does not have the acidic pH that the gastrointestinal tract has, which helps to prevent the entrance of microorganisms -Respiratory tract is the most common side of entry because does not have any characteristic that makes it hard to the bacteria to get in
how ligands are called in bacteria? how they are called in viruses?
-ligands are called adhesin on bacteria and attachment proteins on viruses
Nosocomial infections
-nosocomial diseases are acquired by patients or staff in health care facilities. -Infections acquired while in a health care facility
Biological vectors (serve for, type, how pathogen enter host, example)
-not only transmit pathogens; they also serve as hosts for the multiplication of a pathogen during some stage of its life cycle -biting animals or arthropods (feed on you) -Enter host through bite -Ex: lice, mites, mosquitoes, ticks
incidence (definition and question)
-number of new cases of a disease in a given area during a given period of time -how many new cases of a disease?
Indirect contact transmission
-occurs when pathogens are spread from one host to another via fomites, inanimate objects that are inadvertently used to transfer pathogens. -In contact with things that were contaminated by infected person -These include needles, toothbrushes, tissues, toys, coins, drinking glasses, and other objects that can harborb or transmit pathogens.
pathogen
Any parasite that cause a disease
Analytical epidemiology (what it seeks to determine and how they figure out)
-seeks to determine the probable cause of a disease, its mode of transmission, and possible means of prevention. -retrospective: they attempt to identify causation and mode of transmission after an outbreak has occurred
what are the two manifestations of a disease?
-signs -Symptoms
if a person is assymptomatic, does it mean that they are healthy?
-someone can be sick but nothing that they perceive -but they do have some change (disease) that they cannot feel
parasite that allow their hosts to survive are most likely to_. Host that tolerate a parasite are more likely to_
-spread -reproduce
Fecal-oral infection (definition, contribution to spread diseases, and what spreads example)
-spread of pathogenic microorganisms in feces to the mouth, such as results from drinking sewage-contaminated water -infection is a major source of disease in the world, as certain worms and enteroviruses shed in the feces enter the gastrointestinal system
what is the function of the information concerning about a disease within populations recovered by epidermiologists?
-take steps to reduce the number of cases -improve the health of individuals within a community
Convalescence (definition, signs and symptoms, length depends on_)
-the patient recovers and tissues are repaired. -No signs or symptoms -The length depends on amount of damage, nature of pathogen, site of infection, and overall health of patient
antitoxins
-the way the body protects from toxins -antibodies that the host forms to bind with and destroy or neutralize toxins.
phagocyte (what it is and what it needs to grasp a microbe)
-type of immune cell that can eat or phaogocytose a microorganism-> by extending out the cell membrane to around the bacteria -to be able to grab the bacteria, immune cell needs to attach to the bacterial surface
Incomplete Phagocytosis steps
1. Attachment 2. Ingest (moves inside the cell) 3. Failure: : when bacteria is inside the immune cell; inside the immune cell has lysosome, so lysosome should dump all the digestive enzymes on the bacteria. some bacteria prevent fusion with lysosome-> so bacteria can reproduce inside of the immune cell. blocks the enzymes that are secreted the lysozome to dump into the bacteria
Describe the broad action of coagulase and kinase (3 steps)
1. Bacteria produce coagulase 2. Clot forms 3. Bacteria later produce kinease, dissolving clot and releasing bacteria
List the stages of infectious disease (5) (disease process)
1. Incubation period 2. Prodromal Period 3. Illness 4. Decline 5. Convalescence
Describe the broad action of hyaluronidase and collagenase (3 steps)
1.Invasive bacteria reach epithelial surface 2. Bacteria produce hyaluronidase and collagenase 3. Bacteria invade deeper tissues
what are the three factors that exist in a healthcare facility that make it prone to nosocomial infections? (describe them)
1.Presence of microorganisms in hospital environment (because you put sick people in the same place and includes antimicrobial resistant agents) 2. Immunocompromised patients (weakened immune system of patients that are ill or sick->more susceptible to opportunistic infections) 3. Transmission of pathogens between staff and patients and among patients (from staff and visitors, to patients, and even from one ...
sporadic
A disease is considered sporadic when only a few scattered cases occur.
what is an example of a syndrome?
AIDS
how is a way to prevent infections using the knowledge of ligands?
Ability to change or block the Bacterial adhesin or virus protein (ligand) or its receptor can prevent infection
Virulence factors contribute to an organisms virulence
Adhesion factors Biofilms - Do not attach directly but form sticky web (attach to other bacteria). Extracellular enzymes Toxins Antiphagocytic factors
Does infections always results in diseases?
An infection may or may not result in disease.
Disease
Any adverse internal conditions severe enough to interfere with normal body functioning
communicable (source of microbe, way of transmission)
Any infectious disease that come either directly or indirectly from another host
An anxenic environment is one that_ A. Exists in the human mouth B. Contains only one species (human specie) C. Exists in the human colon D. both a and c
B
Which of the following is FALSE concerning microbial contaminants? a. contaminants become opportunistic pathogens b. Most microbial contaminants will eventually cause harm c. contaminants may be a part of the transient microbiota d. Contaminants may be introduced by a mosquito bite
B
Which of the following phrases describe a contagious disease? a. a disease arising from fomites b. a disease that is easily passed from host to host in aerosol c. a disease that arises from opportunistic, normal microbiota d. Both a and b
B
An axenic environment is one that_ a. exists in the human mouth b. contains only one species c. exists in the human colon d. both a and b
B contains only one species
Ex of organism that is mutualistic?
Bacteria in human colon
CDC
Centers for Disease Control and Prevention
to determine prevalence and incidence, endemic, sporadic, epidermic, or pandemic of a disease, a good record must be kept. where those records are obtained and sent by health departments about infectious diseases?
Centers for Disease Control and Prevention in Atlanta, Georgia, which is the headquarters and clearinghouse for national epidemiological research
Toxins
Chemicals that harm tissues or trigger host immune responses that cause damage
what are the three ways of transmission?
Contact transmission Vehicle transmission Vector transmission
what are the three approaches of epidemiology that epidemiologists use to conduct research to study the dynamics of disease in populations? (3)
Descriptive epidemiology Analytical epidemiology Experimental edpiemiology
when a disease results?
Disease results only if the invading pathogen alters the normal functions of the body
Describe in which organisms adhesion factors are found (2) and the types
Found on viruses (attachment proteins) and many bacteria (adhesins)
what are the signs and symptomps part of the syndrome of AIDS?
HIV+, Low CD4 count (white blood cell count), rare and opportunistic infections
Which of the following is an example of an endotoxin: A. Neurotoxin (exotoxin) B. Coagulase C. Streptokinase D. Collaganase E. Lipopolysaccharide/ Lipid A
E. Lipopolysaccharide
Two types of toxins
Exotoxins Endotoxins
Phagocystosis blocked by a capsule fails at which step of phagocytosis?
Fails at attachment step
How ligands are used for specificity of bacteria and virus?
Interaction of adhesin or attachment protein (ligand) with host receptor can determine specificity for host cells
adhesion is accomplished through the use of_
It is accomplished via a variety of structures or chemical receptors called adhesion factors
who is the father of epidermiology and describe briefly what he did?
John Snowman (tracked Chloera in London by looking population as a whole-> mapped it)
Endotoxins (other name, where found, who produce, definition, and what they can cause)
Lipid A (lipopolysaccharide) LPS (structural component that is part of the outer membrane that cause damage in our body) Gram - is released from the outer cell wall of dead and dying Gram-negative bacteria can cause systemic shock and other fatal effects.
What is a common part where you can find microbes?
Many parts of our body are covered by microbes
Each week the CDC reports the number of cases of most of the nationally notifiable diseases in the_
Morbidity and Mortality Weekly Report (MMWR)
what is the major route of entry and that normal microbiota will establish on?
Mucous membranes, especially respiratory tract
Nonliving reservoirs (4 types)
Nonliving reservoirs of infection include soil, water, food, and objects.
Opportunistic pathogens
Normal microbiota or other normally harmless microbes that can cause disease under certain circumstances
occurrence can be evaluated also by_ (2)
Occurrence also evaluated in terms of frequency: time (week, day, month, year) -geographic distribution
What determines if infection progresses to disease state?
Pathogenicity Virulence
adhesion is required to_
Required to successfully establish colonies within the host
How can scientists know the normal prevalence of a given disease?
Scientists record every case of the disease so they they will have a "baseline" prevalence, which then becomes the expected prevalence for each disease
Reservoirs of infection
Sites where pathogens are maintained (infectious) as a source of infection are termed reservoirs of infection
adhesion factors allow perform other virulence factor called_
Some pathogens interact to produce a sticky biofilm that adheres to a surface and allows bacteria to thrive.
Adhesion factors include _(2)
Specialized structures Attachment proteins
which diseases are the most common?
respiratory diseases due to the fact that the respiratory tract is the very easy to enter and stay since does not have any characteristic that makes it hard to the bacteria to get in
Fever, swelling, rash, and redness would be a sign or symptom?
sign
what are the most common routes of entry?
skin and mucous membranes
Can microbiota sick us?
sometimes they can under the right conditions, which would be opportunistic infections
Contact transmission
spread of pathogens form one host to another by direct contact, indirect contact, or respiratory droplets
