Class 3 - Infectious Disease Flashcards
What are the 2 basic objectives that all living creatures share in life?
1) Survival
2) Reproduction
Illnesses caused by the invasion of the human body by pathogen and microorganisms can produce harmful and potentially lethal consequences.
Infectious Diseases
Organisms so small they are invisible to the naked eye and can only be seen with a microscope. They can be pathogens or non-pathogens.
Microorganisms
T/F - All microbes are microorganisms, but not all microorganisms are microbes.
True
The presence and multiplication within a host of another living organism with subsequent injury to the host.
Infection
The ability of an organism to enter, multiply, and survive in a host.
Infectivity
Any organism capable of supporting the nutritional and physical growth requirements of another organism. For example, humans supporting the growth of microorganisms.
Host
The act of establishing a presence within a host.
Colonization
The degree of pathogenicity or disease producing potential of an invading organism.
Virulence
An organism so virulent that it is rarely found in the absence of disease.
Pathogen
A multitude of non-harmful bacteria inhabiting the internal and external exposed surfaces of the human body.
Microflora
Free living organisms that obtain nutrition from dead or decaying organic materials in the environment.
Saprophytes
An organism which produces an infectious disease only when the health and immunity of the host has been severely compromised.
Opportunistic Pathogen
What are the 3 types of interactions between host and the colonizing microorganisms?
1) Commensalism
2) Mutualism
3) Parasitic
A type of interaction where the colonizing organism benefits and the host is not adversely affected by it.
Commensalism
Locations of ____________ in the human body include:
- Skin
- Nose/Pharynx
- Mouth
- Colon/Rectum
- Vagina/Distal Urethra/Perineum
Microflora (Commensal Flora, Normal Flora & Resident Microbiotica)
A type of interaction where the colonizing organism and the host both derive benefits.
Mutualism
A type of interaction where the colonizing organism benefits and the host gains nothing or sustains injury.
Parasitic
Protein particles that lack any kind of demonstrable genetic material and they are mutated forms of a normal host protein. They may affect other normal proteins and alter them.
Prions
Prions aggregate in the _____ and form _______.
Brain
Plaques
What are 3 incurable and transmissible degenerative neurological diseases prions have been identified in?
1) Creutzfeldt-Jakob Disease
2) Kuru
3) Mad Cow Disease
T/F - Defective proteins known as a prions are not inherited.
False - Defective proteins known as a prions MAY BE inherited.
Cannibalism has also been implicated as a transmission mechanism of ______.
Prions
It is hypothesized that humans can acquire prions by eating animals that are infected by a prion disease like ____________.
Mad Cow Disease
Because prions lack reproductive and metabolic functions, the current antimicrobial agents are useless against them. Therefore, treatment is __________.
Palliative
________________ neurological diseases are characterized by the following:
- Slowly progressive
- Non-inflammatory neuronal degeneration
- Lead to loss of coordination (ataxia), dementia, & death
- Ranging from months to years
Transmissible Degenerative
Name 4 agents of infection that meet the following criteria:
- Combine the characteristics of viruses and bacteria
- Are obligate intracellular pathogens like viruses
- Most produce a rigid peptidoglycan cell wall, reproduce asexually, and contain RNA/DNA like bacteria
1) Rickettsia
2) Chlamydia
3) Coxiella
4) Mycoplasma
Tiny gram negative bacteria that live inside a host cell (obligate intracellular parasites) and they are transmitted by insect vectors.
Rickettsia
Which agent of infection can cause disease like typhus and Rocky Mountain Spotted Fever, as well as a typical rash and small hemorrhages.
Rickettsia
A primitive organism related to bacteria that lack many of the enzymes needed for metabolic processes. Transmitted directly between susceptible vertebrates without an intermediate arthropod host.
Chlamydia
It causes and very common sexually transmitted infection, which can lead to pelvic inflammatory disease and sterility in women. Infants born to infected mothers can develop eye infections and pneumonia.
Chlamydia
Infects a variety of animals and in humans, produces an illness called Q fever.
Coxiella
An illness caused by coxiella that presents with flu-like symptoms and cause progress to become systemic, affecting the heart, lungs, and GI.
Q Fever
Capable of independent replication and commonly cause pneumonia. These organisms lack a cell wall, and therefore they are no affected by antimicrobial drugs.
Mycoplasmas
Free living eukaryotic saprophytes found in every habitat on earth and some are part of the normal human microflora. Few are capable of causing disease in human, and most of these are limited infections of skin and subcutaneous tissue.
Fungi
A harmless fungus normally present on the skin. It may cause infection in the oral cavity and is a common cause of vaginal infection.
Candida
T/F - Candida can become opportunistic in immunosuppressed patients.
True
What are the 2 types of fungi?
1) Yeast
2) Molds
A type of fungi that are single celled organisms about the size of red bloods cells. They reproduce asexually through a budding process.
Yeast
A type of fungi that grows in long filaments called hyphae.
Molds
Yeasts and molds can reproduce disease in humans only if they grow at the __________ of the infected body site.
Temperature
Yeasts and molds produce a rigid cell wall layer that is chemically unrelated to the peptidoglycan of bacteria, and is therefore not susceptible to the effects of ________.
Antibiotics
A fungal infection resulting in a scaly rash that is contagious and is treated by over the counter medications.
Athletes Foot
Designate members of the animal kingdom that infect and cause disease in other animals.
Parasites
The following are all examples of _________:
- Protozoa
- Helminths
- Arthropods
Parasites
A type of parasite classified as unicellular eukaryotes that may reproduce sexually or asexually and most are saprophytes. Some are pathogenic to humans and produce diseases, such as malaria. Transmission is from host to host sexually or indirectly.
Protozoa
A type of parasite commonly referred to as worms that reproduces sexually. Transmission is via ingestion of fertilized eggs or the penetration of roundworms, tapeworms, and/or flukes through the skin.
Helminths
A type of parasite known as vectors of disease, such as ticks, mosquitos, biting flies, lice, fleas and/or mites. They infest the external body surfaces and cause localized tissue damage or secondary inflammation. Transmission is via direct contact.
Arthropods
The study of factors, events, and circumstances that influence the transmission of infectious disease in human populations. Ultimate goal is the interruption of the spread of infectious disease and its eradication.
Epidemiology
____________ focus on:
- Incidence of disease
- Prevalence of disease
- Source of infection
- Portal of entry
- Site of infection
- Virulence factors
- Signs and symptoms
- Clinical course of a disease
Epidemiology
Refers to the host, object, location, or substance from which an infectious agent is acquired and involves different modes of transmission.
Source of Infection
A mode of transmission acquired from the host’s own microbial flora, as in the case of opportunistic infection.
Endogenous
A mode of transmission acquired from sources in the external environment, such as water, food, soil, and air.
Exogenous
Transmission of illness from mother to child during gestation is an example of a ________ infection.
Congenital
A mode of transmission occurring from transfer of microbes by physical contact, which can be direct or indirect.
Contact Transmission
A mode of transmission occurring when microbes are spread across a short distance (less than 1 metre) by droplets. This happens after someone sneezes or coughs.
Droplet Transmission
A mode of transmission occurring when microbes are transmitted by air currents across long distances (more than 1 metre) and are carried on evaporated droplets or dust particles.
Airborne Transmission
A mode of transmission in which animals or biting arthropods transmit microbes to humans.
Vector Born Transmission
A mode of transmission occurring when infection is transmitted by a contaminated source, such as food, water, medication, invasive medical equipment, and/or bodily fluids.
Vehicle Born Transmission
Type of infection acquired during hospitalization or from a health care facility.
Nosocomial Infections (Hospital Acquired Infections)
Type of infection acquired outside of health care settings.
Community Acquired Infections
The process by which a pathogen enters the body and gains access to susceptible tissue.
Portal of Entry
A term referring to any disruption in the integrity of the body’s surface barrier (skin or mucous membrane) creating a potential site for invasion.
Penetration
__________ creating a potential site for invasion can happen from:
- Abrasions, burns, penetrating wounds
- Medical procedures
- Primary infectious processes producing surface lesions
- Arthropod bite
Penetration
When pathogens are transmitted directly from infected tissue or secretions to exposed, intact mucous membranes.
Direct Contact
______ contact includes:
- Sexual contact
- Congenital infections
Direct
A type of infection when a pathogen crosses the placenta to infect a fetus during birth when the baby comes in contact with infected vaginal secretions.
Congenital Infections
A term referring to the entry of an infectious agent through the oral cavity and GI tract. Could involve contaminated food/water or happen through breast feeding.
Ingestion
A term referring to the entry of an infectious agent through the respiratory tract, such as droplet infection or airborne infection.
Inhalation
Refers to the part of the body that is infected. A _____ infection occurs in one body part and a ________, or generalized infection involves the whole body.
Site of Infection
Local
Systemic
The capacity of a microorganism to cause disease and make you sick.
Pathogenicity
__________ is based on the following:
- Invasive qualities
- Toxic qualities
- Adherence to tissue
- Ability to avoid host defences
Virulence
________ precautions include hand washing, wearing gloves, and personal protective clothing. __________ is the most effective way to stop the spread of the most common pathogens.
Universal
Hand Washing
________ or source of infection must be located and removed. Portal of exit of microbes should be ______. Knowledge of mode of __________ of a pathogen is essential to blocking its spread.
Reservoir
Blocked
Transmission
Some other universal __________ include:
- Reducing host susceptibility by immunization, proper diet, and nutrition
- Adequate cleaning of surroundings and clothing
- Use of disinfectants and antiseptics to destroy microorganisms
- Sterilization of fomites by methods such as autoclaving
Precautions
Refers to the collection of signs and symptoms expressed by the host during the disease course. This is an outward expression of the struggle between invading organisms and the hosts response of inflammation and immune reaction.
Symptomatology (Clinical Picture, Disease Presentation)
Can be specific and reflect the site of infection or non-specific and shared by many diverse infectious diseases. They can also be obvious or covert.
Signs & Symptoms
Examples of ______________ include:
- Fever and chills
- Increased pulse and respiratory rates
- Aches, pain, or tenderness
- Fatigue and loss of energy
- Loss of appetite, nausea, vomiting, and diarrhea
- Rash, redness, and swelling of a body part
- Sores on mucous membrane
Signs & Symptoms
What are the 5 phases of the disease course?
1) Incubation Period
2) Prodromal Stage
3) Acute Stage
4) Convalescent Stage
5) Resolution Stage
The first phase of the disease course when the pathogen begins active replication without producing symptoms.
Incubation Period
The second phase of the disease course characterized by the initial appearance of symptoms.
Prodromal Stage
The third phase of the disease course when the host experiences maximum impact of the infectious process and has the most symptoms.
Acute Stage
The fourth phase of the disease course involving containment of infection, progressive elimination of the pathogen, repair of damaged tissue, and resolution of associated symptoms.
Convalescent Stage
The final phase of the disease course involving total elimination of the pathogen from the body with no residual signs and symptoms.
Resolution Stage
Chronic infections have continuous signs and symptoms for months or years without a __________ stage.
Convalescent
A type of illness that progresses from infection to resolution without clinically apparent symptoms.
Subclinical (Sub-Acute) Illness
Term referring to when the prodromal phase is gradual.
Insidious
Term referring to abrupt onset of illness with little or no prodromal phase.
Fulminant
________ of an infectious disease is based on:
- History
- Physical examination
- Culture
- Serology
Diagnosis
__________ of an infectious disease can involve:
- Antimicrobial agent
- Immunotherapy
- Surgical intervention
Treatment
