chp 2

Here is a Quizlet-ready flashcard set for Chapter 2: Concepts of Infectious Disease

based only on Dr. Eudy’s Chapter 2 PowerPoint. Each card is formatted **Term

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Pathogen

Any bacterium virus fungus protozoan or helminth (worm) that causes disease in humans

Pathogenicity

The ability of an organism to cause disease; some microorganisms are more pathogenic than others

Human microbiota (flora)

The collection of all microbes on the human body

Colonization

The ability of a microbe to stay attached to a body surface and replicate

Adhesins

Structures or factors that enable microbiota to attach to host cells

Infection

Occurs when a pathogen or parasite enters and begins to grow on the host

Asymptomatic infection

An infection in which the infected individual does not develop symptoms; many if not most infections are asymptomatic

Disease

Occurs when a patient develops symptoms; a disruption of the normal structure or function of a body part organ or system recognized by characteristic signs and symptoms

Acute infection

An infection in which symptoms develop and resolve rapidly; the common cold is an example

Chronic infection

An infection in which symptoms develop gradually and resolve slowly; tuberculosis and HIV are examples

Primary pathogen

A pathogen that causes disease after infection in a healthy host; rapidly reproduces or increases in number and has moderate to high virulence; influenza is an example

Opportunistic pathogen

A pathogen that primarily affects immunocompromised individuals and generally has low virulence; Pseudomonas and Pneumocystitis are examples

Latent infection

An infection in which the pathogen lives lifelong in the host; examples include herpes HPV HIV EBV and CMV

Virulence

The level of harm caused by a pathogen following infection

Lethal dose

Amount of a pathogen needed to kill

Infectious dose

Amount of a pathogen needed to cause infection

Virulence factors

Aspects of a pathogen that contribute to virulence including toxins enzymes adhesins and an anti-phagocytic capsule

Toxins

Virulence factors that contribute to the harm caused by a pathogen

Enzymes

Virulence factors that can contribute to the ability of a pathogen to cause harm

Anti-phagocytic capsule

A virulence factor that helps a pathogen resist phagocytosis

Host range

The animals a pathogen can infect and produce disease in

Narrow host range

A host range in which an organism can infect only one type of host; Salmonella enterica serovar Typhi infects humans only and causes typhoid fever

Broad host range

A host range in which an organism can infect multiple types of animals; Salmonella enterica serovar Typhimurium infects humans and other animals

Infectious disease

A disease caused by a bacterial viral or parasitic pathogen that can be transferred from one host to another

Sign

An objective marker of disease that can be observed during examination; examples include a fluid-filled rash a fever of 102°F and most vital signs

Symptom

A subjective indicator of disease experienced by the person; examples include pain and fatigue

Syndrome

A collection of signs and symptoms that occur together and collectively characterize a condition

Host response to infection

Many signs and symptoms of disease result from the host response because cells can damage nearby host tissue while killing microbes; this is common with influenza and COVID-19 cytokine storms

Sequelae

Pathological consequences that may develop after a disease has resolved

Rheumatic fever

An example of a sequela in which the immune response to strep throat can cause heart damage weeks after the infection has resolved

Incubation stage

First stage of an acute infectious disease when the individual is first infected

Prodromal stage

Stage when initial symptoms such as fatigue and malaise appear

Illness stage

Stage when the patient is the most sick and the pathogen count is high

Decline stage

Stage when the immune response begins to work

Convalescence stage

Stage when the patient begins to feel better and the pathogen count decreases

Long-term stage

Stage in which the immune response hopefully produces memory lymphocytes

Morbidity

The rate of illness due to a disease

Mortality

The rate of death due to a disease

High morbidity and low mortality

A disease pattern in which many people become ill but relatively few die; the common cold is an example

Low morbidity and high mortality

A disease pattern in which fewer people become ill but the disease has a high rate of death; rabies is an example

Direct contact transmission

Spread of organisms directly from person to person through touching kissing sex or respiratory droplet contact

Indirect transmission

Spread of pathogens through a living or nonliving intermediary

Airborne transmission

A form of indirect transmission in which pathogens spread through the air

Fomite

An inanimate object that can indirectly transmit pathogens

Vehicle transmission

Indirect transmission through substances such as food water or feces

Fecal-oral transmission

Transmission involving fecal material reaching the oral or gastrointestinal route

Vector

A living intermediary such as a tick or mosquito that can transmit a pathogen

Horizontal transmission

Transfer of an infectious agent from one person or animal to the next; the common cold is an example

Vertical transmission

Transfer of an infectious agent from parent to offspring; TORCH infections are an example