Health and Disease Overview
51 Questions
3 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What disease is spread primarily via mosquitoes?

  • Common cold
  • Rabies
  • West Nile Virus (correct)
  • Measles

Which disease is characterized by a high contagious rate and a majority of the population being vaccinated?

  • Measles (correct)
  • Herpes
  • Rabies
  • Common cold

Which disease is known as a serious and rare illness contracted through animal bites?

  • Rabies (correct)
  • Common cold
  • Herpes
  • West Nile Virus

What is the most telling characteristic of herpes infections?

<p>Contagious sores on the body (B)</p> Signup and view all the answers

Which of the following diseases is highly contagious and usually occurs in seasons?

<p>Common cold (B)</p> Signup and view all the answers

What is the primary role of resident microbiota in the human body?

<p>To fend off other pathogens (D)</p> Signup and view all the answers

Which factor is NOT typically associated with causing disease?

<p>High nutrient intake (D)</p> Signup and view all the answers

Which of the following defines a pathogen?

<p>A microbe that can cause disease (A)</p> Signup and view all the answers

How does microbial antagonism protect the host?

<p>By competing with pathogens for resources (C)</p> Signup and view all the answers

What aspect defines virulence in pathogens?

<p>Degree of pathogenicity and damage caused (A)</p> Signup and view all the answers

What does the term 'infectious dose (ID50)' refer to?

<p>Number of microorganisms needed to produce disease in 50% of test subjects (C)</p> Signup and view all the answers

What do opportunistic pathogens require to cause disease?

<p>Compromised host defenses (B)</p> Signup and view all the answers

Which of the following is an example of a benefit provided by normal microbiota?

<p>Production of vitamins (D)</p> Signup and view all the answers

What does the term 'pathogenesis' specifically refer to?

<p>The development of disease (B)</p> Signup and view all the answers

Which statement about transient microbiota is correct?

<p>They are temporary residents of the body (D)</p> Signup and view all the answers

What does the incidence of disease measure?

<p>Number of new cases over a certain time period (D)</p> Signup and view all the answers

Which type of epidemic arises from a single source of infectious agents?

<p>Point-source epidemic (D)</p> Signup and view all the answers

What characterizes a pandemic?

<p>Spread of disease across continents (C)</p> Signup and view all the answers

Emerging Infectious Diseases (EIDs) are primarily characterized as:

<p>Newly identified microbes (D)</p> Signup and view all the answers

Which term is used to describe occasional cases of a disease reported at irregular intervals?

<p>Sporadic disease (C)</p> Signup and view all the answers

What is the mortality rate a measurement of?

<p>Number of deaths in a population due to a specific disease (A)</p> Signup and view all the answers

Which of the following is an example of a re-emerging disease?

<p>Tuberculosis (A)</p> Signup and view all the answers

What does the term 'index case' refer to in epidemiological investigations?

<p>First patient found during an investigation (A)</p> Signup and view all the answers

Which factor is NOT considered a contributing factor to emerging infectious diseases?

<p>Improved sanitation practices (B)</p> Signup and view all the answers

Which of the following diseases is considered endemic to a particular geographic area?

<p>Valley fever in South America (A)</p> Signup and view all the answers

Which step follows the adhesion process in the establishment of an infection?

<p>Evading host defenses (B)</p> Signup and view all the answers

What type of strategies do pathogens use to evade phagocytes?

<p>Producing antiphagocytic factors (A)</p> Signup and view all the answers

What is a characteristic of exotoxins compared to endotoxins?

<p>Exotoxins can induce specific host defenses. (B)</p> Signup and view all the answers

Which type of infection remains localized yet can exert systemic effects through toxins?

<p>Focal infection (D)</p> Signup and view all the answers

What is the primary mode of entering the human body for most pathogenic microbes?

<p>Mucous membranes (A)</p> Signup and view all the answers

In what way do leukocidins function in the pathogen's defense mechanism?

<p>They kill white blood cells. (A)</p> Signup and view all the answers

What differentiates primary infections from secondary infections?

<p>Secondary infections occur after a primary infection by a different microbe. (C)</p> Signup and view all the answers

Which portal of exit do pathogens primarily use to spread through respiratory droplets?

<p>Salivary secretions (D)</p> Signup and view all the answers

Which of the following best describes the role of quorum sensing in pathogens?

<p>It allows for communication among microbes to coordinate infection. (B)</p> Signup and view all the answers

What is the main function of exoenzymes secreted by infectious agents?

<p>To cause direct tissue damage. (B)</p> Signup and view all the answers

Which of the following statements accurately defines endotoxins?

<p>They remain in the bacterial membrane until the bacteria die. (D)</p> Signup and view all the answers

What typically triggers a secondary infection following a primary infection?

<p>Existing damage caused by the first pathogen (D)</p> Signup and view all the answers

What characterizes chronic infections compared to acute infections?

<p>Chronic infections progress and persist over a long period. (C)</p> Signup and view all the answers

Which of the following is a sign that can be objectively measured by a non-patient observer?

<p>Tachycardia (A)</p> Signup and view all the answers

Which type of infection is characterized as asymptomatic or subclinical?

<p>Carriers (B)</p> Signup and view all the answers

What term describes the long-term or permanent damage caused by an infectious disease?

<p>Sequelae (B)</p> Signup and view all the answers

What is the main difference between a reservoir and a source of infection?

<p>A reservoir is the primary habitat, while a source is where an infection is acquired. (A)</p> Signup and view all the answers

Which type of vector is required for the life cycle of a pathogen?

<p>Biological vector (A)</p> Signup and view all the answers

How do horizontal and vertical transmission differ?

<p>Horizontal transmission occurs within a population, while vertical is from parent to offspring. (A)</p> Signup and view all the answers

Which disease is primarily categorized as noncommunicable?

<p>Valley fever (B)</p> Signup and view all the answers

What is the goal of Koch's postulates in studying infectious diseases?

<p>To identify the causative agent of diseases. (D)</p> Signup and view all the answers

What is the most common way to acquire healthcare-associated infections (HAIs)?

<p>Via contaminated hands and medical equipment. (D)</p> Signup and view all the answers

Which of the following pathogens is known to enter a latent stage?

<p>Syphilis (D)</p> Signup and view all the answers

Which type of carrier is described as not showing any symptoms but can still infect others?

<p>Incubating carrier (D)</p> Signup and view all the answers

Which statement about zoonotic infections is incorrect?

<p>Zoonotic infections can only be transmitted through bites. (C)</p> Signup and view all the answers

What is an example of indirect transmission through vehicles?

<p>Ingestion of contaminated water. (B)</p> Signup and view all the answers

Flashcards

Colonization

Microbes living in or on the human body without causing disease.

Infection

When pathogenic microbes enter tissues, multiply, and disrupt defenses.

Disease

A disruption of normal health, often related to an infection but can have other causes like genetics, environment, malfunctioning systems.

Pathogen

A microbe capable of causing disease.

Signup and view all the flashcards

Virulence

The degree of pathogenicity of a microbe – how easily it causes disease.

Signup and view all the flashcards

Virulence factor

Characteristics or structures of a microbe that contribute to its ability to cause disease (toxin production, harm response).

Signup and view all the flashcards

Normal Microbiota

The microbes that are resident in/on various body sites, aiding in health by competing against pathogens.

Signup and view all the flashcards

ID50

The infectious dose required to cause infection in 50% of test hosts.

Signup and view all the flashcards

Opportunistic Pathogen

A microbe that causes disease only when the host's defenses are weakened or when it is in an unusual place in the body.

Signup and view all the flashcards

Pathogenesis

The development of a disease.

Signup and view all the flashcards

Morbidity and Mortality Report

A weekly publication by the CDC that reports on the prevalence of diseases in the US.

Signup and view all the flashcards

Prevalence of disease

The total number of existing cases of a disease in a population at a given time.

Signup and view all the flashcards

Incidence of disease

The number of new cases of a disease occurring in a population during a specific time period.

Signup and view all the flashcards

Mortality rate

The number of deaths in a population due to a specific disease.

Signup and view all the flashcards

Point-source epidemic

An epidemic where all cases of a disease are linked to a single source of infection.

Signup and view all the flashcards

Common-source epidemic

An epidemic where cases of a disease are linked to a common source of infection that may occur over some time.

Signup and view all the flashcards

Propagated epidemic

An epidemic where infection spreads from person to person and is sustained over time.

Signup and view all the flashcards

Pandemic

An epidemic that spreads across continents.

Signup and view all the flashcards

Index case

The first patient identified in an epidemiological investigation.

Signup and view all the flashcards

Endemic

A disease that occurs at a relatively steady frequency in a particular geographic area over a long period.

Signup and view all the flashcards

Portal of entry

The specific route a pathogen takes to enter the body.

Signup and view all the flashcards

Parenteral route

Pathogens deposited directly into the tissues beneath the skin.

Signup and view all the flashcards

Inhalation (airborne)

Pathogens enter through the respiratory system.

Signup and view all the flashcards

Adhesion/Attachment

Process where pathogens attach to host tissues.

Signup and view all the flashcards

Establishment

Pathogens successfully survive and reproduce inside the host.

Signup and view all the flashcards

Evading Host Defenses

Pathogens avoiding the body's immune system.

Signup and view all the flashcards

Exoenzymes

Enzymes secreted by pathogens to break down and damage host tissues.

Signup and view all the flashcards

Exotoxins

Secreted proteins that are poisonous to host cells.

Signup and view all the flashcards

Endotoxins

Components of the outer membrane of gram-negative bacteria, released when the bacteria die.

Signup and view all the flashcards

Quorum sensing

Method of chemical communication between bacteria.

Signup and view all the flashcards

Portal of exit

Path by which pathogens leave the host.

Signup and view all the flashcards

Antiphagocytic factors

Substances produced by pathogens to prevent their destruction by phagocytes.

Signup and view all the flashcards

West Nile Virus

A serious viral disease spread through mosquito bites, often causing flu-like symptoms or neurological issues.

Signup and view all the flashcards

Herpes

A contagious viral infection causing cold sores or genital sores, often recurring in periods of stress or weakened immune system.

Signup and view all the flashcards

Rabies

A deadly viral disease transmitted via the bite of an infected animal, leading to neurological damage and ultimately death.

Signup and view all the flashcards

Common Cold

A highly contagious respiratory infection, typically caused by a virus, causing symptoms like sneezing, coughing, and runny nose.

Signup and view all the flashcards

Measles

A highly contagious viral disease causing a rash, fever, and respiratory issues, with a high vaccination rate.

Signup and view all the flashcards

Acute Infection

A sudden onset infection with short-lived effects. Often associated with rapid symptoms and recovery.

Signup and view all the flashcards

Chronic Infection

An infection that progresses and persists over a long period of time. Symptoms may be less severe but ongoing.

Signup and view all the flashcards

Sign (of disease)

Objective changes that can be observed and measured by someone other than the patient. More precise than symptoms.

Signup and view all the flashcards

Symptom (of disease)

Subjective evidence of disease as sensed by the patient. Only the patient can describe it.

Signup and view all the flashcards

Syndrome

A collection of specific signs and symptoms that define a particular disease.

Signup and view all the flashcards

Leukocytosis

A high white blood cell count, indicating the body is fighting an infection.

Signup and view all the flashcards

Leukopenia

A low white blood cell count, which can be a sign of an impaired immune system or a severe infection.

Signup and view all the flashcards

Carrier

A person or animal that is infected with a pathogen but does not show any signs of disease.

Signup and view all the flashcards

Latency

A dormant state of an infectious agent where it remains inactive for a period of time.

Signup and view all the flashcards

Sequelae

Long-term or permanent damage to organs or tissues caused by an infection.

Signup and view all the flashcards

Incubation Period

The time between initial exposure to a pathogen and the appearance of the first symptoms.

Signup and view all the flashcards

Prodromal Period

The time when the first notable symptoms of an infection appear.

Signup and view all the flashcards

Acute Period

The time when the infectious agent is most active and multiplying rapidly, leading to peak symptoms.

Signup and view all the flashcards

Convalescent Stage

The time when the patient's body is recovering from the infection and symptoms decline.

Signup and view all the flashcards

Reservoir (of a pathogen)

The natural habitat where a pathogen originates and persists.

Signup and view all the flashcards

Study Notes

Health and Disease

  • Colonization describes microbes living on or in the human body. Resident microbiota (normal flora) don't cause disease. They help defend against other pathogens, such as vitamin K. Transient microbiota come and go.
  • Infection occurs when pathogenic microbes penetrate host defenses, enter tissues, and multiply.
  • Disease is a deviation from normal health, characterized by disruption of body's functions. Factors include infections, genetics, aging, environmental agents, and malfunctions in systems or organs. This leads to infectious disease, a disruption of tissues or organs caused by microbes or their products.
  • Pathogens are microbes capable of causing disease. Pathology studies disease, etiology identifies its cause, and pathogenesis explains its development.

Normal Microbiota

  • Microbes can cross the placenta during childbirth.
  • The gut, skin, eyes, respiratory tract, urogenital system, and other areas are colonized by microbes, some of which are considered resident, and some transient. Some reside in tissues that were previously thought to be sterile, such as lungs, bladder, breast milk, and placenta.
  • The human microbiome project sequences biota of humans. Human cells have 21,000 protein-encoding genes; microbes inhabiting humans contain ~8 million. Healthy people harbor many potentially dangerous pathogens, though in low numbers. Studying changes in the microbiome helps in understanding disease.

Pathogens

  • True pathogens can cause disease in healthy individuals with normal immune systems.
  • Opportunistic pathogens cause disease in compromised hosts (weak immune systems) and when they colonize parts of the body not typically inhabited.
  • Virulence describes a pathogen's degree of pathogenicity, indicated by its ability to establish itself in a host and cause damage. Virulence factors are characteristics that enhance pathogenicity, such as contributing to toxin production. Microbes with smaller infectious doses are generally more virulent. An infectious dose is the number of organisms needed to cause disease in 50% of those inoculated; and a lethal dose the number of organisms needed to kill 50% of those inoculated..

Infection Process

  • Step 1: Entrance. Microbes enter the body through skin, mucous membranes, or the parenteral route (wounds, punctures).
  • Step 2: Attachment. Microbes adhere to host tissues using specific molecules called adhesions to establish themselves.
  • Step 3: Surviving host defenses. This stage involves avoiding host immune responses, such as those carried out by phagocytes (white blood cells). Antiphagocytic factors are virulence factors that help microbes avoid phagocytes.
  • Step 4: Causing disease. Microbes harm host cells directly through enzymes and toxins or indirectly inducing an excessive host response.
  • Step 5: Vacating the host. Pathogens exit the body through various portals like the respiratory tract.

Types of Disease

  • Localized. Microbes remain confined to a specific tissue; examples include boils and fungal skin infections.
  • Systemic. Infection spreads to multiple sites and tissue fluids; this usually involves the bloodstream and may include viruses, bacteria, and fungi.
  • Focal. When an infection spreads to other parts of a body from an initial local infection. Pathogens break loose and spread to other tissues or organs, like streptococcal pharyngitis, which can lead to scarlet fever if not controlled.
  • Mixed. Several agents establish disease simultaneously at the infection site.
  • Primary. The first infection that occurs.
  • Secondary. A second infection occurring in a host compromised by the primary infection. This has a different causative agent.

Acute vs. Chronic Infections

  • Acute infections: develop rapidly, have short-lived effects, and include examples like the flu.
  • Chronic infections: have a prolonged course and last for extended periods, such as Valley fever.

Disease Patterns

  • Endemic: a disease that exhibits relatively steady frequency over long periods in a particular region.
  • Epidemic: disease that occurs in a large number of individuals within a community or region in a short period.
  • Sporadic. A disease that occurs in scattered cases that are infrequent or irregular.
  • Pandemic: an epidemic that spreads across continents.

Reservoirs

  • Reservoirs are the primary habitats in the natural world from which outbreaks originate, such as humans, animals, water, or soil.
  • Living reservoir: these are mainly animals or humans that serve as sources where pathogens can persist.
  • Nonliving reservoirs: environmental sources where some pathogenic agents may reside.
  • Passive carriers: individuals or objects containing pathogens, which are then transferred to other hosts.
  • Chronic carriers: these individuals have latent infections and transmit pathogens without showing obvious signs or symptoms for a prolonged period.

Transmission

  • Horizontal transmission: spread of pathogens through contact or other means between individuals.
  • Vertical transmission: transmitted from parent to offspring (e.g., during pregnancy or childbirth.)
  • Direct contact: transmission of pathogens via physical contact between infected and uninfected individuals.
  • Indirect contact: transmission of pathogens via intermediary objects or vectors.
  • Vehicle transmission: pathogens are spread via contaminated inanimate objects, food, water, or air.
  • Vector transmission: pathogens are carried by insects and other living vectors, like flies and mosquitoes.

Healthcare-Associated Infections (HAIs)

  • Nosocomial infections are those acquired during a hospital stay. These infections result in a variety of methods, including faulty procedures, and contaminated instruments. Factors that contribute include the high number of pathogens present, and the compromised immune systems of patients.
  • Iatrogenic infections are HAIs due to medical procedures and treatments.
  • Control of HAIs involves reducing pathogens through aseptic techniques and maintaining sterile environments.

Koch's Postulates

  • Series of criteria to establish the causative agent of an infectious disease. This includes methods to isolate the agent, and to reproduce the disease using this agent in other animals.

Epidemiology

  • Epidemiology studies factors related to the rate, distribution, frequency, and frequency of disease and other health factors in a population. Diseases are studied through rates, incidence and prevalence.
  • Reportable diseases: some diseases are required by law or convention to be reported to health authorities.
  • Epidemiological statistics: measure of disease prevalence, incidence and mortality.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Microbe-Human Interactions (Ch 13 & 14) PDF

Description

Explore the concepts of colonization, infection, and disease in human health. This quiz covers the roles of normal and transient microbiota, as well as the factors that lead to infectious diseases. Understand the definitions and differences between pathogens, pathology, and etiology.

More Like This

Mycology and Fungal Infections Quiz
32 questions

Mycology and Fungal Infections Quiz

WellRoundedManticore avatar
WellRoundedManticore
Microbiology: Non-invasive Bacteria Infections
25 questions

Microbiology: Non-invasive Bacteria Infections

PraisingGyrolite6030 avatar
PraisingGyrolite6030
Microbiology and Infection
26 questions

Microbiology and Infection

FastFeynman avatar
FastFeynman
Infection and Infectious Agents
25 questions

Infection and Infectious Agents

AmazingJackalope avatar
AmazingJackalope
Use Quizgecko on...
Browser
Open
Browser
Browser