Lecture 15 - Person to Person Diseases Flashcards Preview

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1

What are the different transmission modes of person-to-person diseases?

Airborne

Direct contact

Sexually transmitted

2

What are the barriers to transmission and how do pathogens overcome these barriers?

Barriers
-dessication
-oxygen intolerance

Overcoming Barriers
-Gram positive bacteria, thick cell walls prevent dessication

3

How does airborne transmission occur?

travel through airborne particulates
-cause respiratory distress
-spread by sneezin, coughing, talking

4

How does transmission through direct contact occur?

physical contact or exposure
-many human carriers, often present in low numbers in normal human microflora

compromised immune system increases risk

5

How does sexual transmission occur?

Body fluids of urogenital tract transferred during sexual activity

Difficult to track or control

Passage to newborns in infected mothers

6

What are some examples of viral and bacterial airborne diseases?

Bacterial Diseases
-Streptococcus
-Pertussis (Whooping Cough)
-Tuberculosis

Viral Diseases
-Measles
-Colds
-Influenza

7

What are the types of streptococcal diseases?

Pathogen
Streptococcus spp.
-Aerotolerant, Gram (+)

Strep Throat
-Streptococcus pyogenes
-= “Group A” Strep (GAS)

Pneumonia
-Streptococcus pneumoniae

8

What is Epidemiology+Pathogenesis of Streptococcus pyogenes?

Present in Respiratory Microflora

9

What is the Epidemiology+Pathogenesis of Streptococcus pneumoniae?

-Present in Respiratory Microflora
-Lower Respiratory Tract
-Contribute to #1 Killer Worldwide

10

What is the pathogen and epidemiology+pathogenesis of pertussis?

Pathogen
-Bordatella pertussis
-aerobic, gram (–)

Epidemiology + Pathogenesis
-High Morbidity
-adheres to upper respiratory tract

11

What is Pathogen, Epidemiology+Pathogenesis of tuberculosis?

Pathogen
Mycobacterium tuberculosis
-Gram (–), Bacillus Cells
-Highly Contagious

12

What are some other Mycobacteria pathogens?

M. leprae
-Causes Leprosy
-“Hansen’s Disease”

M. bovis
-Causes Classic TB Symptoms
-Bovine-­‐to-­‐Human Transmission
-Eradicated with Pastuerization

13

What is the pathogen and epidemiology+pathogenesis of Measles?

Pathogen
-Paramyxovirus
-Negative strand RNA Virus

Epidemiology+Pathogenesis
-Mostly affects children
-highly infectious
-Enters Nose and Throat - Systemic Viremia

14

What is the the pathogen and epidemiology of the cold?

Pathogen
-Viral - numerous types
-Primarily Rhinoviruses

Epidemiology+Pathogenesis
-most common infectious disease

15

What are the pathogen and epidemiology+pathogenesis for influenza?

Pathogen
-orthomyxovirus
-negative strand RNA virus

Epidemiology+Pathogenesis
-infects upper respiratory tract
-secondary infections

16

How can a pandemic occur?

Antigenic shifts
-major change to virus antigen due to gene reassortment
-eg. bird virus infects pig and reasortment of virus occurs. Next humans are newly infected

17

What are some examples of influenza pandemics?

Swine flu in 2009

Spanish flue in 1918

18

What are some examples of direct-contact diseases?

Bacterial Diseases
-Staphylococcal Infections
-Gastric Ulcers

Viral Disease
-Hepatitis
-Mononucleosis

19

What is the Pathogen and Epidemiology+Pathogenesis of staphylococcal infection?

Pathogen
-Staphylococcus aureus
-facultatively aerobic, Gram (+)
-microbiota of upper respiratory tract
-MRSA

Epidemiology
-Variable mortality and unknown morbidity
-healthcare associated=85%
-non-healthcare=15%

Pathogenesis
-causes several diseases

20

What are the pathogen and Epidemiology+Pathogenesis for gastric ulcers?

Pathogen
-Heliobacter pylori
-microaerophilic, Gram (–)

Epidemiology+Pathogenesis
-­But 80% of Hosts Are Asymptomatic
-May Lead to Gastric Cancer
-Attaches to Stomach and Duodenom Lining

21

What are the pathogen and the epidemiology+pathogenesis for hepatitis?

Pathogen
-numerous viruses, Hep A, B, C
-some bacteria

Epidemiology
-large decline due to vaccine

Pathogenesis
-bloodborne
-consuming shellfish

22

What are the pathogen and the epidemiology+pathogenesis for mononucleosis?

Pathogen
-Epstein-Barr Viruses, EBV
-dsDNA virus, member of herpes viral family

Epidemiology
-exteremely low mortality
-over 90% worldwide morbidity

Pathogenesis
-infects salivary gland cells and B cells

23

What are the sexually transmitted diseases?

Bacterial Diseases
-gonorrhea vs syphilis
-chlamydia

Viral Diseases
-herpes
-AIDS

24

What is gonorrhea and syphilis?

Two common and treatable STDs
-penicillin
-higher incidence of gonorrhea

25

Why is there a higher incidence of gonorrhea?

1) Strain-Specific Aquired Immunity
-Repeated Reinfection Can Occur

2) Use of Oral Contraceptives
-Disrupt Vaginal Microflora

3) Mild Symptoms in Infected Women
-­Many unaware of the disease

26

What are the Symptoms and the epidemiology for chlamydia?

Pathogen
-Chlamydia trachomatis
-obligate intracellular bacterium

Epidemiology
-most commonly reported STD in US

27

What is herpes?

Pathogen
-herpesviruses
-diverse, dsDNA virus group
-Herpes simplex I=cold sores
-Herpes simplex II=genital sores

28

What are the Pathogen and the Epidemiology+Pathogenesis for AIDS?

Pathogen
-Human Immunodeficiency Virus
-Retrovirus

Epidemiology
-recognized in 1981

Pathogenesis
-Virus targets T cells and Macrophages using gp120 protein
-viral replication=immune cell death
-syncitia = fused Healthy +
Infected Host Cells which accelerates infection/destruction of host cells

29

What is the Symptoms+Diagnosis for Streptococcus Pyrogenes?

Symptoms+Diagnosis
-Severe Sore Throat, Mild Fever
-Untreated, Leads to Scarlet Fever
-Immunofluorescence, ELISA, Throat Cultures

30

What is the Treatment + Prevention for Streptococcus Pyrogenes?

Treatment + Prevention
-No Vaccine Available
-Antibiotics
-Pencillin G, Erythromycin
-Early Diagnosis and Treatment