8 - Infectious Diseases Flashcards
How are most skin infections initiated?
Mechanical injury of the epidermis
How are most gastrointestinal pathogens transmitted?
Fecal-oral route via contaminated food or drink
What is the body’s principal method of defending against fecal-orally transmitted infections?
Acidic gastric secretions, pancreatic enzymes, and bile detergents
What do both the skin and gut epithelial cells produce to protect against infectious disease?
IgA antibodies
How are most infections transmitted from person to person (3)?
Respiratory, fecal-oral, or sexual routes
How can infectious diseases escape from antibody-mediated host defenses?
Antigenic variation
What is the ultimate means by which infectious diseases can avoid the immune system?
Latent infection in which few if any viral genes are expressed
What is it called when viral agents have a predilection for certain types of cell to infect?
Tropism
What bacterial surface proteins bind bacteria to host cells or ECM?
Adhesins
How does tuberculosis utilize the immune system in its replication?
M. tuberculosis activates the alternative complement pathway, resulting in opsonization with C3b. Once coated with C3b, M. tuberculosis binds to the CR3 complement receptor on macrophages, enters the macrophages, and replicates within phagosomes
Describe bacterial endotoxin.
A lipopolysaccharide (LPS) in the outer membrane of Gram-negative bacteria that both stimulates host immune responses and injures the host
Describe bacterial exotoxins.
Secreted bacterial proteins that cause cellular injury and disease.
What are some examples of bacterial exotoxins?
Enzymes, toxins altering intracellular signaling, neurotoxins, superantigens
What are some types of inflammatory response to infectious disease?
Suppurative, granulomatous, cytopathic-cytoproliferative reactions, tissue necrosis, scarring
How are most infectious diseases diagnosed?
Cultures, biochemical or serologic identification, and molecular diagnosis
What stain can identify most bacteria?
Gram stain
What stain can identify mycobacteria and nocardiae?
Acid-fast stain
What stain can identify fungi, legionella, and pneumocystis?
Silver stain
What stain can identify fungi and amebae?
Periodic acid-Shiff stain
What three techniques can identify all classes of infectious agents?
Antibody stains, culture, DNA probes
What are four examples of respiratory viruses with acute (transient) presentation?
Adenovirus, rhinovirus, influenza, and respiratory syncytial virus
What are four examples of digestive viruses with acute (transient) presentation?
Mumps, Rotavirus, Norovirus, and Hepatitis A-E
What are four examples of systemic viruses with acute (transient) presentation and skin eruptions?
Measles, Rubella, Varicella-zoster, HHSV 1-2
What are three examples of systemic viruses with acute (transient) presentation and hematopoietic disorders?
CMV, EBV, and HIV-1-2
What are two examples of arboviral- and hemorrhagic fever-related viruses with acute (transient) presentation?
Dengue and Yellow fever
What is an example of a viruse with acute (transient) presentation of the skin /genital warts?
HPV
What are two examples of CNS viruses with acute (transient) presentation?
Poliovirus and JC virus
What is a rare, late complication of measles?
Encephalitis
Describe mumps (type and presentation).
Acute systemic viral infection; pain and swelling of the salivary glands
Is there more than one type of mumps?
Yes: mumps parotitis, orchitis, and encephalitis
Describe poliovirus (transmission, type, presentation).
Fecal-oral; a spherical, unencapsulated RNA virus; anterior horn destruction and paralysis of limb and diaphragm
What is latency as it refers to viral genomes?
The persistence of viral genomes in cells that do not produce infectious virus
What effects can the superantigens in Staphylococcus aureus and Streptococcus pyogenes cause?
Toxic shock syndrome and food poisoning
What disease does Streptococcus pyogenes cause (respiratory)?
Pharyngitis
What disease does Corynebacterium diphtheria cause (respiratory)?
Diphtheria
What disease does Bordetella pertussis cause (respiratory)?
Pertussis
What disease does Streptococcus pneumonia cause (respiratory)?
Lobar pneumonia
What disease does Mycobacterium tuberculosis cause (respiratory)?
Tuberculosis
What disease does Legionella pneumophila cause (respiratory)?
Legionnaire disease
What disease does Helicobacter pylori cause (gastrointestinal)?
Peptic ulcers