Chapter 20 flashcards

These flashcards cover key vocabulary and concepts related to infections of the respiratory tract, including anatomical structures, various infections, and their causative agents.

Upper respiratory tract

Includes nasal passages, oral cavity, pharynx, and larynx.

Lower respiratory tract

Consists of the trachea, bronchi, and lungs.

Common Cold

Most common viral infection of the upper respiratory tract caused by more than 200 viruses, primarily rhinoviruses.

Influenza

A viral infection classified into types A, B, and C, with type A usually responsible for seasonal flu.

Streptococcal Pharyngitis (Strep throat)

An infection caused by Streptococcus pyogenes, characterized by sore throat and fever.

Croup (Laryngotracheobronchitis)

Respiratory condition in young children characterized by a barking cough caused by laryngeal swelling.

Legionellosis (Legionnaire’s Disease)

Atypical pneumonia caused by Legionella pneumophila, transmitted via contaminated water droplets.

Tuberculosis (TB)

Infection caused by Mycobacterium tuberculosis, known for its potential to become latent and reactivates as active disease.

Respiratory Syncytial Virus (RSV)

A virus primarily affecting children, causing respiratory infections and potentially leading to pneumonia.

Otitis Media

A middle ear infection that can be caused by viruses or bacteria such as Streptococcus pneumoniae.

other structures in respiratory tract

passage to the sinuses, lacrimal ducts, and inner ear

lower respiratory tract

series of diverging tubes that terminate in alveoli.

lower respiratory tract contains

trachea, right and left bronchi, bronchioles, lungs, mucociliary escalator

mucin

produced by goblet cells; helps to trap invading microbes

common cold symptoms

scratchy throat, runny/congested nose, usually self limiting

viral sinusitis

infections of upper airways spread to sinuses. mucous membranes of sinus cavities become inflamed. inflammation and congestion narrows passages - “stopped up”

bronchitis

infection of the bronchial tubes, cough that lasts more than 5 days, treatment included cough suppressants and possibly inhaled medication to reduce inflammation

pneumonia

infection involving the lungs, presentation can differ, shortness of breath and cough

RSV disease symptoms

fever, runny nose, cough (sometimes wheezing)

RSV disease

promotes the fusion of adjacent infected cells into a syncytium - a giant cell containing many nuclei.

most common cause of pneumonia in children under 1

RSV disease

Type A influenza

usually responsible for seasonal flu. can infect humans and other animals.

Type B influenza

also causes seasonal flu - less likely to be the cause of pandemic

3 proteins that confer pathogenicity

hemagglutinin (HA), neuraminidase (NA), and matrix protein (M2)

HA (influenza)

VIRAL ATTACHMENTS. A type of hemagglutinin protein that plays a critical role in the ability of the influenza virus to infect host cells by binding to sialic acid receptors.

M2 (influenza)

ESCAPE from endocytic vacuole. A viral matrix protein that facilitates the uncoating of the influenza virus within host cells, thereby enabling replication.

NA (influenza)

An enzyme that facilitates viral release by cleaving sialic acid residues, allowing the influenza virus to exit infected cells and spread to new host cells.

antigenic shift in influenza

a significant change in the antigenic properties of the influenza virus, resulting from genetic reassortment, allowing for the emergence of new viral strains that can evade the immune response.

antigenic drift in influenza

a gradual process of genetic mutation in the influenza virus that leads to small changes in its antigenic properties, resulting in variations that may affect immunity and vaccine effectiveness.

CDC and WHO - vaccines

Organizations that coordinate and promote influenza vaccination efforts globally, providing guidelines and recommendations to optimize vaccine efficacy and distribution.

in general, coronaviruses are considered a

common cold

Croup (LTB)

Infects the larynx then spreads to trachea and bronchi. Caused by Parainfluenza virus - types 1 and 2. Common in young children

symptoms of croup

fever, runny nose, and “barking cough” caused by swelling of larynx.

Otitis media

middle ear infection. caused by virus OR bacteria. diagnose by culturing fluid from the ear. often treated with antibiotics.

causes of otitis media

• Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis

• encapsulated Streptococcus pneumoniae is most common cause in children

• H. influenzae that lack capsule is becoming more common.

eustachian tube of infant vs. adult

infant = 10 degrees downward, adult = 45 degrees downward. This anatomical difference affects fluid drainage and susceptibility to infections.

sore throat

• cause could be viral or bacterial.

• infectious mononucleosis and diphtheria. usually caused by virus, but more serious bacterial infections can occur.

• may be due to GERD (gastroesophageal reflux disease) or thyroid dysfunction

sore throat symptoms

• pharyngitis: inflammation of the pharynx

• tonsilitis: inflammation of the tonsils

• laryngitis: inflammation of the larynx

• peritonsillar abscess: abscess in the pharynx

Streptococcal pharyngitis (strep throat)

cause by Streptococcus pyogenes. It is a bacterial infection characterized by a sore throat, fever, and swollen lymph nodes. Exudate on tonsils - NO COUGH.

Scarlet fever

caused by streptococcal pyogenic exotoxins. symptoms are fever and red rash, bumpy tongue (strawberry tongue). rash starts on head and neck, moves to trunk and limbs. diagnose with rapid test

streptococcal sequelae

pathological conditions that can result after a primary disease - immune response.

M protein used by S. pyogenes to attach to host cells

M protein antibodies cross-react with host cells in an autoimmune reaction. SEQUELAE

Rheumatic fever (cardiac)

is a serious inflammatory condition that can occur following untreated streptococcal throat infections (SEQUELAE). Affects heart, skin, joints, or nervous system. Pancarditis (inflammation of all layers of the heart, leading to complications such as valvular heart disease.) Erythema marginatum (distinctive rash characterized by pink rings on the trunk and limbs, often accompanied by fever and joint pain.)

Glomerulonephritis (kidney)

SEQUELAE of strep throat. Acute renal failure, hypertension, edema, proteinuria

Diphtheria (reemerging upper respiratory tract infection)

Caused by Corynebacterium diphtheriae. Symptoms: sore throat, lymphadenopathy, low-grade fever, pseudomembrane. If toxigenic, cardiac/neurological symptoms too.

DTaP series of vaccinations

Inactivated toxin given. a combination vaccine that protects against diphtheria, tetanus, and pertussis. It is recommended for children to prevent these serious diseases.

lysogenized vs. nonlysogenized

Lysogenized refers to bacteriophages that have integrated their genetic material into the host bacterium's genome, whereas nonlysogenized phages do not integrate and typically result in the lytic cycle.

Whooping cough (pertussis)

Caused by Bordetella pertussis. Disease progresses through 3 phases after incubation period: catarrhal, paroxysmal, convalescent

catarrhal

common upper respiratory infection symptoms

paroxysmal

rapidly repeating cough followed by struggling breathing “whooping”, vomiting

convalescent

patient recovers

community acquired pneumonia

caused by bacteria or viruses contracted outside of a healthcare setting, leading to lung inflammation.

when does pneumonia spike

winter months

typical vs atypical pneumonia

typical = just the lungs, atypical implies other causes as well

Pneumococcal pneumoniae (lobar pneumonia)

caused by Streptococcus pneumoniae. Humans are only natural reservoir (does not infect other animals). 91% serotypes colonize our airways; normal. Elderly + smokers are more susceptible. PMNs and fluid accumulate in the lung - cloudy look on X rays. Leads to “bands” or immature neutrophils.

Legionellosis (Legionaire’s disease)

Caused by Legionella pneumophila. Atypical: other organs affected. Symptoms are fever, systemic symptoms, shortness of breath, productive cough eventually tinged with blood. Diagnosed by culturing on buffered charcoal yeast extract agar.

less virulent version of legionellosis

pontiac fever

what do macrolides do ***

Macrolides are a class of antibiotics that inhibit bacterial protein synthesis by binding to the 50S ribosomal subunit, leading to the prevention of growth and replication of susceptible bacteria.

Tuberculosis (TB)

Caused by Mycobacterium tuberculosis - acid fast bacillus. Highly infectious even for healthy people. Some people won’t know they have it.

Latent tuberculosis infection (LTBI)

M. tuberculosis can become trapped and contained by the immune system. Person is not contagious and can’t feel it, but will have a positive TB skin test; then they should get treatment.

Pulmonary TB

Primary type. Productive cough that lasts 3 weeks, pain in chest, coughing up blood or sputum, fever, weight loss, night sweats

Miliary TB

Spreads to bloodstream. M. tuberculosis disseminates to other parts of the body and forms abscesses

TB treatment

needs many antibiotics, takes a long time. MDR (2 or more first line), XDR-TB almost untreatable.

fungal respiratory infections**

usually present with vague and seemingly unrelated symptoms.

Endemic mycoses (fungal respiratory infections)

acquired from environment, not person to person. Coccidioides species: western US. Cryptococcus neoformans: AIDS patients. Blastomyces dermatitidis: dimporphic (can exist in 2 different forms). AMPHOTERICIN B used for treatment.