Chapter 24 Respiratory system infections

Upper respiratory infection

Nose,

pharynx (throat),

middle ear,

sinuses

microflora- many potentially pathogenic; suppressed by other microbes

Lower respiratory system

Larynx (voice box)

Trachea (windpipe

Lungs (bronchial tubes, alveoli [sacs where oxygen and CO2 are exchanged])

Pleura- double membrane around lung

Mostly sterile

Itis=Inflammation

Pharyngitis- inflammation of throat, sore throat

Laryngitis- inflammation of larynx, affects speaking

Tonsillitis- inflammation of tonsils

Sinusitis- inflammation of sinuses

Strep throat

Upper respiratory

Streptococcus pyogenes

• Group A (gas)

Resistant to phagocytosis

Virulence factors:

• Streptokinases- lyse fibrin clots

• Streptolysins- kill tissue, leukocytes, RBCs

Symptoms:

• Painful sore throat, fever, white patches

Transmitted

• Droplets, through the air

Diagnosis

• Rapid tests for bacteria

Treatment:

• Antibiotics

Diphtheria

Upper respiratory

Corynebacterium diphtheriae

Pleomorphic

Symptoms;

• Sore throat, fever, swelling of neck

Transmission;

• Droplet respiratory

Grayish membrane in throat

Some infected with Phage produce toxin- inhibits protein

Cutaneous diphtheria

• through cuts

• gray membrane

• more common

• contact with opening

Vaccine-DTaP

Diagnosis: selective and differential medias

Treatment:

• Antibiotics and antitoxins

Clubbed shaped

Otitis

Middle ear infection (upper respiratory infection)

Infection behind ear drum

Fluid becomes trapped following an illness

Kids are more prone

Three most common causes:

• Streptococcus pneumoniae

• Haemophilus Influenzae

• Streptococcus pyogenes

Treatment: Antibiotic

Common Cold

Upper respiratory

Rhinoviruses (most common)

• Single viruses can cause the cold

Coronaviruses

Symptoms:

• Sneezing, nasal secretion, congestion

• Usually no fever

• UR, ear, sinuses, lungs

Transmission:

• Droplet, respiratory

Treatment: Supportive care, run its course

Whooping cough

Bordatella pertussis

Upper respiratory infection

Capsule

Transmission:

• Respiratory, droplets

Makes toxins

• Tracheal cytotoxin- on cell wall, damage ciliated cells

• Pertussis toxin- blood stream; systemic symptoms

Symptoms:

• Catarrhal stage- First, Ressembles common cold, runny nose, sneezing

• Paroxysmal stage-Second, prolong coughing, mucus accumulates

  • 1-6 weeks

• Convalescence stage- recovery, can take up to months

Vaccine- DTaP (P-pertussis)

Diagnosis

• Clinicla symptoms

Treatment:

• Antibiotics

RSV

Respiratory syncytial virus=RSV

Common in babys= 2-6 months

Cold like symptoms

Diagnosis

• Serological test, rapid

Immune globulin for infants with lung problems

Treatment:

• Supportive Care

Histoplasmosis

Histoplasma capsulatum

Lower respiratory infection

• dimorphic fungus (yeast like in tissue, filamentous in soil)

Resembles TB

Infects lungs (not severe other than in immunocompromised)

Reservoirs:

• Airborne, bird droppings

Treatment:

• Antifungals

Tuberculosis

Mycobacterium tuberculosis

• Acid-fast bacteria

Healthy hosts can kill or control

Transmitted:

• coughing, droplets, Inhale, through the air

If infection continues, pathogens are isolated in a tubercle (“lump”)

Symptoms:

• coughing and coughing up blood

Diagnosis: Skin test (Type 4 hypersensitivity reaction)

Treatment:

• Antibiotics (up to 6 months minimum)

Vaccine

9 million cases per year

2 million death from them

• 1/3 world’s population infected

Pneumonia

Streptococcus pneumoniae (most common)

Aka: typical pneumonia or pneumococcal pneumonia

alpha hemolytic

Capsule

Symptoms: Hugh fever, breathing difficulty, chest pain, coughing

Fluid build up

Sputum rust colored

Older pateints often develop as secondary infection

Treatment:

• Antibiotics

Vaccine

Other causes:

• Haemophilus influenzae

• Mycoplasma pneumoniae (“walking pneumonia”

• Legionella pneumophila (in water)

Pneumocystis pneumonia

Pneumocystis jirovecii

• Fungus (or protozoan)

• mainly immunosupressed pateints

Indicator of aids

Forms cyst in lungs

Treatment:

• Antibiotics

Flu

Influenzavirus: (orthomyxoviridae)

Symptoms:

• chills, fever, headache, aches

Gram negative

RNA segments, envelope (spikes)

Hemagglutinin 17- allows for attachment and entry

Neuraminidase 10- allows for virus to get out of host cell

Antigenic drift: mutations

Antigenic shift- 2 flu strains affect one host, new strand of virus (mixed) more worse

Treatment

• Supportive care or antivirals

• Neuraminidase inhibitors

Vaccine