What is the most common infection of the LRT?
What are the systemic effects of pneumonia? Interference effects?
Systemic = fever, shock, and wasting
Interference = interferes with the ability of the lungs to carry our air exchange
What type of infections are most common: UTR or LTR?
What are some clinical complications of pneumonia?
- Pleural or sterile effusion into the pleural space surrounding the lungs
- Hematologic complications (anemia, disseminated intravascular coagulation, thrombocytopenia)
- Chronic complications (abnormalities in pulmonary function, decreased arterial pO2, chronic pneumonia and Bronchieatasis)
What is the general diagnosis for pneumonia?
Differentiate between pneumonia and noninfectious pulmonary infiltrate via:
- hypersensitivity drug reactions
- lymphoma, carcinoma
- vasculitis of the lung
- congestive heart failure
What is an absolute requirement in the diagnosis of pneumonia?
Thorough history and physical, travel history, avocational activities, laboratory tests, and sputum samples
Which organisms constitute typical pneumonias? Atypical pneumonias?
Typical - S. pneumoniae, S. aurerus, Enteric Gram-negative bacilli, H. influenzae, M. catarrhalis
Atypical - Legionella pneumophila, Chlamydia pneumoniae, Mycoplasma
What organism is the leading cause of pneumococcal pneumonia? (include gram stain, shape, and virulence factor)
S. pneumoniae (Gram + diplococci)
Virulence factor is the thick polysaccharide capsule
True or False
S. pneumoniae is catalase positive
Staph = +
Strep = -
What is the virulent form of S. pneumoniae?
Encapsulated form (non-encapsulated is non-virulent)
True or False
S. pneumoniae is beta hemolytic
What are the different and effective ways of diagnosing S. pneumoniae?
- Urine (Pneumococcal C polysaccharide secreted in urine
- Gram Stain
- Quellung (swelling) Reaction (anticapsular antibodies mixed with bacteria and look for greater refraction)
- Culture (inoculated on blood medium)
- Bile Solubility (streptococci autolysed with exposure to bile)
How do you treat and prevent S. pneumoniae?
Vaccine (anticapsular antibodies for 23 strains)
Azithromycin and Clarithromycin (Adult- No co-morbidity)
Penicillin or Erythromycin (if detected early)
What organisms are responsible for GNB Induced Pneumonia?
Also enterobacter, proteus, pseudomonas, klabsiella
What is the route of transmission for GNB Induced Pneumonia?
What is the most prevalent organism that causes GNB Induced Pneumonia?
True or False
Nearly all patients with GNB Induced Pneumonia have an underlying disease
What is the treatment for GNB Induced Pneumonia?
Broad spectrum antibiotics
Multidrug therapy (provides coverage before identification and prevents emergence of resistant strains)
What is the gram stain, shape, and virulence factor of Klebsiella pneumoniae?
Virulence factor is the large polysaccharide capsule
What is the distinguishable symptom of Klebsiella pneumoniae?
Sputum is red and gelatinous, almost resembling jelly
What other organism is as important as Klebsiella pneumoniae in causing Klebsiella pneumonia?
True or False
Klebsiellas are NOT normal flora
False (normal flora of the intestines)
What is the prevention and treatment of Klebsiella pneumonia?
Mycoplasma pneumonia is the leading cause of pneumonia among what groups?
What are the symptoms of Mycoplasma pneumonia?
Fever, headache, dry cough (begins later)
What feature of Mycoplasma pneumoniae makes them unique?
Lack a cell wall (so deformed with varying shapes)
True or False
M. pneumoniae require a very low dose for infection
What is ciliostasis?
Allows the LRT to become contaminated with microbes and mechanically irritated (leads to cough)
What is the transmission of Mycoplasma pneumoniae?
What is the most efficient means of diagnosing Mycoplasma pneumoniae?
PCR (good sensitivity)
Serologically (detect IgM and IgG)
What is the prevention and treatment for Mycoplasma pneumoniae?
NO antimicrobials that act against cell walls
Tertracycline and erythromycin shorten illness
What is paroxysmal coughing?
Sudden bouts of violent, uncontrollable coughing. Often forceful enough to rupture small blood vessels in the eye or brain.
Unique symptom of Pertussis
What are the three stages of Whooping Cough?
1) Catarrhal Stage (common cold)
2) Paroxysmal Stage (ciliated epithelium is sloughed and classic whooping cough begins)
3) Convalescent Stage (complications occur; pneumonia, seizures, encephalopathy)
What is the causative agent of pertussis? What is it's gram stain, shape, and features?
Bordetella pertussis (gram negative rod)
Do NOT survive well outside the host and do not tolerate drying or sunlight
Where and how does Bordetella pertussis infect?
Enters the respiratory tract and attaches and forms dense masses on ciliated cells of the epithelium (trachea, bronchi, bronchioles)
Pertussis toxin present on the surface acts as an A-B toxin
How does pertussis toxin cause disease?
Acts as an A-B toxin.
Active A protein inactivates host cell G protein, leading to maximum cAMP production. This causes massive increase in mucus output.
What are some pathogenic complications of pertussis?
Bronchioles become completely obstructed and get partial lung collapse
Paroxysmal coughing causes hemorrhages in the brain and seizures
When are pertussis patients MOST infectious?
During the runny nose period
True or False
Humans and Swine are the only reservoirs for pertussis
False (Humans ONLY)
What is the most efficient way to diagnose pertussis?
Culture (very specific; must inoculate at bedside)
What is the prevention and treatment for pertussis?
Vaccination of infants with killed B. pertussis
Acelluar vaccine (cell wall removed)
Treat with erythromycin
What is the causative agent of tuberculosis?
What is unique about Mycobacterium tuberculosis?
Grows VERY slowly
Gram + cell wall with complex glycolipids (acid fast staining, resistant to drying and disinfectants)
What is the pathogenesis of TB?
- acquired via inhalation
- after 2 weeks DTH occurs due to intense immune reaction
- macrophages surround organism and form giant cells
- lymphocytes and macrophages collect and form granulomas (TUBERCLE)
*lung cavities (discharged lung) can persist and enlarge
What is Primary Pulmonary TB?
Active disease that occurs within 2 years
Symptoms - malaise, weight loss, cough, night sweats, hemoptysis
Marked by pneumonitis or abcess formation (can lead to scar or Ghon complex formation)
What is the Mantoux test?
Injection of a small amount of purified protein derivative (PPD) derived from M. tuberculosis intradermally
Redness and swelling signifies a PAST exposure (NOT a current infection)
What is the prevention of TB?
Live-Attenuated vaccine from M. bovis (causes positive PPD test and is not safe for the immuno compromised)
Control of TB aided by use of skin tests and lung x-rays
Patient's whose PPD has changed form negative to positive are usually treated
What is the treatment of TB?
Resistance to antimicrobials is frequent
Treated with two or more antimicrobials SIMULTANEOUSLY for a minimum of 6 months (Rifampin and isoniazid is favored)
True or False
If you do not have a poor history on the patient or you know they have been exposed, you do a basic workup and treat with a single antimicrobial
You do a thorough workup and always use MULTIPLE antimicrobials for TB or suspect TB and long antimicrobial courses
What are the symptoms of Legionnaires' Disease?
Headache, muscle aches, a rapid rise in temperature, confusion, and shaking chills
What is the causative agent of Legionnaires' Disease?
Legionella pneumophila (gram negative rod)
*different strains cause differing presentations
What is unique about Legionella pneumophila's ability to survive?
Resistant to chlorine
Survives well in water systems (particularly hot water systems)
Have been found in aerosols from air conditioner cooling towers, nebulizers, and shower and water faucets
Where does Legionella pneumophila infect?
Lodges in or around the alveoli of the lung
What is the prevention/treatment of Legionella pneumophila?
Better disinfecting procedures
Treated with high doses of erythromycin concurrently with rifampin