1. Chapter 22 Respiratory system infections
Medgar Evers College
Biology 261
Prof. Santos

2. Anatomy and physiology of the respiratory system
Upper respiratory system includes the moist lining of the eyes (conjunctiva), nasolacrimal duct, middle ears, sinuses, mastoid air cells, nose, and throat.
Functions include temperature and humidity regulation and removal of microorganisms.

4. Lower respiratory system includes the trachea, bronchi, bronchioles, and the lungs.
The alveoli are the air sacs located in the lungs where gas exchange occurs.
Pleural membranes cover the lungs and line the chest cavity.
Ciliated cells line the respiratory tract and filter and remove germs by constantly propelling mucus out of the respiratory system.

5. Microbiota of the respiratory system
A wide variety of microorganism colonize parts of the upper respiratory system, including S. aureus.
Viruses and microorganisms are normally absent from the lower respiratory system.

6. Infections of the upper respiratory system
1- strep throat * bacterial
2- diphtheria * bacterial
3- pink eye, earache, sinus infection
* Bacterial and viral
4- the common cold * viral
5- adenoviral pharyngitis * viral

7. Infections of the lower respiratory system
Bacterial infections include
Pneumococcal pneumonia
Klebsiella pneunomia
Mycoplasmal pneumonia
Whooping cough (pertussis)
Tuberculosis
Legionnaire’s disease

8. Viral infections of the lower respiratory system
Influenza
Respiratory syncytial viral infection
Hantavirus pulmonary syndrome

9. Fungal infections of the Respiratory system
Histoplasmosis (Spelunker’s disease)
Coccidiodomycosis (Valley fever)

10. Viral infections of upper respiratory system
disease
cause
Incubation period
symptoms
Pathogenesis/epidemiology
treatment
Common cold
rhinovirus
1 to 2 days
Scratchy throat, nasal discharge, malaise, headache, and a mild cough
Viruses attach to the respiratory epithelium, inhalation of infected droplets containing the virus
No general accepted treatment, bed rest, hand washing, cold medication to alleviate symptoms

11. disease cause Incubation period symptoms Pathogenesis/epidemiology
treatment
Adenoviral pharyngitis
Adenovirus (more than 45 types)
5 to 10 days
Fever, sore throat, severe cough, swollen lymph nodes, pus on tonsils, sometimes pink eye
Viral replication in host cells, inhalation of infected droplets
No treatment just medication to alleviate symptoms

12. Bacterial infections of upper respiratory system
disease
cause
Incubation period
symptoms
Pathogenesis/epidemiology
treatment
Strep throat
S. pyogenes
2 to 5 days
Sore and red throat, with pus and hemorrhages, enlarged and tender lymph nodes
Includes c5a peptidase, hyluronic acid capsule, M protein, protein F, Protein G, exotoxins, streptolysins O and S, tissue degrading enzymes
10 days of penicillin or erthromycin
Diphtheria
Corynebacterium diphtheriae
2 to 6 days
Sore throat, fever fatigue, paralysis and heart and kidney failure
Exotoxins released and absorbed by bloodstream
Antitoxin and erythromycin to prevent transmission

13. Very little invasive ability by pathogen.
Formation of pseudomembrane on tonsils from the result of dead epithelial cells, leukocytes, and fibrin. This membrane may loosen up and cause suffocation.

14. Post streptococcal complications
1- acute rheumatic fever
2- acute post streptococcal glomerulonephritis

15. Acute rheumatic fever Inflammatory disease
Develops as a complication to Strep infections.
Usually affects children 5 to 15 years old
Can cause permanent damage to heart and valves
Rare in the U.S.A

16. Symptoms of rheumatic fever
Painful and tender joints — most often the ankles, knees, elbows or wrists; less often the shoulders, hips, hands and feet
Pain in one joint that migrates to another joint
Red, hot or swollen joints
Small, painless nodules beneath the skin
Chest pain
Sensation of rapid, fluttering or pounding heartbeats (palpitations)
Fatigue
Shortness of breath

17. acute post streptococcal glomerulonephritis
Post-streptococcal glomerulonephritis. Glomerulonephritis may develop a week or two after recovery from a strep throat infection. An overproduction of antibodies stimulated by the infection may eventually settle in the glomeruli, causing inflammation.

18. acute post streptococcal glomerulonephritis symptoms
Symptoms usually include swelling, reduced urine output and blood in the urine. Children are more likely to develop post-streptococcal glomerulonephritis than are adults, and they're also more likely to recover quickly.

19. disease cause Incubation period symptoms Pathogenesis/epidemiology
treatment
Conjunctivitis otitis media and sinus infections
Most common pathogens for all three all Haemophilus influenzae and Streptococcus pneumoniae
Red swollen eyes, pus discharge, earache, pain and pressure in the sinus area
antibiotics

20. Viral infections of lower respiratory system
disease
cause
Incubation period
symptoms
pathogenesis
treatment
Influenza
Influenza A virus, an orthomyxovirus
1 to 2 days
Fever, muscle ache, lack of energy, headache, sore throat, nasal congestion, cough
Antigenic drift and shift allow for variations, virus infects respiratory epithelium and destroys the cells
Vaccine is 80 to 90 % effective, drugs such as amantadine and rimantadine are effective against type A

21. Influenza Influenza A has 8 segments of ss RNA, has an envelope.
The envelope has 2 types of spikes; HA and NA
HA hemagglutinin
NA neuraminidase antigen

22. HA allows the virus to attach
NA allows virus to be released
There are subtypes of HA (16) and NA (9). For example; H1, H2, N1, and N2.
Swine flu 2009 H1N1
Avian flu 1997 H5N1
* H1, H2, H3, N1 and N2 spread among us!

23. Antigenic drift- minor mutations in the genes that encode for HA and NA. this is responsible for the yearly outbreaks of influenza called seasonal influenza.
A/Texas/77 (H3N2) vs A/Bangkok/79 (H3N2)

24. Antigenic shift- a sudden major change in the spike proteins because the virus has acquired new genome.
Antigenic shift is the cause of pandemic influenza

26. disease cause Incubation period symptoms pathogenesis treatment
Respiratory syncytial viral infection
RSV, a paramyxo-virus
1 to 4 days
Runny nose, cough, fever, wheezing, difficulty breathing, dusky color due to lack of oxygen
Inhaling infected droplets, virus enters the respiratory tract and causes death and sloughing of the cells
No vaccine available, no effective anti viral medication exist!

27. disease cause Incubation period symptoms pathogenesis treatment
Hanta virus pulmonary syndrome
Sin Nombre and other hantaviruses of the bunyavirus family
3 days to 6 weeks
Fever, muscle ache, vomiting, diarrhea, cough, shortness of breath
Viral antigen localizes in the capillary walls in the lungs.
No proven anti viral treatment
Good hygiene, good ventilation, avoid contact with rodents

28. Bacterial infections of the lower respiratory system
disease
cause
Incubation period
symptoms
pathogenesis
treatment
Pneumococcal pneumonia
Streptococcus pneumoniae
1 to 3 days
Cough, fever, shaking chills, rust color sputum from degraded blood, shortness of breath, chest pains
Inhalation of virus into the alveoli, rapid multiplication, inflammatory response, and pain due to nerve ending involvement
Penicillin, erythromycin, and others as prescribed by your doctor

29. disease cause Incubation period symptoms pathogenesis treatment
Klebsiella pneumonia
Klebsiella pneumoniae
1 to 3 days
Chills, fever, chest pain, gross bloody sputum
Aspiration of colonized droplets from the throat, destruction of lung tissue.
A member of the cephalosporin antibiotics with an aminoglycoside.

30. disease cause Incubation period symptoms pathogenesis treatment
Mycoplasmal pneumonia
Mycoplasma pneumoniae
2 to 3 weeks
Gradual cough, fever, sputum production, headache, fatigue, muscle ache
Cells attach to specific receptors on the respiratory tract inhibiting cilia motion and destruction of ciliated cells
Tetracycline and erythromycin

31. Some key differences
1- pain associated mostly with pneumococcal pneumonia due to involvement of nerve endings 2- klebsiella pneumonia involves bloody and gelatin-like sputum and involves rapid destruction of lung tissue and lung abscess formation. Mycoplasmal pneumonia is resistant to penicillin due to the fact that the pathogen has no cell wall.

32. disease cause Incubation period symptoms pathogenesis treatment
Whooping cough
(pertussis)
Bordella pertussis
7 to 21 days
Runny nose, spasms of violent cough, vomiting and possible convulsions
Toxins secreted by pathogen destroys epithelial cells
Vaccination and erythromycin if given early is effective.

33. Some facts Disease has three stages
1- catarrhal- inflammation of mucous membrane
2- paroxysmal- violent cough followed by forceful attempts to inhale
3- convalescent- period of recovery

34. disease cause Incubation period symptoms pathogenesis treatment
Tuberculosis
Mycobacterium tuberculosis * cell wall has lots of lipids
2 to 10 weeks
Chronic fever, weight loss, cough, sputum production
2 or 3 medications given together for a long period of time such as Isoniazid and rifampin.

35. Pathogenesis
1- pathogen enters the lungs 2- alveolar macrophages ingest the pathogen 3- the pathogen survives inside the macrophage 4- additional macrophages and lymphocytes are recruited to the site. 5- foamy macrophages are formed.

36. 6- fibrous capsule surrounds macrophages =tubercle 7- some infected macrophages die releasing the pathogen into airway 8- within the tubercle T cells secrete cytokines that trigger macrophages to destroy the pathogen.

38. disease cause Incubation period symptoms pathogenesis treatment
Legionnaires’ disease
Legionella pneumophila
2 to 10 days
Muscle ache, headache, fever, cough, shortness of breath, chest and abdominal pain
Warm water contaminated with pathogen, pathogen multiplies within the phagosome, destroys cell and then inflammation follows.
Rifampin and erythromycin

39. Fungal infections of the Lungs
disease
cause
Incubation period
symptoms
pathogenesis
treatment
Valley fever
*Only in semi arid regions of the western hemisphere.
Coccidioides immitis
2 to 3 weeks
Fever, cough, chest pain, loss of appetite, pain in joints,
Spores form in the lungs, inflammatory response to damage, inhalation of airborne pathogen spores.
Antimicrobial medications such as
Amphotericin B, and fluconazole.

40. disease cause Incubation period symptoms pathogenesis treatment
Spelunker’s disease
Histoplasma capsulatum
5 to 8 days
Slight fever, chest pain, cough and chronic sores in mouth
Inhalation of spores, they change to yeast, forming granulomas
Amphotericin B, itraconazole for serious infections.

41. Virulence factors of Streptococcus pyogenes.
Includes
C5a peptidase destroys the C5a complement component
Hyluronic acid capsule helps the bacteria attach to the epithelial cells
M protein helps destroy the C3b Complement component preventing opsonization
Protein F helps the bacteria attach to host
Protein G is an Fc binding receptor
Exotoxins responsible for scarlet fever, toxic shock and flesh eating fasciitis
Streptolysins O and S lyse wbc’s and rbc’s.
Tissue degrading enzymes helps pathogen spread by destroying DNA, Proteins, blood clots.