Respiratory system diseases

Infectious Disease 

Etiological Agent 

( Name of microorganism ) 

Morphology ( if needed) 

Port of Entry/Mode of transmission

Characteristic Symptom 

Prevention 

Pharyngitis

Streptococcus pyogenes

(causes beta hemolysis)

G(+) cocci

Upper respiratory tract, droplet

Redness and patches in the throat, edema, lymph node enlargement

Malaise, headache

Isolation

Proper sanitization

Timely treatment is best to avoid complications 

Diphtheria

C. diphtheriae

G(+) rod

Upper respiratory tract, droplet

Similar to strep throat, lymph node enlargement

Tough grayish leathery patch

DTap vaccine (Diphtheria, tetanus, pertussis) 

Pertussis (Whooping cough)

B. pertussis

Upper respiratory tract, droplet

Extensive cough with a gasp of air at the end (characteristic sound known as whoop)

Increased mucus secretion (Due to AB toxin)

DTap vaccine

Tuberculosis

Mycobacterium tuberculosis

Acid fast + (pink)

Lower respiratory tract, airborne

Cough, chest discomfort, lung lesions (Lung lesions are called tubercles)

Complication: Become systemic affecting other parts of the body such as bones, intestines, and reproductive system

Isolation, vaccines available but less commonly used in areas without tuberculosis

(Typical) Pneumonia 

Streptococcus pneumoniae

Lower respiratory tract, endogenous infection

Fluid buildup in lungs (alveoli)

High fever, breathing difficulties, cough, chest pain

Timely treatment of other respiratory infections

Legionellosis (Atypical Pneumonia)

L. pneumophila

Lower respiratory tract, it  is spread through aerosols of contaminated water (Not person to person)

Fluid accumulation in lungs

Chest discomfort, difficulty breathing (same as pneumonia)

Proper water treatment in high risk places especially hospitals and hotels

Influenza

Influenzae virus

Lower respiratory tract, droplet

Cold, fever, body aches, cough, fatigue

Washing hands, wear a mask

Flu vaccine (every year because of drift!)