Infectious Disorders of Adults: Pneumonia

Study Notes

Infectious Disorders of Adults

Pneumonia: inflammation of the lung parenchyma caused by microorganisms such as bacteria, mycobacteria, and viruses.
- Community-Acquired Pneumonia (CAP): most common infectious disease that occurs in the community or within the first 48 hours of hospitalization.
  - Common Causes:
    - Streptococcus pneumoniae: most common bacterial cause, prevalent in people under 60 without comorbidity and those over 60 with comorbidity.
    - Haemophilus influenzae: frequently affects older adults and those with comorbidities like COPD, alcoholism, and diabetes.
    - Mycoplasma pneumoniae: spread by infected respiratory droplets, person-to-person contact. Can be treated for Mycoplasma antibodies.
    - Viruses: especially common in infants and children.
- Healthcare-Associated Pneumonia (HCAP): caused by MDROs (multidrug-resistant organisms) due to prior healthcare contact.
  - HCAP: difficult to treat, initial antibiotic treatment should not be delayed.
- Hospital-Acquired Pneumonia (HAP) or Nosocomial Pneumonia: develops 48 hours or more after hospitalization and was not incubating at admission.
  - HAP: associated with high mortality due to virulence of organisms, antibiotic resistance, and patient's underlying conditions.
  - Presentation: new pulmonary infiltrate on chest x-ray with signs of infection like fever, respiratory symptoms, and purulent sputum.
Tuberculosis: caused by Mycobacterium tuberculosis, spread by airborne droplets.
Ebola: a severe, often fatal viral disease spread through contact with infected animals or bodily fluids of infected people.
MERS CoV (Middle East Respiratory Syndrome Coronavirus): a viral respiratory illness that can cause severe respiratory problems.
H1N1 (Swine Flu): a strain of influenza virus that can cause respiratory illness.
Hepatitis: inflammation of the liver caused by viral or bacterial infection.
Guillain-Barré Syndrome: a rare but serious autoimmune disorder that affects the nervous system.
Sexually Transmitted Diseases (STDs): infections that are spread through sexual contact.

Inflammatory Disorders

Inflammatory Bowel Disease (IBD): chronic inflammation of the digestive tract.
- Crohn's disease: can affect any part of the digestive tract, from mouth to anus.
- Ulcerative colitis: affects only the colon.
Appendicitis: inflammation of the appendix.
Peritonitis: inflammation of the peritoneum, the membrane that lines the abdominal cavity.
Pancreatitis: inflammation of the pancreas.
Cholecystitis: inflammation of the gallbladder.
Allergy: a hypersensitivity reaction to a substance.
Lupus Erythematosus: a chronic autoimmune disease that affects skin, joints, and other organs.
Rheumatoid Arthritis: a chronic autoimmune disease that causes inflammation of the joints.
Transplant Rejection: the body’s immune system attacks a transplanted organ.