1. I NTRODUCTION TO I NFECTIONS

2. I NFECTION Invasion and multiplication of microorganisms in body tissues, especially that causing local cellular injury due to competitive metabolism, toxins, intracellular replication, or antigen-antibody response

3. Overview of Plasmodium's life cycle

4. D IFFERENT TYPES OF INFECTIONS Airborne infection: one that is contracted by inhalation of microorganisms or spores suspended in air on water droplets or dust particles. Droplet infection: infection due to inhalation of respiratory pathogens suspended on liquid particles exhaled by someone already infected.

5. D IFFERENT TYPES OF INFECTIONS Endogenous infection: that due to reactivation of organisms present in a dormant focus, as occurs in tuberculosis. Opportunistic infection: infection by an organism that does not ordinarily cause disease but becomes pathogenic under certain circumstances (e.g., impaired immune responses).

6. A IRBORNE I NFECTION

7. R ESPIRATORY TRACT INFECTION Infection involving the respiratory tracts Classified as an upper respiratory tract or a lower respiratory tract infection Lower respiratory infections, such as pneumonia, tend to be far more serious conditions than upper respiratory infections, such as the common cold.

9. URTI Infections in the nose, sinuses, pharynx, and larynx Typical infections of the upper respiratory tract include: Tonsillitis Pharyngitis Sinusitis Otitis media Influenza Common cold

10. S YMPTOMS OF URTI S Cough Sore throat Runny nose Nasal congestion Headache Low grade fever Sneezing

11. LRTI Lower respiratory tract infections are generally more serious than upper respiratory infections LRIs are the leading cause of death among all infectious diseases The two most common LRIs: Bronchitis and pneumonia

12. P NEUMONIA Pneumonia is an inflammatory condition of the lung Especially affecting the microscopic air sacs (alveoli) Associated with fever, chest symptoms, and a lack of air space (consolidation) on a chest X-ray

13. C AUSES Microbial infections: Bacteria, Viruses Fungi Parasites Other causes

14. T YPICAL SYMPTOMS Cough Chest pain Fever Difficulty breathing

15. D IAGNOSIS X-rays Sputum examination

17. C LASSIFICATION Community-acquired Aspiration Hospital-acquired Ventilator-associated pneumonia

18. C AUSATIVE AGENTS Viruses and bacteria (most common) Fungi and parasites (less common) Mixed infections with both viruses and bacteria: Up to 45% of infections in children 15% of infections in adults Causative agent is not isolated in approximately half of cases

19. I NFLUENZA Influenza affects both the upper and lower respiratory tracts More dangerous strains such as H5N1 tend to bind to receptors deep in the lungs

20. M ANAGEMENT Antibiotics Antiviral