Human-Microbe Interaction & Epidemiology

Human-Microbe Interaction & Epidemiology

• Pathology: The study of disease.

• Infection: Does not necessarily mean damage to the host.

• Disease: Occurs when an infection causes damage.

• Pathogen: The organism that causes the infection.

• Symptoms:

  • Cannot be measured.

  • Examples: Nausea, headache, etc.

• Sign:

  • Quantifiable and observable change.

  • Examples: Temperature, lesion size.

• Syndrome: a specific group of signs and symptoms that always accompany a particular disease

Classifications of Disease

Based on they Behave within a Host and a given Population

• communicable disease - infected person can transmit the infectious agents into another person directly or indirectly

• Contagious disease - disease that are very communicable and are capable to spread easily and rapidly from one person to another

• Non-Communicable disease - unable to spread from one individual to the next

Based on Severity and Duration

• Acute - disease develops more rapidly but last a short time

• Chronic - disease that develops more slowly, body reaction may be less severe, but the next disease is likely to continue for long periods

• Subacute - disease that is intermediate between acute and chronic

• Latent - disease where the causative agents remain inactive for a time but then becomes active to produce symptoms of the disease

  • ex. shingles

Non-Communicable Diseases & Epidemiology

• Non-communicable diseases can affect immunocompromised individuals, caused by normal flora.

• Epidemiology: The study of incidence, distribution, and possible control of diseases.

Disease Patterns

• Incidence

  • the number of people in a population that contract a disease during a particular period. only account new cases at a particular time period

• Prevalence

  • The fraction of the population having the disease at specfied time

• Sporadic Disease:

  • No pattern.

  • Example: Typhoid fever.

• Endemic Disease:

  • constantly present in a population

    • Example: Common cold.

• Epidemic Disease:

  • Many people in a given area acquire certain disease in relatively short time

    • Example: Influenza.

• Pandemic Disease:

  • worldwide epidemic

    • Example: COVID-19.