Factors and Reservoirs of Disease Spread

Study Notes

Virulence of pathogen: The severity of the disease caused by the pathogen.
Susceptibility of the population: How easily the population can be infected by the pathogen.
Lack of immunization: The absence of vaccines to protect against the disease.
Inadequate sanitation procedures: Poor hygiene and sanitation practices can increase the risk of transmission.
Mode of transmission of the pathogen: How the pathogen spreads from one person to another.

Any place where a pathogen can survive or reproduce until it is transferred to a host
Human reservoir: The primary source of infection for many human pathogens since they are often species-specific. Carriers are individuals who harbor the pathogen but do not exhibit signs or symptoms.
- Incubatory carrier: Transmits the pathogen during the incubation period..
- Convalescent carrier: Transmits the pathogen during recovery from the disease.
- Active carrier: Has recovered from the disease but continues to harbor the pathogen.
- Passive carrier: Carries the pathogen without having experienced the disease.
Animal reservoir: Animals are often sources of infection for humans.
- Zoonoses: Infectious diseases that humans acquire from animals.
- Routes of transmission from animals:
  - Direct contact with infected animals or their waste.
  - Inhalation of contaminated hides, fur, or feathers.
  - Ingestion of contaminated food or water.
  - Injection of the pathogen via insect vectors.
Inanimate reservoir: Examples include air, soil, food, milk, water, and fomites.
- Fomites: Contaminated materials such as clothing, bedding, utensils, etc..
- Air: Can be contaminated by dust, smoke, and respiratory secretions expelled from humans.

Contact transmission: Spreading of a disease agent through direct, indirect, or droplet transmission.
- Direct contact transmission: Person-to-person transmission through physical contact (e.g., touching, kissing, sexual intercourse).
- Indirect contact transmission: Transmission through a non-living object (e.g., touching a contaminated surface).
- Droplet transmission: Spread via droplet nuclei that travels short distances (usually less than 1 meter).
Vehicle transmission: Transmission through a contaminated medium such as food, water, or blood.
Vector transmission: Transmission through an animal that carries the pathogen from one host to another.

Report cases of communicable diseases: Early reporting allows for prompt public health interventions.
Public health education: Raising awareness about disease transmission and prevention methods.
Identification and elimination of reservoirs of infection: Target the sources of the pathogen to reduce transmission.
Isolation of diseased individuals: Preventing further spread by separating infected individuals.
Participation in immunization programs: Vaccination is a critical component of disease prevention.
Treat sick individuals: Medical management can help reduce disease severity and transmission.