5.1 Diseases

Communicable Diseases

  • Illnesses that spread from person to person, or animal to person.
  • Caused by pathogens (bacteria, viruses, fungi, protozoa).

Communicable Diseases: Examples

Disease Causative Agent Symptoms Prevention
Influenza Virus Fever, cough, sore throat, muscle aches Vaccination, hand washing
Measles Virus Fever, rash, cough, runny nose, red/watery eyes Vaccination
Malaria Protozoan Fever, chills, sweating, headache, muscle aches Mosquito nets, antimalarial drugs, mosquito control
Dengue Virus Fever, headache, rash, muscle/joint pains Mosquito control
Chikungunya Virus Fever, joint pain, headache, muscle pain, joint swelling, rash Mosquito control
HIV Virus Weakened immune system, opportunistic infections Condoms, avoid infected blood, PrEP

Vector

  • Meaning: An organism that transmits a disease from one animal/plant to another.
  • Many are bloodsucking insects.
  • Common Vectors and Diseases:
    • Mosquitoes: Malaria, Dengue fever, West Nile virus, Zika virus.
    • Ticks: Lyme disease, Rocky Mountain spotted fever.
    • Fleas: Plague.
    • Flies: Pink eye, salmonellosis (mechanical transmission).

Preventing Diseases: Multi-faceted Approach

  • Personal Hygiene: Frequent handwashing, covering coughs/sneezes, safe food handling, avoiding sharing personal items, staying home when sick.
  • Vector Control: Eliminating breeding grounds (stagnant water), reducing contact (screens, nets), chemical control (insecticides), biological control (natural predators).
  • Vaccination: Administration of vaccine to develop protection.
  • Immunization: Process of becoming immune/resistant to infectious disease (via vaccine).

Harmful Effects of Substances

  • Consuming Tobacco: Increased risk of cancer, heart disease, stroke, COPD.
  • Drinking Alcohol: Increased risk of liver disease, cancer, heart disease, addiction.
  • Taking Drugs: Increased risk of addiction, overdose, death, various health problems.