Infectious disease 🦠

• INFECTIOUS DISEASE

  • caused by pathogens
  • eg: influenza, HIV
• Infectious disease spread through:

  • droplets in Air when person cough or sneeze
  • direct contact with infected( exchange of body fluids)
  • contaminated food and water
• INFLUENZA VIRUS

  • attacks respiratory system
  • transmitted by :respiratory droplets from infected/ touching contaminated surfaces
  • Symptoms: high fever, headache, cough, sore throat
• PNEUMOCOCCAL DISEASE

  • caused by pneumococcal bacteria
  • attack different parts of body and lead to infection of lung, blood, brain and spinal cord
  • Transmitted by: respiratory droplets of infected/ contaminated surfaces
  • symptoms: fever, headache, cough, chest pain, rapid breathing
• prevention of bacteria and virus

  1. avoid close contact with infected
  2. cover mouth and nose when sneeze or cough
  3. wash hands with disinfectant
  4. avoid touching eyes, mouth and nose
• Prevention of influenza

  • Influenza vaccination
  • take prescribed antiviral drugs
• Prevention of pneumococcal disease

  • pneumococcal vaccination
  • take prescribed antibiotics
• Vaccines contain an agent that resembles a pathogen and prevents infectious diseases by stimulating white blood cells to quickly produce antibodies when a pathogen invades
• Characteristics of antibodies

  1. produced by white blood cells
  2. proteins
  3. can only destroy specific type of pathogen
• how vaccines work

  1. agent resembling pathogen introduced to body in form of a vaccine
  2. white blood cells detect the agent and binds to the antigen present on the surface
  3. white blood cells are stimulated to divide
  4. antibodies produced by white blood cell destroy pathogen in vaccine
• Antibiotics used to treat bacterial infections by preventing synthesis of cellular structures.
• Misuse and overuse of antibiotics accelerate the emergence of antibiotic-resistance bacteria
• 1. In population of bacterial cells, some are more sensitive to antibiotic while others are less sensitive
  2. when antibiotic taken, more sensitive bacterial cells killed, less sensitive are not easily killed and may survive
  3. course completed —-> higher chance all bacterial cells killed
  4. course not complete —-> less sensitive bacterial cells will multiply and increase in numbers
• Antibiotics target bacteria by preventing synthesis of cellular structures
• Antibiotics are ineffective against virus’s because viruses do not have cell walls, cell membranes or ribosomes
• What is the difference between infectious and non-infectious diseases?

  Infectious diseases can be spread from person to person, while non-infectious diseases cannot.
• Give an example of an infectious disease.

  Influenza
• Give an example of a non-infectious disease.

  Diabetes
• What is a pathogen?

  A pathogen is a microorganism that causes a disease.
• How do infectious diseases spread?

  Infectious diseases spread through droplets in the air, direct contact, and contaminated food and water.
• What are the signs and symptoms of influenza?

  High fever, headache, stuffy nose, cough, sore throat, and muscle aches.
• What causes pneumococcal disease?

  Pneumococcus bacteria (Streptococcus pneumoniae).
• How is influenza transmitted?

  Through respiratory droplets and touching contaminated surfaces.
• What are the signs and symptoms of pneumococcal disease?

  Fever, headache, vomiting, cough, chest pain, and rapid breathing.
• What are the similarities in the transmission methods of influenza and pneumococcus?

  1. Droplet infection containing the virus/bacteria

  2. Touching contaminated objects or surfaces and then touching mouth, nose, or eyes

  
• How can the transmission of influenza virus and pneumococcus be reduced?

  • Avoid close contact with infected individuals
  • Cover mouth and nose when sneezing or wear a mask
  • Wash hands with soap and water or use disinfectant
  • Avoid touching eyes, nose, and mouth
  • Vaccination for influenza and pneumococcus
  • Take prescribed antiviral drugs and antibiotics

  
• How do vaccines work?

  Vaccines stimulate white blood cells to produce antibodies against pathogens.

  
• What are antibodies?

  Proteins produced by white blood cells against antigens.

  
• Why are antibiotics ineffective against viruses?

  Because viruses do not have cell walls, cell membranes, or ribosomes.

  
• What can accelerate the emergence of antibiotic-resistant bacteria?

  The misuse and overuse of antibiotics.

  
• What are the effects of antibiotics on bacteria?

  • Prevent synthesis of bacterial cell walls (e.g., penicillin)
  • Break up the bacterial cell membrane (e.g., polymixin)
  • Bind to bacterial ribosome (e.g., tetracycline)
  • Inhibit enzyme action in cytoplasm (e.g., sulfa antibiotics)

  
• What should be done to prevent antibiotic resistance in bacteria?

  A course of antibiotics should be completed as prescribed.