infectious diseases

• Infectious diseases can be spread from person to person, while non-infectious diseases cannot
• Infectious diseases are caused by pathogens such as bacteria and viruses and can be spread through bodily fluids, food, and water
• Examples of bodily fluids include sweat, blood, saliva, and mucus
• Diseases can be infectious (transmissible) or non-infectious
• Signs of a disease can be observed or measured such as rashes, fever, cough and vomitting
• Influenza, pneumonia, COVID-19, and HIV/AIDS are examples of infectious diseases
• Non-infectious diseases are not caused by pathogens and can be inherited or result from environmental factors and lifestyle choices
• Infectious diseases can be spread through droplets in the air/respiratory droplets, direct contact, and contaminated food/water
• Droplets in the air: When a person coughs or sneezes, respiratory droplets containing pathogens can infect others
• Direct contact: Diseases can spread through person-to-person contact or sexual intercourse
• Contaminated food and water: Pathogens like bacteria can contaminate food and water if not stored or handled properly
• Ways to reduce infection include vaccination, wearing masks, washing hands, avoiding infected individuals, and disinfecting surfaces
• Vaccines contain agents that resemble pathogens and stimulate white blood cells to produce antibodies for protection
• Antibiotics kill bacteria but are ineffective against viruses
• Misuse and overuse of antibiotics can lead to antibiotic-resistant bacteria
• Antibiotics work by weakening bacterial cell walls, breaking up cell membranes, and inhibiting protein synthesis in ribosomes
• Antibiotics are ineffective against viruses because viruses lack cell walls, cell membranes, and ribosomes
• To reduce antibiotic resistance, antibiotics should not be misused or overused, the full course should be completed, and they should only be used when necessary
• Disease: condition that causes the body to function less effectively, it produces specific signs and symptoms.
• Vaccine: contains an agent that resembles a pathogen and prevents infectious diseases by stimulating white blood cells to quickly produce antibodies when the pathogen invades the body
• Vaccines work by stimulating white blood cells to produce antibodies to destroy the pathogens, and some white blood cells will remain in the bloodstream and will recognise them and produce antibodies to destroy them.
• Virus: does not have cell wall, cell membrane and ribosomes
• Bacteria: have cell walls, cell membrane, ribosome
• Antibiotics: -weaken cell wall allowing water to enter through osmosis, swell and burst - breaking up cell membrane -prevent ribosomes from making proteins and enzymes -inhibit some enzymes > growth of bacteria
• Antiviral drugs: medication that help the body fight off disease causing viruses
• Antibiotic resistance:

  • more sensitive bacteria are killed 
  • less sensitive are not easily killed and may survive
  • if course of antibiotic is not completed, less sensitive bacteria that survive will multiply and increase in numbers
• Vaccine effectiveness for new mutated strains:

  • Antibodies produced are specific in action against particular strain of virus
  • Mutated strains may be structurally different from original strain
  • Antibodies produced will be ineffective against mutated strain