Infectious Diseases Overview

Infectious Diseases

• Infectious diseases can be spread from person to person.
• Non-infectious diseases cannot be spread from person to person.
• Examples of infectious diseases include influenza, HIV, and pneumococcal disease.
• Examples of non-infectious diseases include liver cirrhosis due to excessive alcohol consumption, and other diseases associated with pollution.
• Infectious diseases are caused by pathogens such as bacteria and viruses.
• Pathogens are microorganisms that lead to disease.
• Pathogens can spread via body fluids, food, and water.
• A disease causes the body to function less effectively, creating symptoms like fever, coughing, and weight loss.
• Infection occurs when a pathogen enters the body and begins to reproduce.

Learning Outcomes

• Candidates should be able to state that infectious diseases can spread from person to person, while non-infectious diseases cannot.
• Candidates should be able to identify examples of infectious and non-infectious disease.
• Candidates should be able to explain that infectious diseases are caused by pathogens such as bacteria and viruses, which are transmitted through body fluids, food, and water.
• Candidates should be able to state signs and symptoms of influenza (caused by the influenza virus) and pneumococcal disease (caused by the bacteria, pneumococcus).
• Candidates should be able to describe the transmission and methods to reduce the transmission of influenza virus and pneumococcus.
• Candidates should state that vaccines contain an agent that resembles a pathogen, stimulating white blood cells to quickly produce antibodies.
• Candidates should state that antibiotics kill bacteria but are ineffective against viruses.
• Candidates should explain that the misuse and overuse of antibiotics may accelerate the emergence of antibiotic-resistant bacteria.
• Diseases are conditions affecting body functions.
• Infectious and non-infectious diseases are different categories of illness.
• Pathogens, such as bacteria and viruses, cause infectious diseases.
• Infection occurs when a pathogen invades the body.
• A disease might not require an infection to manifest.

Transmission of Infectious Diseases

• Pathogens can spread through droplets in the air, contaminated food or water, direct contact (e.g., sexual intercourse, touching contaminated surfaces), and animal vectors.
• Droplet transmission occurs when an infected person coughs, sneezes, or talks, and droplets with pathogens are inhaled by those near them.
• Direct contact involves physical contact during sexual contact or non-sexual interactions, like shaking hands or touching contaminated surfaces.
• Contaminated food and water can contain pathogens, which can lead to water-borne or food-borne illness.
• Animal vectors, such as insects or other animals, can carry pathogens.

Transmission of Pneumococcal Disease

• Transmission occurs through respiratory droplets (coughing and sneezing).

Signs and Symptoms of Pneumococcal Disease

• Symptoms include fever, headache, vomiting, cough, chest pain, and rapid breathing.
• Additional symptoms may include signs of pneumonia, shortness of breath, chest pain, fatigue and muscle aches.

Methods to Reduce Transmission (Pneumococcal Disease)

• Get pneumococcal vaccination.
• Take prescribed antibiotics.
• Maintain safe distance.
• Cover mouth and nose when coughing.
• Wear masks to minimise spread.
• Wash hands.
• Avoid touching eyes, mouth, and nose.

Vaccines

• Vaccines contain an agent resembling a pathogen.
• They stimulate white blood cells to produce antibodies against that pathogen.
• Vaccines contain a weakened or dead version of a virus or bacteria.
• If the body is exposed to the actual pathogen later, it has antibodies already to fight it.
• This helps protect against disease.

Antibodies

• Pathogens have specific proteins on their surfaces called antigens.
• White blood cells identify these antigens and produce specific antibodies.
• Antibodies bind to antigens and destroy the pathogens.

Antibiotics

• Antibiotics are drugs used to treat bacterial infections.
• They work by targeting bacterial structures, like cell walls or ribosomes.
• They can weaken the bacterial cell wall or inhibit the growth of bacteria in other ways, thereby killing them
• Antibiotics are not effective against viruses.
• Completing the full antibiotic course helps prevent antibiotic-resistant bacteria.
• Misusing or overusing antibiotics promotes the development of resistant bacteria.

Antibiotics Resistance

• Antibiotic resistance can arise if a bacteria is exposed repeatedly to a certain drug.
• Some bacterial cells might survive the initial doses.
• The surviving bacteria then multiply, making more bacteria resistant to the antibiotic.
• Completing the full course of antibiotics is vital to effectively killing bacteria before resistance has a chance to start.

Reducing Antibiotic Resistance

• Complete the full course of antibiotics.
• Use the antibiotic only when necessary.
• Avoid unnecessary use on non-bacterial infections.

This quiz covers the fundamental concepts of infectious and non-infectious diseases. It includes the definitions of pathogens and how diseases spread, along with examples of each type. Participants will enhance their understanding of the differences and implications of these diseases.