Podcast
Questions and Answers
Which of the following methods describes direct transmission of infectious agents?
Which of the following methods describes direct transmission of infectious agents?
Which of these is an example of indirect transmission through a vector?
Which of these is an example of indirect transmission through a vector?
What characteristic must droplets possess to remain an effective mode of transmission?
What characteristic must droplets possess to remain an effective mode of transmission?
Which of the following best describes a vehicle for disease transmission?
Which of the following best describes a vehicle for disease transmission?
Signup and view all the answers
Which disease is NOT primarily transmitted by droplets?
Which disease is NOT primarily transmitted by droplets?
Signup and view all the answers
Which of the following is NOT one of Koch’s postulates?
Which of the following is NOT one of Koch’s postulates?
Signup and view all the answers
Which element is NOT part of the chain of transmission?
Which element is NOT part of the chain of transmission?
Signup and view all the answers
What is an example of direct transmission of disease?
What is an example of direct transmission of disease?
Signup and view all the answers
What is the primary goal of a pathogen in the transmission process?
What is the primary goal of a pathogen in the transmission process?
Signup and view all the answers
Which classification of immunity primarily involves antibodies acquired through vaccination?
Which classification of immunity primarily involves antibodies acquired through vaccination?
Signup and view all the answers
What is meant by indirect transmission of disease?
What is meant by indirect transmission of disease?
Signup and view all the answers
What is the first step a pathogen must accomplish to ensure disease transmission?
What is the first step a pathogen must accomplish to ensure disease transmission?
Signup and view all the answers
What type of transmission does the term 'vertical transmission' refer to?
What type of transmission does the term 'vertical transmission' refer to?
Signup and view all the answers
What is the primary method through which typhoid is spread by insects?
What is the primary method through which typhoid is spread by insects?
Signup and view all the answers
Which of the following diseases are primarily transmitted by mosquitoes?
Which of the following diseases are primarily transmitted by mosquitoes?
Signup and view all the answers
What percentage of the global burden of disease is attributed to insect-borne infections?
What percentage of the global burden of disease is attributed to insect-borne infections?
Signup and view all the answers
Which of the following is NOT a method of transmission for infectious diseases mentioned?
Which of the following is NOT a method of transmission for infectious diseases mentioned?
Signup and view all the answers
How can soil contribute to the transmission of infectious diseases?
How can soil contribute to the transmission of infectious diseases?
Signup and view all the answers
Which of the following microorganisms are prominently included among those transmitted by insects?
Which of the following microorganisms are prominently included among those transmitted by insects?
Signup and view all the answers
What role do filthy breeding habits of some insects play in the transmission of diseases?
What role do filthy breeding habits of some insects play in the transmission of diseases?
Signup and view all the answers
How do most vector-borne infections typically arise?
How do most vector-borne infections typically arise?
Signup and view all the answers
What is the primary function of Killer T-lymphocytes?
What is the primary function of Killer T-lymphocytes?
Signup and view all the answers
Which type of immunity is present from birth and inherited from the mother?
Which type of immunity is present from birth and inherited from the mother?
Signup and view all the answers
Which white blood cells are primarily responsible for phagocytosis?
Which white blood cells are primarily responsible for phagocytosis?
Signup and view all the answers
What distinguishes active immunity from passive immunity?
What distinguishes active immunity from passive immunity?
Signup and view all the answers
What is the role of Suppressor T-lymphocytes in the immune response?
What is the role of Suppressor T-lymphocytes in the immune response?
Signup and view all the answers
What is the primary function of the mucociliary escalator in the respiratory tract?
What is the primary function of the mucociliary escalator in the respiratory tract?
Signup and view all the answers
Which of the following best describes the blood-brain barrier?
Which of the following best describes the blood-brain barrier?
Signup and view all the answers
What role do B lymphocytes play in the immune response?
What role do B lymphocytes play in the immune response?
Signup and view all the answers
How do memory cells function in the immune system?
How do memory cells function in the immune system?
Signup and view all the answers
What is the primary function of saliva in the immune response?
What is the primary function of saliva in the immune response?
Signup and view all the answers
Which statement accurately describes T lymphocytes?
Which statement accurately describes T lymphocytes?
Signup and view all the answers
What is gingival crevicular fluid primarily composed of?
What is gingival crevicular fluid primarily composed of?
Signup and view all the answers
Which of the following components protects the body from infection through skin?
Which of the following components protects the body from infection through skin?
Signup and view all the answers
What mechanism helps reduce the risk of infection from wounds in the bloodstream?
What mechanism helps reduce the risk of infection from wounds in the bloodstream?
Signup and view all the answers
What distinguishes the immune system's ability to respond to previously encountered antigens?
What distinguishes the immune system's ability to respond to previously encountered antigens?
Signup and view all the answers
Study Notes
Koch's Postulates
- Koch's postulates are a set of criteria designed to establish a causal relationship between a microbe and a disease.
Transmission Chain
- The transmission chain describes the steps involved in the spread of an infectious agent.
- This chain includes:
- Agent: The pathogen causing the disease.
- Reservoir: The environment where the pathogen lives.
- Exit: How the pathogen leaves the reservoir.
- Mode of Transmission: How the pathogen travels to a new host.
- Portal of Entry: How the pathogen enters the new host.
- Susceptible Host: An individual who can be infected by the pathogen.
Classifying Transmission
- Horizontal Transmission: Disease spread between individuals of the same generation.
- Vertical Transmission: Disease spread from parent to offspring.
-
Direct Transmission: Physical contact between infected and susceptible individual.
- Kissing, sexual contact, body lesions.
-
Indirect Transmission: Contact with contaminated objects or vectors.
- Objects: Air, water, food, fomites (inanimate objects), blood, saliva.
- Vectors: Insects, ticks, and other living organisms that transmit disease.
Airborne Transmission
- Diseases spread through droplets released from infected individuals during coughing, sneezing, or talking.
- Droplets can remain suspended in the air for long periods.
- Airborne transmission requires the pathogen to be resistant to drying.
Waterborne Transmission
- Spread of disease through contaminated water.
- Often caused by excreta from infected animals or humans.
- Results in infection during bathing, washing, drinking, or food preparation.
Vector-Borne Transmission
- Diseases transmitted through vectors like insects.
- Not all vector-borne diseases are caused by the insect itself, but by organisms they carry.
- Examples include malaria, West Nile virus, dengue fever, and yellow fever.
Soil Transmission
- Infections from contact with the soil.
- Some microorganisms, like tetanus spores, can survive in soil for long periods.
- Soil can also transmit parasites, like hookworms.
Food and Faecal-Oral Transmission
- Often associated with pathogens that infect the digestive system.
- Enter through ingestion of contaminated food or water.
- Shed from the body through faeces.
Host Defences
- The body has various defence mechanisms for preventing disease.
- These include:
- Tears
- Saliva
- Stomach acid
- Skin
- Mucociliary escalator
- Blood brain barrier
- Fatty acids and salts
- Gingival crevicular fluid
- Blood
Mucociliary Escalator
- The respiratory tract is lined with mucus and cilia that trap and remove microbes.
Skin
- The skin's tough outer layer, keratin, provides a mechanical barrier to infection.
- Mucous membranes, such as the alimentary and respiratory tracts, eyes, and gingival sulcus, are susceptible to infection as they are not keratinized.
Dealing with Ingress
- The immune system is the body's primary defence against pathogens.
- Lymphocytes are specialized white blood cells responsible for immune responses.
- B lymphocytes produce antibodies, which bind and neutralize foreign antigens.
- T lymphocytes directly destroy infected or cancerous cells.
- Phagocytosis is the process of engulfing and digesting microbes by phagocytes.
Immunity
- Natural immunity is present from birth and is inherited.
- Acquired immunity is developed throughout life and is characterized by the production of antibodies.
- Active immunity is gained through exposure to an infectious agent.
- Passive immunity is obtained through the transfer of pre-formed antibodies.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz explores Koch's postulates and the transmission chain of infectious diseases. It covers key concepts like modes of transmission, reservoirs, and the classification of disease spread. Test your understanding of how pathogens cause infections and their routes of transmission.