6.1.2 Transmission of Pathogens

• What is a pathogen?

  A biological agent
• A disease is a specific abnormal condition that affects an organism, impairing its normal functions
• Pathogens cause illness, while diseases are the illnesses themselves.
• Match the pathogen with an example of a disease it causes:

  Bacteria ↔️ Salmonella

  Virus ↔️ Influenza

  Parasite ↔️ Malaria
• Arrange the following steps in the process of indirect transmission:

  1️⃣ Pathogen spreads through an intermediary

  2️⃣ Vector carries the pathogen

  3️⃣ Susceptible host comes into contact
• Direct transmission involves direct contact, air droplets, or vertical transmission
• Indirect transmission can occur through contaminated surfaces or airborne particles.
• Match the direct transmission method with its example:

  Physical contact ↔️ Touching an infected person

  Air droplets ↔️ Sneezing

  Vertical transmission ↔️ Mother to child
• The probability of infection through a fomite is inversely proportional to the volume of contact.
• What is an example of a disease transmitted through physical contact?

  Ringworm
• Vertical transmission occurs from mother to child during pregnancy, childbirth, or breastfeeding
• The rate of infection in direct transmission increases linearly with the population size.
• What is the causative agent of a disease?

  Pathogen
• Indirect transmission can occur through fomites, vectors, or airborne particles
• Arrange the following indirect transmission methods in order of complexity:

  1️⃣ Fomites

  2️⃣ Airborne particles

  3️⃣ Vectors
• Match the indirect transmission method with its example:

  Fomites ↔️ Influenza on doorknobs

  Vectors ↔️ Malaria spread by mosquitoes

  Airborne particles ↔️ Tuberculosis spores
• Vector-borne transmission requires a vector to carry the pathogen from one host to another.
• In vector-borne transmission, the pathogen is carried by a biological vector
• Arrange the steps in the vector-borne transmission process:

  1️⃣ Vector feeds on infected host

  2️⃣ Pathogen develops within vector

  3️⃣ Vector bites susceptible host
• The probability of infection in vector-borne transmission increases with higher pathogen concentration in the vector.
• What are vectors in vector-borne transmission?

  Insects or animals
• In vector-borne transmission, the vector first acquires the pathogen by feeding on an infected host
• Vectors can be mechanical or biological in vector-borne transmission.
• What is the primary method of pathogen spread in airborne transmission?

  Inhalation
• In airborne transmission, pathogens remain suspended in the air due to air currents
• A pathogen is a biological agent that causes illness.
• What is a disease in the context of pathogens?

  An abnormal condition
• Pathogens are transmitted through two primary modes: direct and indirect
• Give an example of direct transmission by air droplets.

  Coughing or sneezing
• Match the mode of transmission with an example:

  Direct Transmission ↔️ HIV spread through sexual contact

  Indirect Transmission ↔️ Tuberculosis spores in the air
• Physical contact is a method of direct transmission.
• Air droplets spread pathogens when infected individuals cough or sneeze
• What is vertical transmission an example of?

  Direct transmission
• What are fomites in indirect transmission?

  Inanimate surfaces
• Vectors, like mosquitoes, carry pathogens from one host to another, leading to indirect transmission
• Airborne particles are a method of indirect transmission.
• What are key factors influencing airborne transmission?

  Pathogen viability, air currents, environmental conditions
• Waterborne transmission occurs when pathogens spread through contaminated water sources
• Match the foodborne pathogen with its associated disease:

  Salmonella ↔️ Salmonellosis

  coli ↔️ E. coli infection

  Norovirus ↔️ Norovirus infection
• What are two types of contact transmission?

  Direct and indirect