Which of the following is the major difference between vertical and horizontal disease transmission?

• A. Vertical transmission only occurs with genetic disorders. Horizontal transmission occurs with infectious diseases.
• B. Vertical transmission only occurs between mother & baby. Horizontal transmission is any other mode of transmission.
• C. Vertical transmission occurs between mother & baby. Horizontal transmission occurs between father & baby.
• D. Vertical transmission is a form of indirect transmission. Horizontal transmission is a form of direct transmission.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the definitions of vertical and horizontal transmission in microbiology. Vertical transmission refers to the passage of a pathogen from parent to offspring, typically from mother to baby during pregnancy, childbirth, or breastfeeding.
2. Step 2: Recognize that horizontal transmission involves the spread of infectious agents between individuals other than parent to offspring. This can occur through direct contact, airborne droplets, vectors, or contaminated surfaces.
3. Step 3: Identify that vertical transmission is specifically mother-to-child, not involving genetic disorders exclusively, but rather the transfer of infectious agents during the perinatal period.
4. Step 4: Note that horizontal transmission encompasses all other modes of disease spread, including person-to-person contact, environmental exposure, or vector-borne transmission.
5. Step 5: Conclude that the major difference lies in the direction and mode of transmission: vertical transmission is mother to baby, while horizontal transmission includes all other forms of disease spread between individuals.