Page 4 - 2. Lesson Notes- Infectious Disease

• The antibiotic penicillin blocks

the bacterial processes that
build the cell wall. As a result,

the growing bacteria are

unable to make cell walls and
die easily.

• The antibiotics work against a
group of many similar bacteria.

• Viruses do not use these

pathways. Antibiotics works
against the bacterial part of the

infection, not the viral part.

Ex- If we have a common cold then taking antibiotics would not decrease the severity or

duration of the infection because Antibiotics work against the bacterial part of the
infection, not the viral part.

Means of spread of infectious diseases:

Infectious diseases spread from one infected person to other normal person by a variety
of method:

1. Air-borne diseases: (example- common
cold, influenza and tuberculosis)

Some infectious diseases the spread by

the dissemination of droplet nuclei
(aerosols) that remain infectious when

suspended in air over long distances and
time.

2. Through contaminated food and water: (example- cholera, Hepatitis A)

A large number of infectious diseases can also spread through contaminated food