Page 4 - LN

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 and water. Disease causing organisms and harmful pollutants in the form of
chemicals can easily enter the body through food and drinks.

3. Sexually-transmitted diseases,STDs: These infections pass from infected
person to healthy one through sexual contact. The causes of STDs are bacteria

and viruses. Infectious diseases such as syphilis, Gonorrhoea (caused by
bacteria) and AIDS from one partner to the other. (caused by virus) are

transmitted by sexual contact f