Chapter 12- Lesson 2 & 3

The exchange of infectious material from its origin to a susceptible individual is called ________________ ________________.

The exchange of infectious material to a susceptible person by a source that acts solely as a carrier is called ______________ ______________.

An __________ infection occurs in unexpectedly large numbers.

A ___________ infection effects an enormous number of people and spreads to much of the world.

An ___________ infection naturally occurs at low levels in a particular area.

A ______________ can help stop the spread of an infectious disease.

________ _________ reduces the occurrence of infectious diseases that are transmitted by respiratory droplets, blood, or direct skin contact.

____________ are substances that target and kill many kinds of pathogenic bacteria.

_____________ can help keep the virus under control while the body fights the infection.

The __________ __________ continually defends the body against infection.

A ________________ is a white blood cell that destroys microorganisms.

A ___________ simulates phagocytes and other white blood cells important for immunity.

Resistance to infectious diseases depends on a healthy immune system and a _________________.

The immune system benefits from good ___________ and __________.