Bacteria and viruses are bugs that can cause infections. You need a microscope to see them. That is why there are also called microscopic organisms or microbes.

Bacteria

Bacteria are microbes that can survive in the human body, in the air, in water, in soil, …, but they don’t need living cells for their survival. Bacteria can multiply (divide) very fast.

Bacteria cause diseases such as:
· Pneumonia
· Meningitis
· Wound infections
· Some throat and ear infections

Antibiotics can however kill bacteria and thus are capable of saving lives.

Viruses

Viruses are much smaller than bacteria and need human living cells to survive (like a parasite). Indeed, in order to multiply they useliving cells whichthey penetrate. How? By ‘forcing’ the cell to make copies of the virus. Afterwards, the host cell is destroyed and the virus starts spreading inside the human body.

Viruses cause diseases such as:
· Common cold
· Acute bronchitis
· Flu
· Most throat and ear infections
· Measles
· Rubella
· Viral hepatitis
· AIDS

Antibiotics are NOT active against viruses.