Pathogens Bacteria and Viruses Pathogens Organism that causes

Pathogens Bacteria and Viruses

Pathogens � Organism that causes disease � Types: › Bacteria, viruses, fungi, protists � Examples? › › › Plasmodium malaria HIV AIDS HPV genital warts, cervical cancer Dermatophytes athlete’s foot Salmonella food poisoning

How do they spread? � Coughing, sneezing, and physical contact � Exchange of body fluids � Contaminated water or food � Animal vectors

Emerging Diseases � Formerly diseases › › › unknown or newly evolved Ex. AIDS in the 1980’s West Nile Virus H 1 N 1 Drug-resistant TB Ebola � We often do not have a way to control them � Our bodies have little resistance to them

Emerging Diseases

Bacterial Diseases � How do they cause disease? › Destroy living cells �Directly infect cells �Indirectly – may trigger an immune response that damages cells › Releasing toxins �Poisons interfere with our cells’ activities �E. g. Botulism paralyzes muscles � Other examples: › TB, Tetanus, Lyme disease, Strep throat

Controlling bacterial infections � � � � Wash surfaces/hands washes away bacteria Use chemicals disinfectants Properly store our food refrigeration Cook food fully kills bacteria Heat sterilization e. g. surgical tools Antibiotics treat bacterial infections Vaccines – prepare immune system

Viral Diseases � How do they cause disease? › Attack and destroy specific types of cells › Can change patterns of growth and development of cells leads to cancer � Examples: › Common cold, influenza (flu), HIV/AIDS, chicken pox, Hepatitis B, HPV

Controlling viral diseases � Vaccines � Good hygiene – wash hands, use Kleenex! � Avoid contact with sick individuals � Antibiotics DO NOT work against viruses � Few antiviral drugs