Infectious Disease YouTube Video: Meningitis Outbreak http://www.youtube.com/watch?v=UTzgN9J3y58

WHAT IS AN INFECTIOUS DISEASE? Bacteria, viruses, protozoans, fungi, and other parasites called pathogens are capable of causing a change that disrupts the homeostasis in the body.

Any disease caused by the presence of pathogens in the body is called an infectious disease. The main sources of pathogens are soil, contaminated water, and infected animals, including other people

Not all microorganisms are pathogenic; your body is host to billions of microorganisms, most of which are bacteria. These microorganisms have a symbiotic relationship with your body helping to keep harmful bacteria and other microorganisms from growing.

If beneficial organisms are eliminated from your body, pathogens can establish themselves and cause infectious disease. In addition, if beneficial organisms enter areas of the body where they are not normally found, these formerly harmless organisms can become potential pathogens

Disease Cause Affected Organ Transmission Smallpox Virus Skin Droplet Influenza Respiratory system Direct contact HIV/AIDS Immune system Body Fluid Hepatitis B Liver Tetanus Bacteria Nervous system Puncture Wound Strep Throat Tuberculosis Respiratory

RESERVOIRS OF PATHOGENS Main source of human disease pathogens is the human body, these people may or may not display symptoms of the illness. These carriers are a significant reservoir of infectious disease.

Other people may communicate the disease before they experience symptoms. Animals are the other main reservoir for pathogens, making the eradication of certain pathogens almost impossible.

TRANSMISSION OF DISEASE Pathogens can be transmitted to a host from a reservoir four main ways; By direct contact; exchange of body fluid especially during sexual intercourse By an object; people handle contaminate objects then touch face, nose, eyes, etc… Through the air; person coughs or sneezes spreading droplets which are then inhaled By a vector; insects such as mosquitos, ticks spread pathogens between hosts or reservoirs