Single Celled Organism. Can Live Almost Anywhere. Multiply Rapidly – Under Perfect Conditions, in 15 ½ Hours, 1 Multiplies Into 4 Billion

Bacterium – single celled organism. Can live almost anywhere. Multiply rapidly – under perfect conditions, in 15 ½ hours, 1 multiplies into 4 billion. In most healthy individuals, body’s immune system attacks the invading bacteria.

Virus – not a living cell. Smallest known type of infectious agent. Inner core of genetic material surrounded by a protective shell. Highly specific in types of cells that they invade. Usually run course and eventually killed by immune system.

Rickettsias- look like small bacteria. Multiply by invading cells (like the virus does). Most are found in the intestinal tracts of insects – notably fleas – also mice, ticks, and mites. Passed to humans and animals through bites or feces on the skin

Protozoan – single celled organisms. Much larger and more complex than bacteria. Common in tropical areas with poor sanitation.

Fungi – organism that cannot make its own food. Prefers dark, damp environments. Usually invades deep tissue of hair, nail, and skin.

Diseases by Bacteria: o Tuberculosis . Highly contagious infection that most often affects the lungs . Spread by airborne droplets . Symptoms include coughing (sometimes with blood), chest pain, shortness of breath, fever, sweating, poor appetite, weight loss. o Strep Throat . Spread by airborne droplets . Symptoms include sore throat, fever, general feeling of illness, enlarged lymph nodes in the neck o Meningitis . Infection of the membranes covering the brain and spinal cord. . Bacterial is more dangerous . Caused by an infection elsewhere in the body (travels through bloodstream) . Symptoms include fever, severe headache, nausea and vomiting, sensitivity to light, stiff neck

Diseases by Virus: o Common Cold: . Transmitted by airborne droplets, contact with infected person or contaminated objects. . Symptoms include runny nose, sneezing, sore throat, and headache.

o Influenza . Transmitted by airborne droplets . Symptoms include chills, fever, headache, muscle aches, weakness o Encephalitis . Inflammation of the brain . Usually caused by a bite of an infected mosquito . Starts with a headache and fever, untreated can progress to hallucinations, paralysis, loss of consciousness, coma o Meningitis . Infection of the membranes covering the brain and spinal cord. . Viral is more mild . Caused by an infection elsewhere in the body (travels through bloodstream) . Flu like symptoms o Mononucleosis . Also known as the “kissing disease” . Spread by direct contact touching, sharing food/drinks . Symptoms include chills, fever, sore throat, fatigue, swollen lymph nodes . Complete bed rest is needed in the care of mono o Hepatitis A/B/C . Inflammation of the liver . Symptoms include Jaundice (yellowing of the skin and whites of the eyes), fever nausea, loss of appetite, pain in the abdomen . Severe cases can lead to permanent liver damage . A spread by food and water contaminated with feces . B found in all body fluids especially blood . C spread through infected blood o HIV . See HIV Unit

Diseases by Rickettsias: o Typhus o Spread by ticks, mites, fleas, or lice o Symptoms include fever lasting one to several weeks, chills, headache, muscle pain, body rash o Also often a painful sore at the site of the bite

Diseases by Protozoan:

Diseases by Fungi: Ringworm Athlete’s Foot