Pathogens Eco-Science Chapter 21

Water Pollution and disease are closely related Many disease-causing organisms spend at least part of their life cycle in the water Examples: parasites, bacteria, and viruses

What is a pathogen? Pathogens- Parasites, bacteria, and viruses that cause disease in living things How do these ‘guys’ get into the water? Through raw sewage or animal waste they are then passed on to others who come in contact with the contaminated water Pathogens result in more human illness and deaths than any other environmental factor!

Typhoid Fever Spread by contaminated food, drink or water Affects intestines, lymph nodes, spleen, etc. Symptoms: Fever, Rash, Weakness, Diarrhea, etc.

Cholera Cholera occurs in places with poor sanitation, crowding, war, and famine caused by a bacterium that releases a toxin that increases the release of water in the intestines causes a large amount of watery diarrhea.

Schistosomiasis Spread by a microscopic worm that enters the skin of people who walk in contaminated water (water infected with human waste) Worms attack the liver, urinary bladder, and intestines Symptoms: fever, chills, lymph node enlargement, itchy rashes FACT: Causes more than 1 million deaths each year

Malaria Transmitted to humans by the bite of an infected mosquito Note: that it is not transferred via direct contact with contaminated water BUT water is the breeding ground for the mosquito… A parasitic disease that involves high fevers, shaking chills, flu-like symptoms, and anemia. FACT: Malaria kills more than 3,000 children under the age of five each year and more than 1.5 million each year.