Organisms: Protists (and Diseases)

Many waterborne illnesses are present in the world as a result of insect, bacterial, viral, or protist causes. 

What is a Waterborne Disease?
Any disease that can spread through contaminated water. The contamination can involve bacterial, viral or protozoan organisms. Some examples of waterborne diseases include cholera (bacteria), dysentery (bacteria or amoeba), cryptosporidiosis (protozoa), hepatitis A (virus)and giardia (protozoa). Infection can result not only from drinking the water but also from swimming in the water where it can enter the body in other ways such as through broken skin. Many poorer countries have limited uncontaminated water supplies so waterborne disease is a huge health issue worldwide.

Diarrhea occurs world-wide and causes 4% of all deaths and 5% 
of health loss to disability. It is most commonly caused by gastrointestinal 
infections which kill around 2.2 million people globally each year, mostly children in developing countries. The use of water in hygiene is an important preventive measure but contaminated water is also an important cause of diarrhea. Cholera and dysentery cause severe, sometimes life threatening forms of diarrhea
or river blindness is a parasitic disease with an insect vector that breeds in water. It is the world's second leading infectious cause of blindness. Controlling insect breeding sites in rivers is one of the pillars of prevention.
 Typhoid and paratyphoid fevers are infections caused by bacteria which are transmitted 
from faeces to ingestion. Clean water, hygiene and good sanitation prevent the spread of typhoid and paratyphoid.Contaminated water is one of the pathways of transmission of the disease.
 Cholera outbreaks can occur sporadically in any part of the world where water supplies sanitation, food safety and hygiene practices are inadequate. Overcrowded communities with poor sanitation and unsafe
drinking-water supplies are most frequently