Scabies

Scabies is a highly contagious parasitic skin disease caused by the itch mite (Sarcoptes scabiei).
It is acquired through close contact with an infested individual or contaminated clothing and is most prevalent among those living in crowded and unhygienic conditions. Personal hygiene is an important preventive measure and access to adequate water supply is important in control.

The principal sign of the disease is a pimple-like rash that is most commonly found on hands, especially the webbing between the fingers, the skin folds of the wrist, elbow or knee, the penis, the breast or the shoulder. Infestation often causes intense itching all over the body, especially at night.
 

Scabies mites are found worldwide, affecting all socioeconomic classes and in all climates. Epidemics have been linked to poverty, poor water supply, sanitation, and overcrowding. There are about 300 million cases of scabies in the world each year.

Click here to learn for more information about waterborne diseases, dimension of the problem, transmission, prevention.

Sources:
http://www.who.int/water_sanitation_health/diseases/scabies/en/
http://en.wikipedia.org/wiki/Scabies
  Picture:
http://images.google.com/images?q=scabies&hl=en&lr=&rls=GGLD,GGLD:2005-12,GGLD:en&start=20&sa=N