The term mysophobia comes from the Greek μύσος musos, uncleanness and φόβος phobos, fear.
https://en.wikipedia.org/wiki/Mysophobia
Obsessive-Compulsive Disorder Takes Many Forms. Obsessive-compulsive disorder (OCD) consists of unwanted thoughts and repetitive behaviors intended to reduce the anxiety caused by the unwanted thoughts.
http://www.brainphysics.com/contamination.php
Mysophobia, more commonly known as germaphobia or germ phobia,. is a pathological fear of germs, dirt, and above all of contamination. A phobia is an irrational fear of an object or situation. Most people understand that there are good germs (such as bacteria, which helps us digest food) and harmful germs (like cold and flu viruses, salmonella and E. coli).
http://www.epigee.org/mental_health/mysophobia.html
Mysophobia is common in the United States. Some experts link the growing incidence of this disorder to Americans' general perception of the world as being a dangerous, uncontrollable place. Media coverage of the AIDS epidemic may also be a contributing factor.
http://www.epigee.org/mental_health/mysophobia.html
Mysophobia results in repeated, unreasonable behavior and actions. These can include: 1  excessive washing, for example, repeated hand washing (an action which paradoxically makes the individual more prone to infection). 2  avoiding activities that are deemed unclean by the individual, such as using public bathrooms.
http://www.epigee.org/mental_health/mysophobia.html
Ophidiophobia – The fear of snakes. The fear of snakes or Ophidiophobia is the second most common zoophobia (right after the no. 1 phobia on this list) affecting nearly 1/3rd of the adult human population. Like the phobia mentioned below, the fear of snakes also has evolutionary roots.
http://www.fearof.net/top-10-phobias-of-all-time/
Concerns about Germs and Dirt. Over half of all OCD patients experience contamination fears that involve washing compulsions. OCD patients with washing compulsions worry about becoming contaminated and often describe contaminated objects as disgusting.
http://www.brainphysics.com/contamination.php
One washing is never enough because of the worry that a critical spot may have been missed. Therefore a person with contamination OCD may wash their hands repeatedly until the soap is gone and their hands are chapped and bleeding (which may paradoxically make the person more prone to infection).
http://www.brainphysics.com/contamination.php
In other words, a behavior that is good and might help the species survive, has somehow become broken and taken to its extreme. For example, from an evolutionary perspective, it would be theoretically adaptive to avoid contact with disease-causing objects and other objects that had touched it.
http://www.brainphysics.com/contamination.php
Mysophobia, also known as verminophobia, germophobia, germaphobia, bacillophobia and bacteriophobia, is a pathological fear of contamination and germs. The term was coined by Dr. William Alexander Hammond in 1879 when describing a case of obsessive-compulsive disorder (OCD) exhibited in repeatedly washing one's hands. Mysophobia has long been related to the OCD of constantly washing one's hands.
https://en.wikipedia.org/wiki/Mysophobia
what is handwashing phobia called
Handwashing phobia is called mysophobia. Hand washing phobia is called as mysophobia.