So the cause for OCD is unknown and doctors cant find out why people have OCD. 
That is a huge issue that needs to be resolved, I have a couple of friends that have OCD.
people who are workaholics and people with miserliness are often the ones affected by OCD
Yes but my friend is the opposite but he has a fear of germs and needs to have thing symmetrical or in perfect order. 
I myself have a slight OCD for having everything perfectly in order and also a clean house is a must
It could be considered OCD or could just be good habits, regardless in my friend you can tell its an extreme case. Whenever I look at him weird he just tells me "you know how i am".
Indeed, In some cases it has been reported that OCD can occur before an infection.