My husband is a Hodgkins Lymphoma survivior. Like he says, "I wouldn't wish this disease on Anybody."
Why is there no transmission in a given situation? Because everybody is being careful...as all infected people should be: conscientious about transmissibility. I have separated from my husband and eleven year old son. Before I researched vectors and transmission, I missed birthdays, holidays, and my son's black-belt because I suspected I was contagious. It is up to the individual patient whether to increase transmission potential by contacting others while actively shedding the pathogen. Skin brushing followed by a shower with dandruff shampoo, blow-drying hair and putting clothes that are to-be-worn immediately in the dryer Prior to wearing will eliminate most risk of transmission on a daily basis, assuming the patient does not touch lesions.