My brother was diagnosed with german measles. what does this mean?

Rubella: German measles is an older name for a viral infection called rubella. This is usually a mild disease with minor rash and other symptoms. Most people have received immunizations for this infection (mmr vaccine). Rubella can cause severe fetal malformations if a pregnant mother catches the disease.

German Measles: Most of the population get vaccinated to this. It will run it's course with him and he needs to keep away from un-vaccinated people. It is more of a problem with pregnant patients who have no immunity because it can cause mental retardation in the baby.