Hi. The first thing you should know is rubella is generally transmitted by droplet spread I.e by sneezing,coughing or by direct contact with secretions of infected persons and as far as the CMV infection is concerned it spreads by saliva,urine,sexual contact. Generally they have symptoms of loss of appetite,fever, rashes, sore throat, muscle pain, sometimes patient can be asymptomatic. Rubella igg high titre might be because of past infection or it could be because of vaccination but CMV igg usually indicates past infection and it might be also due to developing immunity against the infection but it can also co-exist with current acute infection. So get a PCR DNA test done to rule out acute CMV infection and get a opinion of a physician for further management.