Viremia and the presence of rubella virus in the throat of infect persons bear which of the following relationships to the onset of the rube rash?: (A) They precede the rash by 5 to 7 days, (B) They precede the rash by 1 to 2 days, (C) They occur coincidentally with the rash, (D) They occur 1 to 2 days after the rash
Answer is A. Both viremia and the excretion of virus from the throats of persons infected with rubella occur 5 to 7 days before the appearance of the characteristic maculopapular rash. The importance of this relationship is that by the time a pregnant woman first notes the appearance of a rash on one of her children, she has already been exposed to the disease and may, in fact, be infected. If one member of a family develops rubella, all other members who are susceptible to the disease usually become infected.