Measles, Mumps, and Rubella - Centers for Disease Control and ...

Vol. 47 / No. RR-8 MMWR 45rubella-specific antibody levels that do not decline at the rate expected from passivetransfer of maternal antibody (i.e., the equivalent of a twofold decline in HI titer permonth). However, some infected infants may have low antibody levels because ofagammaglobulinemia or dysgammaglobulinemia.In some infants with CRS, rubella virus can persist and can be isolated from nasopharyngealand urine cultures throughout the first year of life or longer (229 ).Children with CRS should be presumed infectious at least through the first year of lifeunless nasopharyngeal and urine cultures are negative for virus after age 3 months(230 ). Some authorities suggest that an infant who has CRS should be consideredinfectious until two cultures of clinical specimens obtained 1 month apart are negativefor rubella virus (230 ). Precautions should be taken to ensure that infants with CRS donot cause additional rubella outbreaks. Specifically, all persons who have contact witha child with CRS (e.g., care givers, household contacts, medical personnel, laboratoryworkers) should be immune to rubella (Table 1) (see Documentation of Immunity andRoutine Vaccination).Rubella Outbreak ControlOutbreak control is important for eliminating CRS. Aggressive responses to outbreaksmay interrupt chains of transmission and can increase vaccination coverageamong persons who might not be protected otherwise. Although methods for controllingrubella outbreaks are evolving, the main strategy should be to define targetpopulations for rubella vaccination, ensure that susceptible persons within the targetpopulations are vaccinated rapidly (or excluded from exposure if a contraindication tovaccination exists), and maintain active surveillance to permit modification of controlmeasures as needed.Control measures should be implemented as soon as a case of rubella is confirmedin a community. This approach is especially important in any outbreak setting involvingpregnant women (e.g., obstetric-gynecologic and prenatal clinics). All persons atrisk who cannot readily provide laboratory evidence of immunity or a documentedhistory of vaccination on or after the first birthday should be considered susceptibleand should be vaccinated unless vaccination is contraindicated (Table 1) (see Documentationof Immunity).Rubella Outbreaks in Schools or Other Educational InstitutionsAn effective means of terminating rubella outbreaks and increasing rates ofvaccination quickly is to exclude from possible contact persons who cannot providevalid evidence of immunity. Experience with measles outbreak controlindicates that almost all students who are excluded from school because theylack evidence of immunity quickly comply with vaccination requirements and arepromptly readmitted to school. Persons exempted from rubella vaccination formedical, religious, or other reasons should also be excluded from attendance.Exclusion should continue for 3 weeks after the onset of rash of the last reportedcase in the outbreak setting. Less rigorous approaches (e.g., voluntary appealsfor vaccination) have not been effective in terminating outbreaks.