The importance of implementing, monitoring and evaluating congenital rubella syndrome surveillance

Rubella, once considered being a mild, benign rash illness, gained public health significance in 1941 when Gregg [1] associated the significance of congenital cataracts with rubella during pregnancy. In 1962–1965, a rubella pandemic resulted in approximately 12.5 million rubella cases, 20,000 infants born with congenital rubella syndrome (CRS), 11,250 fetal deaths (fetal wastage and abortions), and 2,100 neonatal deaths in the US alone [2]. This devastating epidemic and the ability to isolate and attenuate the virus expedited the development of a vaccine against rubella [3]. With the licensure of rubella vaccines in 1969, the goal of the rubella vaccination program was the prevention of congenital rubella infection (CRI) in the US [4]. CRI encompasses all outcomes associated with intrauterine rubella infection, including miscarriage, stillbirth, abortion, combinations of birth defects known as CRS, or asymptomatic infection (also known as infection only). To monitor the impact of the vaccination program, the US implemented CRS surveillance in addition to previously established rubella surveillance. The rationale for focusing on CRS surveillance instead of CRI is that CRS is easier to quantities; confirm diagnosis and monitor compared with CRI.