Congenital Rubella Syndrome Surveillance in South Africa Using a Sentinel Site Approach: A Cross-sectional Study

Area of Science:

• Epidemiology
• Immunization
• Public Health

Background:

• Congenital rubella syndrome (CRS) comprises disorders from intrauterine rubella infection, with higher incidence in regions lacking rubella-containing vaccines (RCVs).
• The WHO African region is integrating RCVs into immunization schedules, necessitating baseline epidemiological data.
• This study focuses on the epidemiology of confirmed CRS in South Africa before RCV introduction.

Purpose of the Study:

• To describe the epidemiology of laboratory-confirmed congenital rubella syndrome (CRS) cases in South Africa.
• To establish baseline data for monitoring the impact of rubella-containing vaccine (RCV) introduction.
• To identify potential immunity gaps in young women regarding rubella.

Main Methods:

• A descriptive epidemiological study was conducted across 28 sentinel sites in South Africa.
• Laboratory-confirmed CRS cases were identified through a retrospective review (2010-2014) and a prospective surveillance system (2015-2017).
• Data collection involved medical record retrieval and monthly clinician reporting.

Main Results:

• A total of 42 CRS cases were identified in the retrospective phase and 53 in the prospective phase.
• The most common birth defects reported were congenital heart disease and cataracts.
• The median maternal age for CRS cases was 21 years (retrospective) and 22 years (prospective), with 98% of mothers aged 14-30.

Conclusions:

• Baseline CRS data are crucial for planning and monitoring RCV implementation within South Africa's Expanded Programme on Immunization.
• The high proportion of young mothers (14-30 years) among CRS cases suggests a potential rubella immunity gap in this demographic.
• These findings highlight the importance of RCV introduction to address the identified immunity gap and reduce CRS incidence.