Rubella Epidemiology in Africa in the Prevaccine Era, 2002–2009

Rubella virus infection is transmitted by respiratory droplets and causes a generally mild disease characterized by a rash and fever, primarily in children. However, infection in women during early pregnancy may cause fetal death or congenital rubella syndrome (CRS) in the infant [1]. CRS is a significant cause of deafness, blindness, congenital heart disease, and mental retardation [2]; although precise burden of disease is unknown, it is estimated that 110,000 CRS cases occur each year in developing countries. Rubella is vaccine-preventable; the primary objective of rubella-control programs is prevention of congenital rubella virus infection, which includes CRS. Rubella is among the small number of viral diseases considered to be potentially eradicable. Rubella can be eliminated in countries that have introduced routine rubella vaccination for children and achieved high coverage in the population. In September 2010, achievement of the goal of rubella and CRS elimination in the region of the Americas was announced by the Pan American Health Organization. However, countries that introduce rubella vaccine and achieve suboptimal vaccination coverage may be at risk for a paradoxical increase in susceptibility among older age groups, potentially leading to acquisition of rubella virus infections among women of childbearing age and to an increase in CRS cases. To decrease the risk of rubella virus infections among pregnant women and consequent CRS cases, the World Health Organization (WHO) recommends introduction of rubella vaccine should be considered only in countries that have achieved high (>80%) coverage with the first-dose measles-containing vaccine.

WHO recommends that countries without rubella vaccination programs should assess the burden of rubella and CRS. Integrated case-based surveillance with laboratory testing to detect measles and rubella is recommended in countries with an established measles elimination or rubella control goal. In Africa, several countries have conducted subnational rubella seroprevalence surveys; however, none has established routine surveillance for CRS.

Since 1999, as part of the WHO and United Nations Children\'s Fund (UNICEF) measles mortality reduction strategy in Africa, case-based surveillance with laboratory testing for all suspected measles cases has been established. By December 2008, 40 of 46 countries in the African Region of WHO—all except Algeria, Comoros, Guinea Bissau, Mauritius, Sao Tome and Principe, and Seychelles—established measles and rubella case-based surveillance following the WHO African Regional Office (AFRO) measles-surveillance guidelines [14]. Laboratory testing for rubella IgM antibody is recommended for specimens found to be negative or indeterminate for measles IgM antibody. Given that little is known about rubella in Africa, the researchers provide an overview of published seroprevalence surveys and analysis of surveillance and laboratory data as a baseline of prevaccine-era rubella epidemiology in Africa, in preparation for the introduction and widespread use of rubella vaccine throughout the region.