Principles of Medicine in Africa

Rubella or ‘little red’ is one of six classic childhood illnesses characterized by fever and a rash. It is a mild febrile illness of little direct clinical importance. It has a world-wide distribution and tends to occur in epidemics. Its main relevance is when infection occurs during the first trimester of pregnancy, when there is a high incidence of serious congenital abnormalities (WHO, 1999). This can be prevented by vaccination and, since man is the only known host, it is theoretically possible to eliminate the disease.

The problem in Africa

Rubella is not yet included in the childhood immunization strategy of any sub-Saharan country. Two-thirds of young adults have been exposed, and congenital rubella syndrome (CRS) continues to be an important and under-recognized problem, affecting 0.1–0.2 per 1000 live births (Clarke et al., 1980; Cutts et al., 1997).

Biology

Rubella is caused by a single-stranded RNA virus from the Togaviridae family, which consists of a capsid and an envelope protein with only one antigenic strain. It is transmitted by airborne droplets but can also be passed on by direct contact with recently contaminated material. Viral shedding from the upper respiratory tract begins around 10 days after infection and the incubation period is 2–3 weeks. Patients are considered to be infectious from 1 week before to 1 week after onset of the rash, and children should be excluded from school and avoid contact with pregnant women during this time. Rubella is inactivated by ultraviolet light, 1 per cent sodium hypochlorite and 70 per cent ethanol (WHO, 2007).