Identificación de infección primaria y secundaria al virus de la rubéola mediante la detección de la avidez de la IgG en muestras de un brote en el 2004 en Cuba

Rubella infectious diseases affect children and young adults and when they occur during the first trimester of pregnancy, cause congenital malformations in the newborn. In the National Reference Laboratory (NLR) of measles, rubella and mumps from the Tropical Medicine Institute ¨Pedro Kouri¨, the IgG Avidity Index (AI) detection was carried out to 15 paired serum samples, which corresponded to same number of patients infected with this virus in two Cuban provinces in 2004. The samples were positive to virus- specific IgM antibodies, in addition seroconversion or an increase of > 4 fold of the titers in the sera of the acute and convalescence phase using the hemagglutination inhibition assay (HIA). The AI value showed a primary infection to rubella virus in 13 (86.6%) of the patients studied, and a secondary infection in 2 (13.3%) of them. The IgG avidity antibody detection is a reliable alternative tool for distinguishing between primary and secondary rubella virus infection and for strengthing the diagnosis of this disease in Cuba