Identification of congenital rubella syndrome in Sudan.

BACKGROUND: Epidemiological data about congenital rubella syndrome (CRS) are scarce and rubella vaccine is not yet included in the childhood immunization schedule in Sudan. This study aimed to identify and describe CRS cases among Sudanese infants with congenital eye or heart defects. METHODS: Between February and September 2010, paired oral fluid and dried blood spot samples were collected from 98 infants aged up to 12 months. These infants were enrolled during their visits to five hospitals in Khartoum, Sudan. Clinical samples were screened for rubella IgM and for ≥ 6 months old infants also for IgG antibodies by ELISA. The oral fluid of IgM and/or IgG positive patients was tested for rubella RNA by reverse transcriptase PCR. RESULTS: Our findings revealed that two children (2.0%) were IgM positive and another five children (5.1%) were positive for IgG antibodies. None of the five infants of which enough oral fluid was available for RNA investigation was PCR positive. CONCLUSIONS: This study documented the presence of CRS in Sudan and highlighted the importance of rubella vaccine introduction for preventing future CRS cases in the country.

Distinctive effects of the Epstein-Barr virus family of repeats on viral latent gene promoter activity and B-lymphocyte transformation.

The Epstein-Barr virus (EBV), a human B-lymphotropic gamma herpesvirus, contains multiple repetitive sequences within its genome. A group of repetitive sequences, known as the family of repeats (FR), contains multiple binding sites for the viral trans-acting protein EBNA-1. The FR sequences are important for viral genome maintenance and for the regulation of the promoter involved in viral latent gene expression. It has been reported that a palindromic sequence with a putative secondary structure exists at the 3' end of the FR in the genome of the EBV B95-8 strain and that this palindromic sequence has been deleted from the FR of the commonly used EBV miniplasmids. For the first time, we cloned an EBV B95-8 DNA fragment containing the full-length FR, which enabled us to examine the functional difference between full-length and deleted FRs. The full-length FR, like the deleted FR, functioned as a transcriptional enhancer of the viral latent gene promoter, but that transactivation was significantly attenuated in the case of the full-length FR. No significant enhancement of replication was observed when the deleted FR was replaced with the full-length FR in an EBV miniplasmid. By contrast, when the same set of FR sequences were tested in the context of the complete EBV genome, the full-length FR resulted in more-efficient B-cell transformation than the deleted FR. We propose that the presence of the full-length FR contributes to the precise regulation of the viral latent promoter and increases the efficiency of B-cell transformation.