Determination of Rubella virus strains associated with congenital birth defects in Uganda

Abstract

Rubella, a vaccine-preventable viral disease, is a highly contagious childhood disease caused by the rubella virus that is still prevalent in all regions except the Americas, where it has been eradicated. Rubella is a public health concern when it occurs during the first trimester of pregnancy because the virus is teratogenic, resulting in congenital rubella syndrome. Although there are no specific antiviral drugs for the treatment of rubella and congenital rubella syndrome (CRS), they can be avoided by vaccination, which is an effective tool for the elimination of rubella and congenital rubella. Rubella vaccination is the only way to prevent mothers from contracting the rubella virus. Rubella vaccination during pregnancy and getting pregnant less than four weeks after rubella vaccination is not advised because the MMR vaccine is a live virus vaccine that has been attenuated. CRS cases in this study have been identified at the Uganda Heart Institute through hospital-based sentinel surveillance since 2014. In October 2019, Uganda introduced rubella containing vaccines into its routine immunization program in the form of Measles-Rubella. The goal of this study was to characterize the rubella virus strains associated with congenital birth defects in Uganda between 2014 and 2021. Rubella RNA was observed in the sera of rubella IgM positive CRS children. This provides baseline genotype data for the purposes of monitoring rubella and CRS control strategies. Rubella-specific IgM antibodies was present in 36 sera collected from the sentinel site. Among the 36 Rubella Positive samples, there were 22 (61.1%) males and 14 (38.9%) females. The patients' ages ranged from 4 days to 8 years in all suspected CRS cases, with the majority of cases (32(88.9%) being less than a year old and the remaining 11.1% being over 1 year. The real-time reverse transcription-polymerase chain reaction was used to screen rubella positive samples. Rubella real-time polymerase chain reaction positivity was found in 6% of the 36 sera tested, revealing two distinct genotypes 2B and 1G. Among the 13 Rubella virus genotypes documented; 1E, 1G, 1J, and 2B strains are the most frequently detected. This was the first study to report on genotypes of congenital rubella syndrome discovered in Uganda. The findings of this study, as well as those of other authors, show that genotype data can be obtained from antibody positive samples. The oral fluid sample is recommended as an alternative sample for CRS confirmation because the sample collection method is less invasive, the virus titers are high and the same sample can be used for both serological testing and molecular techniques.