Abstract
Rubella Virus (RV), which causes measles-like rashes in children, puts millions of infants at risk of congenital defects across the globe. Employing phylogenetic approaches to the whole genome sequence data and E1 glycoprotein sequence data, the present study reports the substitution rates and dates of emergence of all thirteen previously described rubella genotypes, and gains important insights into the epidemiological dynamics of two geographically widely distributed genotypes 1G and 2B. The overall nucleotide substitution rate of this non-vector-borne RV is in the order of 10−3 substitutions/site/year, which is considerably higher than the substitution rates previously reported for the vector-borne alphaviruses within the same family. Currently circulating strains of RV share a common ancestor that existed within the last 150 years, with 95% Highest Posterior Density values ranging from 1868 to 1926 AD. Viral strains within the respective genotypes began diverging between the year 1930 s and 1980 s. Both genotype 1G and 2B have shown a decline in effective number of infections since 1990 s, a period during which mass immunization programs against RV were adapted across the globe. Although both genotypes showed some extent of spatial genetic structuring, the analyses also depicted an inter-continental viral dispersal. Such a viral dispersal pattern could be related to the migration of infected individuals across the regions coupled with a low coverage of MMR vaccination.
Highlights
The increasingly intercontinental movements of people, commodities, and trade undoubtedly have a significant impact on the economic growth of every nation; these movements could make any nation susceptible to infectious diseases [1]
We found a large degree of overlap in the evolutionary rate estimated from the whole genome, structural protein (SP), NSP, as well as from the partial E1 nucleotide sequences (739-bp) (Table 1)
We estimate the overall substitution rate of rubella virus (RV) to be in the order of 1023 subs/site/year, which is compatible with the rate that was previously reported for the 1E genotype of RV [21]
Summary
The increasingly intercontinental movements of people, commodities, and trade undoubtedly have a significant impact on the economic growth of every nation; these movements could make any nation susceptible to infectious diseases [1]. In today’s interconnected world, if infectious viral pathogens are still spreading in parts of the world, reappearance of these viral pathogens will be possible in other regions that once declared complete elimination [1]. In early 2000’s, the rubella virus (RV) was declared to be completely eliminated from the United States, there are increasing evidence of importation of viral genotypes from Asian and South American countries [2,3,4,5]. In non-immunized women, it can severely affect the fetus during early pregnancy, resulting in miscarriage, fetal death, or birth defects such as congenital rubella syndrome (CRS), which includes heart disease, blindness and deafness [6,7,8,9,10]. The developed world has succeeded in eliminating RV and CRS through mass vaccination, the poor coverage of vaccination in many countries in the Southeast Asia, South America and Africa regions remains a global concern [2,8,9,10,12,13,14,15,16,17,18,19,20,21]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
