7.7 Integration of rubella molecular and epidemiological data

Epidemiological data should accompany viral surveillance specimens in order to increase the usefulness of the molecular information. If a virus can be identified as an importation using standard epidemiological means and the country of origin is known, this information should be provided. The information for the corresponding viral sequence must be sufficient to provide the WHO name for the sequence.

The lack of comprehensive rubella surveillance in many parts of the world has resulted in a paucity of sequences available from many areas and an absence of representative rubella sequences from other areas. Consequently, the current database does not contain sufficient geographic diversity for a comprehensive depiction of global rubella genotype distribution. Continued efforts to strengthen rubella virologic surveillance are needed, especially in those countries where little or no virologic surveillance is carried out.

Even as virologic surveillance for rubella increases and more genetic data become available, the progress towards control and elimination of rubella will likely reduce the diversity of circulating rubella genotypes. Similar to the situation with measles, analyses of circulating viruses will require sequencing methodologies that can discriminate among closely related viruses within a genotype in order to track rubella viruses of genotypes 1E, 1G, and 2B. Extended window sequencing and next-generation sequencing are covered in section 7.11.