Reassortmentista

Reassortmentista is a term used in some contexts to denote a virus or genetic element that has emerged through reassortment of genome segments. It is a neologism formed from reassortment and the suffix -ista, and it is not widely used in English-language scientific literature. In many cases, the more common term is reassortant virus or reassortment-derived virus.

Reassortment refers to the exchange of whole genome segments between co-infecting viruses that have segmented genomes. When two distinct strains infect the same cell, their gene segments can be packaged into new virions, producing progeny with a mosaic of segments from both parental lineages. This process can generate rapid genetic shifts and new phenotypes, including altered antigenicity or host range. Reassortment is well documented in influenza A, and to a lesser extent in other segmented viruses such as rotaviruses, bunyaviruses, and arenaviruses.

The appearance of reassortment-derived viruses can have significant public health implications, because sudden combinations of segments may yield novel properties with pandemic potential or changes in virulence and transmissibility. Notable historical examples in influenza include the 1957 and 1968 pandemics and the 2009 H1N1 outbreak, all of which involved reassortment among human, swine, and avian lineages. Detection relies on genomic sequencing and phylogenetic analysis to identify segments with different evolutionary histories.

Terminology guidance suggests using reassortant virus or explicitly describing a virus that originated by reassortment, rather than relying on the less common term reassortmentista.