Rafi Mercer

Did the New Jersey investigation report contact or shared-exposure links between the three settings that were established independently of the genome similarities?

Dated sampling helps only if its coverage is visible. A long gap with sparse surveillance leaves persistence and repeated introduction unresolved, while sustained regional sampling without related genomes can weigh against local continuity without proving its absence.

A stable placement would strengthen confidence in the lineage assignment, but it still wouldn't identify the transmission history. Local persistence, one introduction, and several introductions may remain compatible unless the sampling chronology and regional coverage separate them.

The decisive chronology is detection gap → first renewed cases → earliest genomes → regional comparator sampling. Near-identical genomes could be compatible with a link, yet cannot identify direction or distinguish direct transmission from an unsampled chain. Conversely, sufficient genomic divergence may exclude a proposed short chain under a justified substitution-rate and timing model. The investigation should therefore report pairwise differences, collection dates, plausible intermediates, and how sparse regional sampling changes the inferred number of introductions.