Human Herpesvirus 6 (HHV-6) sequence was detected in 13/ 123 previously negative samples (10.6%). The HHV-6 positive samples had an average normalized read count of 145 HHV-6 reads per sample (range: 24-411), representing 0.002% to 0.02% of the datasets (Table 1) , and all of these reads possessed high sequence identity to the HHV-6B reference genome sequence (gi: 9633069). We generated alignments to the reference genome to investigate the depth and genomic position of the sequence coverage across the HHV-6 genome ( Figure 2) . Although the reads only constitute a relatively small fraction of each dataset, there is coverage across the entire genome and over many genes in most of the HHV-6 positive samples.