Sequences similar to members of the Circoviridae family of ssDNA viruses were detected in 13/123 samples (10.6%). All of the sequences aligned to circovirus or circovirus-like replicase protein sequences. The alignments ranged from 36-84% amino acid identity, and appeared to derive from the replicase genes from multiple related species (Table 1) . Circovirus-like replicase sequences have been detected in human stool, animals, and environmental samples [45] [46] [47] [48] . We detected a range of 12 to 205 circovirus-like reads per positive sample ( Table 1 ). The low sequence coverage prohibited complete genome sequence assembly but informed sequence-specific primer design, from which we were often able to recover larger continuous regions of the replicase genes by PCR and Sanger sequencing (GenBank accessions JF781513, JN837698, and see Table S2 ).