In addition to the controls, two non-control samples contained evidence of RNA virus sequence. Both samples had reads deriving from GB Virus C (GBV-C, also known as Hepatitis G Virus) and were essentially identical to GBV-C database sequences. We detected no sequences that best aligned to dsRNA viruses or to retroviruses (except for human endogenous retrovirus and contaminating MLV RT-derived sequences, see Methods).