Table 4.

Phylogenetic Evaluation of Viremic, Genotype-Concordant Couples (n = 6)

Couple ID (Genotype)	Pairwise Distance Between Sequences*	P	No. of Base Pair Differences Between Partners†	P	Estimated Minimal Divergence Time‡
Couple 9 (1a)	0.059	>0.05	50	>0.05	19.2
Couple 11 (1b)	0.071	>0.05	59	>0.05	22.3
Couple 13 (1b)	0.069	>0.05	59	>0.05	22.3
Couple 14 (1a)	0.062	>0.05	53	>0.01	20.4
Couple 14§ (2b)	0.018	<0.01	17	<0.01	6.5
Couple 15 (1a)	0.044	<0.01	38	<0.01	14.6
Couple 17 (1a)	0.076	>0.05	64	>0.05	24.6
Couple 17 (1b)	0.018	<0.01	16	<0.01	6.2

Three of the six couples had strong evidence of infection with the same HCV isolate (in bold).

^*In the reference sets for subtypes 1a and 1b, the mean pairwise distance was 0.618 ± 0.0006 (SD) (<1.65 SD = 0.052) for subtype 1a and 0.071 ± 0.007 (<1.54 SD = 0.059) for subtype 1b.

^†In the reference sets for subtypes 1a and 1b, the mean number of base pair differences was 52.33 ± 5.33 (<1.65 SD = 43.5) for subtype 1a and 59.53 ± 5.79 (<1.65 SD = 46.2) for subtype 1b sequences.

^‡Minimal divergence time based on estimated divergence rate of 2.6 nucleotide positions per year for the target region analyzed.

^§Significance was calculated relative to the subtype 1a distribution because an adequate background distribution could not be established with the publicly available subtype 2b sequences. These values are also significant when compared with the subtype 1a distribution.