GABBR1 and infection: Within the mixed infection population, the frequencies of the combinations were as follows: gB1/gB2 (n = 19), gB1/gB3 (n = 27), gB1/gB4 (n = 7), gB2/gB3 (n = 11), gB2/gB4 (n = 4), gB3/gB4 (n = 7), a mixture of three gB genotypes (n = 35) and all four genotypes (n = 8).