Molecular epidemiology of vertical human immunodeficiency virus type 1 transmission in Greece: evidence of non-B subtypes

OBJECTIVES: To investigate the subtype classification of the circulating virus strains among human immunodeficiency virus type 1 (HIV-1)-infected children in Greece. STUDY DESIGN/METHODS: Since the beginning of the acquired immunodeficiency syndrome (AIDS) epidemic in Greece in 1982, 23 children have been reported to be vertically infected with HIV-1. Blood samples were available for 19 of these children, and the C2-C4 env region was successfully amplified by nested polymerase chain reaction (PCR) for 16 subjects. HIV-1 subtype was established by the heteroduplex mobility assay (HMA) in 16 subjects and confirmed by DNA sequencing and phylogenetic analysis in 8 subjects. RESULTS: Most subjects (9; 56%) fell into subtype B. However, a substantial proportion (44%) were classified as subtypes A (3; 19%), C (1; 6%), D (1; 6%), and I (2; 12%). According to epidemiologic information, 5 of 7 children infected with non-B HIV-1 subtypes were born to Greek parents. CONCLUSION: These findings clearly suggest that non-B strains have been introduced into Greece, providing evidence that HIV epidemic in this country will probably change profile over time. In addition, subtype I was identified in 2 HIV-1-infected children, both of whom were born to Greek parents.