Presence of multiple non-B subtypes and divergent subtype B strains of HIV-1 in individuals infected after overseas deployment

Objective: To identify the genetic subtypes and characteristics of HIV-1 strains from individuals infected after overseas deployment. Patients and methods: Sixty-one HIV-l-positive individuals detected between 1986 and 1995 in the French army were included in the study. For each patient, the year and country of HIV infection are known. Genetic subtypes of HIV-1 were determined using the heteroduplex mobility assay (HMA) using ED5/ED12 as outer and ES7/ES8 as inner primers. Strains were further characterized by sequencing and phylogenetic analysis of the C2-V3 region. The amino-acid sequences corresponding to the V3 region were aligned on the basis of the subtyping results and were then compared to the consensus V3 sequences of the corresponding subtypes. Results: Among the 61 patients studied, nine became infected in France, and 52 were HIV-negative before overseas deployment but HIV-positive at their return. The majority (n = 43) deployed in Africa and a limited number of patients deployed in Asia (Cambodia, n = 5) or South America (Guyana, n = 4). The nine individuals who were not deployed overseas were all infected with subtype B strains. The majority of the other patients were infected with non-B strains; eight subtype A, 20 subtype B, 16 subtype C, one subtype D, six subtype E and one subtype F. Five of the six subtype E strains were contracted in Cambodia and one in Djibouti, and all subtype C strains were from Djibouti. Phylogenetic analysis revealed a large diversity among the different strains introduced into France. Analysis of the amino-acid sequences of the V3 loop revealed the introduction of uncommon V3-loop patterns. Conclusion: In the group of HIV-1-infected individuals that we studied and who were deployed overseas, 63.4% were infected with non-B strains. In addition, the subtype A, B and C viruses in this population were very heterogeneous. Due to the routine occurrence of international travel and deployment, the predominance of subtype B HIV-1 viruses may change in European countries. However, the possible implications on the dynamics of the HIV-1 epidemic needs further follow-up.