Introduction: The first case of human immunodeficiency virus type 2 (HIV-2) seropositivity in Austria was confirmed in 1993 in a dually human immunodeficiency virus type 1 (HIV-1)- and HIV-2-infected patient from Ghana, who died in 2001. Before this investigation, no further HIV-2 infection was published.
Methods: The aim of this study was to describe HIV-2 epidemiology in Austria, using serological and molecular techniques, and to perform a sequence analysis of the circulating viral strains.
Results: Six additional cases of HIV-2 were identified from 2000 to 2009. All patients originated from high-prevalence areas. In one patient, the HIV-2 infection was revealed 11 years after initial HIV-1 diagnosis, and further analysis confirmed a dual infection.
Conclusion: The HIV-2 epidemic has its epicentre in West Africa, but sociocultural issues, especially migration, are contributing to the low but continuous worldwide spread of HIV-2. Diagnosis of HIV-2 implies a different therapeutical management to avoid treatment failure and clinical progression. Differential diagnosis of HIV-1 and HIV-2 is complicated due to antibody cross-reactivity, and paradoxical findings (e.g. declining CD4 cell count despite HIV-1 suppression) may require careful reassessment, especially in patients from endemic countries.