HIV-2 infection throughout the world. A geographical perspective

Area of Science:

• Epidemiology
• Virology
• Public Health

Background:

• The precise geographical distribution and origins of Human Immunodeficiency Virus type 2 (HIV-2) remain incompletely understood.
• Evidence suggests initial infection foci emerged in West African countries like Guinea-Bissau, Angola, and Mozambique during the 1970s.

Purpose of the Study:

• To explore the origins and differentiation of the geographical pattern of HIV-2 distribution.
• To understand the factors influencing the spread and limited epidemic potential of HIV-2.

Main Methods:

• Speculative analysis based on historical and epidemiological evidence.
• Tracing the movement of populations and the virus following decolonization and economic changes.

Main Results:

• HIV-2 likely originated in West Africa, spreading through migration post-decolonization to associated countries including Portugal, India, and Brazil.
• The Ivory Coast saw an HIV-2 focus emerge linked to socioeconomic shifts, with further dispersion via migration.
• Despite its spread within and beyond Africa, HIV-2 has not caused major epidemics due to limited infectivity and specific social/epidemiological factors.

Conclusions:

• HIV-2's geographical pattern is linked to historical events like decolonization and economic changes, influencing population movements.
• The virus's limited infectivity and the nature of social and epidemiological systems prevent sustained epidemic transmission outside of initial foci.
• Human movements continue to diversify, but HIV-2's low epidemic potential suggests contained circulation rather than widespread outbreaks.