As doenças venéreas introduzidas pelos colonizadores poderiam ter propagado a disseminação do HIV?

O artigo do PLoS One, publicado por pesquisadores belgas no dia 01.04, utiliza diversas abordagens para investigar possíveis fatores relacionados com o processo que permitiu que poucas linhagens do vírus da imunodeficiência de símios (SIV) emergisse epidemicamente como grupos de HIV. 

O artigo High GUD Incidence in the Early 20^th Century Created a Particularly Permissive Time Window for the Origin and Initial Spread of Epidemic HIV Strains (doi/10.1371/journal.pone.0009936) argumenta que as explicações atuais não são coerentes com o período, a origem geográfica e a paucidade de linhagens epidêmicas de HIV.  Utilizam, então, uma metodologia bastante abrangente:

“Our updated molecular clock analyses established relatively narrow time intervals (roughly 1880–1940) for major SIV transfers to humans. Factors that could favor HIV emergence in this time frame may have been genital ulcer disease (GUD), resulting in high HIV-1 transmissibility (4–43%), largely exceeding parenteral transmissibility; lack of male circumcision increasing male HIV infection risk; and gender-skewed city growth increasing sexual promiscuity. We surveyed colonial medical literature reporting incidences of GUD for the relevant regions, concentrating on cities, suffering less reporting biases than rural areas. Coinciding in time with the origin of the major HIV groups, colonial cities showed intense GUD outbreaks with incidences 1.5–2.5 orders of magnitude higher than in mid 20^th century. We surveyed ethnographic literature, and concluded that male circumcision frequencies were lower in early 20^th century than nowadays, with low rates correlating spatially with the emergence of HIV groups. We developed computer simulations to model the early spread of HIV-1 group M in Kinshasa before, during and after the estimated origin of the virus, using parameters derived from the colonial literature.”

Utilizando tal abordagem, eles concluem que o fator facilitador mais provável são as doenças ulcerosas genitais (xi). 

Ilustração: The effect of selected factors on the simulated early spread of HIV for Kinshasa 1919.

Sousa, J., Müller, V., Lemey, P., & Vandamme, A. (2010). High GUD Incidence in the Early 20th Century Created a Particularly Permissive Time Window for the Origin and Initial Spread of Epidemic HIV Strains PLoS ONE, 5 (4) DOI: 10.1371/journal.pone.0009936