Post-exposure prophylaxis following consented sexual exposure: impact of national recommendations on user profile, drug regimens and estimates of averted HIV infections.

OBJECTIVES: The aim of the study was to describe the characteristics, impact and outreach of post-exposure prophylaxis (PEP) for sexual exposure in Brazil. METHODS: We used secondary data from the Brazilian Ministry of Health to describe the impact of national guidelines on the frequency of prescription, user profile and antiretroviral regimens. We also estimated the number of potentially averted HIV infections attributable to PEP for consented sexual exposure between 2009 and 2017. RESULTS: A total of 260 457 PEP regimens were prescribed to individuals ≥ 14 years old; 104 613 (40.2%) were prescribed for consented sexual exposure, with an increasing frequency since 2011. Drugs used in PEP regimens underwent significant modifications during the period, reflecting national recommendations. We estimated that there were up to 3138 potentially averted HIV infections attributable to PEP for consented sexual exposure between 2009 and 2017. CONCLUSIONS: In the context of a combined HIV prevention strategy, PEP is still an essential tool for individuals for whom other methods are contraindicated or fail to be applied.

The evolution of South American endemic canids: a history of rapid diversification and morphological parallelism.

The origin of endemic South American canid fauna has been traditionally linked with the rise of the Isthmus of Panama, suggesting that diversification of the dog fauna on this continent occurred very rapidly. Nevertheless, despite its obvious biogeographic appeal, the tempo of Canid evolution in South America has never been studied thoroughly. This issue can be suitably tackled with the inference of a molecular timescale. In this study, using a relaxed molecular clock method, we estimated that the most recent common ancestor of South American canids lived around 4 Ma, whereas all other splits within the clade occurred after the rise of the Panamanian land bridge. We suggest that the early diversification of the ancestors of the two main lineages of South American canids may have occurred in North America, before the Great American Interchange. Moreover, a concatenated morphological and molecular analysis put some extinct canid species well within the South American radiation, and shows that the dental adaptations to hypercarnivory evolved only once in the South American clade.