Tracing the Impact of Public Health Interventions on HIV-1 Transmission in Portugal Using Molecular Epidemiology. (26th February 2019)

• Record Type: Journal Article
• Authors: Vasylyeva, Tetyana I; du Plessis, Louis; Pineda-Peña, Andrea C; Kühnert, Denise; Lemey, Philippe; Vandamme, Anne-Mieke; Gomes, Perpétua; Camacho, Ricardo J; Pybus, Oliver G; Abecasis, Ana B; Faria, Nuno R
• Is Part Of: Journal of infectious diseases. Volume 220:Number 2(2019)
• Page Start: 233
• Page End: 243
• Publication Date: 2019-02-26
• Subjects: HIV -- Portugal -- phylodynamics -- epidemiology -- reproductive number -- transmission groups -- harm reduction; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiz085
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: Background: Estimation of temporal changes in human immunodeficiency virus (HIV) transmission patterns can help to elucidate the impact of preventive strategies and public health policies. Methods: Portuguese HIV-1 subtype B and G pol genetic sequences were appended to global reference data sets to identify country-specific transmission clades. Bayesian birth-death models were used to estimate subtype-specific effective reproductive numbers (Re ). Discrete trait analysis (DTA) was used to quantify mixing among transmission groups. Results: We identified 5 subtype B Portuguese clades (26–79 sequences) and a large monophyletic subtype G Portuguese clade (236 sequences). We estimated that major shifts in HIV-1 transmission occurred around 1999 (95% Bayesian credible interval [BCI], 1998–2000) and 2000 (95% BCI, 1998–2001) for subtypes B and G, respectively. For subtype B, Re dropped from 1.91 (95% BCI, 1.73–2.09) to 0.62 (95% BCI, .52–.72). For subtype G, Re decreased from 1.49 (95% BCI, 1.39–1.59) to 0.72 (95% BCI, .63–.8). The DTA suggests that people who inject drugs (PWID) and heterosexuals were the source of most (>80%) virus lineage transitions for subtypes G and B, respectively. Conclusions: The estimated declines in Re coincide with the introduction of highly active antiretroviral therapy and the scale-up of harm reduction for PWID. Inferred transmission events across transmission groups emphasize the importance of prevention efforts for bridging populations. Abstract : Birth-death phylodynamic models uncover how human immunodeficiency virus (HIV) transmission dynamics was decelerated by harm-reduction programs in the 1990s in Portugal. After 2000, transmissions in heterosexuals and people who inject drugs were driving the Portuguese HIV-1 subtype B and G epidemic, respectively.