Increasing Frequency and Transmission of HIV-1 Non-B Subtypes Among Men Who Have Sex With Men in the Swiss HIV Cohort Study. (14th July 2021)

• Record Type: Journal Article
• Authors: Duran Ramirez, Jessy J; Ballouz, Tala; Nguyen, Huyen; Kusejko, Katharina; Chaudron, Sandra E; Huber, Michael; Hirsch, Hans H; Perreau, Matthieu; Ramette, Alban; Yerly, Sabine; Cavassini, Matthias; Stöckle, Marcel; Furrer, Hansjakob; Vernazza, Pietro; Bernasconi, Enos; Günthard, Huldrych F; Kouyos, Roger D
• Is Part Of: Journal of infectious diseases. Volume 225:Number 2(2022)
• Page Start: 306
• Page End: 316
• Publication Date: 2021-07-14
• Subjects: HIV-1 -- transmission cluster -- non-B subtypes -- MSM -- molecular epidemiology -- phylogeny; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiab360
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: Background: In Switzerland, HIV-1 transmission among men who have sex with men (MSM) has been dominated by subtype B, whilst non-B subtypes are commonly attributed to infections acquired abroad among heterosexuals. Here, we evaluated the temporal trends of non-B subtypes and the characteristics of molecular transmission clusters (MTCs) among MSM. Methods: Sociodemographic and clinical data and partial pol sequences were obtained from participants enrolled in the Swiss HIV Cohort Study. For non-B subtypes, maximum likelihood trees were constructed, from which Swiss MTCs were identified and analyzed by transmission group. Results: Non-B subtypes were identified in 8.1% (416/5116) of MSM participants. CRF01_AE was the most prevalent strain (3.5%), followed by subtype A (1.2%), F (1.1%), CRF02_AG (1.1%), C (0.9%), and G (0.3%). Between 1990 and 2019, an increase in the proportion of newly diagnosed individuals (0/123 [0%] to 11/32 [34%]) with non-B subtypes in MSM was found. Across all non-B subtypes, the majority of MSM MTCs were European. Larger MTCs were observed for MSM than heterosexuals. Conclusions: We found a substantial increase in HIV-1 non-B subtypes among MSM in Switzerland and the occurrence of large MTCs, highlighting the importance of molecular surveillance in guiding public health strategies targeting the HIV-1 epidemic. Abstract : The proportion of MSM with newly diagnosed HIV-1 non-B subtypes has strongly increased since 1990, reaching 34% of all MSM diagnosed in 2019. This is partly due to ongoing local transmission in this population, as evidenced by large transmission clusters.