15 Oct 2025
15th of October 2025
Brussels, October 15th, 2025
NEAT ID Rapid Oral Abstract Presentation at EACS 2025: Results from the “MASH-1” Study.
Mpox-Related Hospitalization Higher in People Living with HIV: European MASH-1 Cohort Data Presented at EACS 2025
Data will be presented during the 20th European AIDS Conference (EACS 2025) in Paris, to reveal that people living with HIV (PLWH) are at significantly greater risk of hospitalization from mpox than PrEP users, especially when immunosuppression or low CD4 counts are present.
The data will be presented on Friday the 17th of October 2025 in session RO1 - Mpox - from prevention to clinics, between 12:30-1:30pm CEST.
Presentation title: “Mpox-related hospitalization and morbidity in people living with HIV and PrEP users: results from the European MASH-1 cohort study.”
Presentation time: 13:19-13:26
The findings come from the European MASH-1 cohort study, one of the largest multicentre, multinational datasets examining adverse mpox outcomes in key populations. The study, titled “Mpox-related hospitalisation and morbidity in people living with HIV and PrEP users,” will be presented by Dr Nicolo Girometti of Chelsea and Westminster Hospital, London, on behalf of the MASH-1 study group.
Dr Girometti explained: “The MASH-1 study, sponsored by NEAT ID, followed up 2,000 people with mpox across several European countries to fill an important knowledge gap about mpox treatment and care. This is the first study to directly compare how mpox affects two groups with similar sample representation — people living with HIV and those taking HIV prevention medication (PrEP). Both groups have comparable lifestyles and use the same types of healthcare services, so comparing them gives clinicians clearer guidance on the best ways to treat mpox patients.
· Mpox presented generally as a mild illness in this large European cohort of gay, bisexual and other men having sex with men living with HIV or on PrEP, although complications were common.
· Both low CD4 cell-count (<200/mmc) and immunosuppression (independently of HIV status) strongly predicted hospitalization due to mpox
· This is the first study to quantify the additional hospitalization risk in people living with HIV, directly compared to PrEP users
· This study highlights that targeted monitoring and healthcare resources need to be allocated for the care of GBMSM that could be at greater risk of hospitalization
Mpox was generally mild across the cohort, but complications were common, and low CD4 counts and immunosuppression—regardless of HIV status—were strong, independent predictors of hospitalization. This is the first study to quantify the increased risk of hospitalization in people living with HIV.
Contributing sites: Chelsea and Westminster (UK), Hospital Clinic Barcelona (Spain), Hospital Clinic San Carlos (Spain), Hospital Bichat (France), Hospital Vall d'Hebron (Spain), ECEE – Euroguidelines in Central and Eastern Europe (Poland), Hôpital Universitaire de la Pitié-Salpêtrière (France), Hospital Germans Trias i Pujol (Spain), Hospital Universitario La Paz (Spain)
The study is sponsored by NEAT ID and funded by the European Union under the VERDI project (101045989). (Disclaimer: Views and opinions expressed are however those of the VERDI Consortium only and do not necessarily reflect those of the European Union or the European Health and Digital Executive Agency. Neither the European Union nor the granting authority can be held responsible for them.)
Notes to editors:
1. NEAT ID's mission is to support and develop Clinical Research on Infectious Diseases and spread expertise, resources and funds. NEAT ID provides training and mobility of scientists at all levels and foster lasting research collaborations Internationally. Please visit our website for more details: https://www.NEAT-ID.org
2. Dr Nicolo Girometti is a consultant physician in HIV and sexual health at 56 Dean Street, Chelsea and Westminster Hospital (London, UK). His main research interests are around HIV prevention strategies and sexually transmitted infections prevention.
3. VERDI is an EU-funded project uniting 29 partners across the world, coordinated by the University of Padua and Penta Foundation (Italy), with scientific leadership shared with University College London. It prioritises pregnant women, children and high-risk populations in research on COVID-19 and mpox, while also focusing on preparedness for future infection outbreaks. https://verdiproject.org/
Media contact: Polly.Parks@NEAT-ID.org +44 07850 695261