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Castel C, Sommen C, Strat YL, Alioum A. A multi-state Markov model using notification data to estimate HIV incidence, number of undiagnosed individuals living with HIV, and delay between infection and diagnosis: Illustration in France, 2008-2018. Stat Methods Med Res 2021; 30:2382-2398. [PMID: 34606379 DOI: 10.1177/09622802211032697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Thirty-five years since the discovery of the human immunodeficiency virus (HIV), the epidemic is still ongoing in France. To guide HIV prevention strategies and monitor their impact, it is essential to understand the dynamics of the HIV epidemic. The indicator for reporting the progress of new infections is the HIV incidence. Given that HIV is mainly transmitted by undiagnosed individuals and that earlier treatment leads to less HIV transmission, it is essential to know the number of infected people unaware of their HIV-positive status as well as the time between infection and diagnosis. Our approach is based on a non-homogeneous multi-state Markov model describing the progression of the HIV disease. We propose a penalized likelihood approach to estimate the HIV incidence curve as well as the diagnosis rates. The HIV incidence curve was approximated using cubic M-splines, while an approximation of the cross-validation criterion was used to estimate the smoothing parameter. In a simulation study, we evaluate the performance of the model for reconstructing the HIV incidence curve and diagnosis rates. The method is illustrated in the population of men who have sex with men using HIV surveillance data collected by the French Institute for Public Health Surveillance since 2004.
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Affiliation(s)
- Charlotte Castel
- Data Science Division, French Institute for Public Health Surveillance, Saint-Maurice, France.,University of Paris-Est, Champs-Sur-Marne, France
| | - Cecile Sommen
- Data Science Division, French Institute for Public Health Surveillance, Saint-Maurice, France
| | - Yann Le Strat
- Data Science Division, French Institute for Public Health Surveillance, Saint-Maurice, France
| | - Ahmadou Alioum
- Epidemiology and Biostatistics Research Center, Inserm Center U1219-Bordeaux Population Health, Bordeaux, France.,Inserm Center U1219-Bordeaux Population Health, ISPED, University of Bordeaux 2, Bordeaux, France
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Nichols BE, van der Valk M. Barriers to eliminating HIV transmission in England by 2030. LANCET PUBLIC HEALTH 2021; 6:e699-e700. [PMID: 34563279 DOI: 10.1016/s2468-2667(21)00161-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 06/23/2021] [Indexed: 11/17/2022]
Affiliation(s)
- Brooke E Nichols
- Department of Global Health, Boston University School of Public Health, Boston, MA; Health Economics and Epidemiology Research Office (HE(2)RO), Department of Internal Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa; Department of Medical Microbiology, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, Netherlands.
| | - Marc van der Valk
- Department of Internal Medicine, Division of Infectious Diseases, Amsterdam Institute for Infection and Immunity, University of Amsterdam, Amsterdam, Netherlands; Stichting HIV Monitoring, Amsterdam, Netherlands
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Brizzi F, Birrell PJ, Kirwan P, Ogaz D, Brown AE, Delpech VC, Gill ON, De Angelis D. Tracking elimination of HIV transmission in men who have sex with men in England: a modelling study. Lancet HIV 2021; 8:e440-e448. [PMID: 34118196 PMCID: PMC8238681 DOI: 10.1016/s2352-3018(21)00044-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 02/03/2021] [Accepted: 02/18/2021] [Indexed: 01/19/2023]
Abstract
BACKGROUND To manage the HIV epidemic among men who have sex with men (MSM) in England, treatment as prevention strategies based on test and treat were strengthened between 2011 and 2015, and supplemented from 2015 by scale-up of pre-exposure prophylaxis (PrEP). We examined the effect of these interventions on HIV incidence and investigated whether internationally agreed targets for HIV control and elimination of HIV transmission by 2030 might be within reach among MSM in England. METHODS We used a novel, age-stratified, CD4-staged Bayesian back-calculation model to estimate HIV incidence and undiagnosed infections among adult MSM (age ≥15 years) during the 10-year period between 2009 and 2018. The model used data on HIV and AIDS diagnoses routinely collected via the national HIV and AIDS Reporting System in England, and knowledge on the progression of HIV through CD4-defined disease stages. Estimated incidence trends were extrapolated, assuming a constant MSM population from 2018 onwards, to quantify the likelihood of achieving elimination of HIV transmission, defined as less than one newly aquired infection per 10 000 MSM per year, by 2030. FINDINGS The peak in HIV incidence in MSM in England was estimated with 80% certainty to have occurred in 2012 or 2013, at least 1 year before the observed peak in new diagnoses in 2014. Results indicated a steep decrease in the annual number of new infections among MSM, from 2770 (95% credible interval 2490-3040) in 2013 to 1740 (1500-2010) in 2015, followed by a steadier decrease from 2016, down to 854 (441-1540) infections in 2018. A decline in new infections was consistently estimated in all age groups, and was particularly marked in MSM aged 25-34 years, and slowest in those aged 45 years or older. Similar trends were estimated in the number of undiagnosed infections, with the greatest decrease after 2013 in the 25-34 years age group. Under extrapolation assumptions, we calculated a 40% probability of achieving the defined target elimination threshold by 2030. INTERPRETATION The sharp decrease in HIV incidence, estimated to have begun before the scale up of PrEP, indicates the success of strengthening treatment as prevention measures among MSM in England. To achieve the 2030 elimination threshold, targeted policies might be required to reach those aged 45 years or older, in whom incidence is decreasing at the slowest rate. FUNDING UK Medical Research Council, UK National Institute of Health Research Health Protection Unit in Behavioural Science and Evaluation, and Public Health England.
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Affiliation(s)
- Francesco Brizzi
- Medical Research Council Biostatistics Unit, University of Cambridge, Cambridge, UK
| | - Paul J Birrell
- Medical Research Council Biostatistics Unit, University of Cambridge, Cambridge, UK; National Infection Service, Public Health England, Colindale, UK
| | - Peter Kirwan
- Medical Research Council Biostatistics Unit, University of Cambridge, Cambridge, UK; National Infection Service, Public Health England, Colindale, UK
| | - Dana Ogaz
- National Infection Service, Public Health England, Colindale, UK
| | - Alison E Brown
- National Infection Service, Public Health England, Colindale, UK
| | | | - O Noel Gill
- National Infection Service, Public Health England, Colindale, UK
| | - Daniela De Angelis
- Medical Research Council Biostatistics Unit, University of Cambridge, Cambridge, UK.
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Risher KA, Cori A, Reniers G, Marston M, Calvert C, Crampin A, Dadirai T, Dube A, Gregson S, Herbst K, Lutalo T, Moorhouse L, Mtenga B, Nabukalu D, Newton R, Price AJ, Tlhajoane M, Todd J, Tomlin K, Urassa M, Vandormael A, Fraser C, Slaymaker E, Eaton JW. Age patterns of HIV incidence in eastern and southern Africa: a modelling analysis of observational population-based cohort studies. Lancet HIV 2021; 8:e429-e439. [PMID: 34197773 PMCID: PMC8258368 DOI: 10.1016/s2352-3018(21)00069-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 03/10/2021] [Accepted: 03/23/2021] [Indexed: 01/12/2023]
Abstract
BACKGROUND As the HIV epidemic in sub-Saharan Africa matures, evidence about the age distribution of new HIV infections and how this distribution has changed over the epidemic is needed to guide HIV prevention. We aimed to assess trends in age-specific HIV incidence in six population-based cohort studies in eastern and southern Africa, reporting changes in mean age at infection, age distribution of new infections, and birth cohort cumulative incidence. METHODS We used a Bayesian model to reconstruct age-specific HIV incidence from repeated observations of individuals' HIV serostatus and survival collected among population HIV cohorts in rural Malawi, South Africa, Tanzania, Uganda, and Zimbabwe, in a collaborative analysis of the ALPHA network. We modelled HIV incidence rates by age, time, and sex using smoothing splines functions. We estimated incidence trends separately by sex and study. We used estimated incidence and prevalence results for 2000-17, standardised to study population distribution, to estimate mean age at infection and proportion of new infections by age. We also estimated cumulative incidence (lifetime risk of infection) by birth cohort. FINDINGS Age-specific incidence declined at all ages, although the timing and pattern of decline varied by study. The mean age at infection was higher in men (cohort mean 27·8-34·6 years) than in women (24·8-29·6 years). Between 2000 and 2017, the mean age at infection per cohort increased slightly: 0·5 to 2·8 years among men and -0·2 to 2·5 years among women. Across studies, between 38% and 63% (cohort medians) of the infections in women were among those aged 15-24 years and between 30% and 63% of infections in men were in those aged 20-29 years. Lifetime risk of HIV declined for successive birth cohorts. INTERPRETATION HIV incidence declined in all age groups and shifted slightly to older ages. Disproportionate new HIV infections occur among women aged 15-24 years and men aged 20-29 years, supporting focused prevention in these groups. However, 40-60% of infections were outside these ages, emphasising the importance of providing appropriate HIV prevention to adults of all ages. FUNDING Bill & Melinda Gates Foundation.
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Affiliation(s)
- Kathryn A Risher
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, UK; Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK.
| | - Anne Cori
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, UK
| | - Georges Reniers
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK; Medical Research Council/Wits University Rural Public Health and Health Transitions Research Unit (Agincourt), School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Milly Marston
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Clara Calvert
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Amelia Crampin
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK; Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
| | - Tawanda Dadirai
- The Manicaland Centre for Public Health Research, Harare, Zimbabwe
| | - Albert Dube
- Malawi Epidemiology and Intervention Research Unit, Karonga, Malawi
| | - Simon Gregson
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, UK; Biomedical Research and Training Institute, Harare, Zimbabwe
| | - Kobus Herbst
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa; Department of Science and Innovation-Medical Research Council South African Population Research Infrastructure Network, Durban, South Africa
| | - Tom Lutalo
- Rakai Health Sciences Program, Kalisizo, Uganda
| | - Louisa Moorhouse
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, UK
| | - Baltazar Mtenga
- National Institute for Medical Research, Kisesa HDSS, Mwanza, Tanzania
| | | | - Robert Newton
- Medical Research Council/Uganda Virus Research Institute and London School of Hygiene & Tropical Medicine Uganda Research Unit, Entebbe, Uganda; Department of Health Sciences, University of York, York, UK
| | - Alison J Price
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Malebogo Tlhajoane
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Jim Todd
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Keith Tomlin
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Mark Urassa
- National Institute for Medical Research, Kisesa HDSS, Mwanza, Tanzania
| | - Alain Vandormael
- Africa Health Research Institute, KwaZulu-Natal, Durban, South Africa; KwaZulu-Natal Research Innovation and Sequencing Platform, UKZN, Durban, South Africa; Heidelberg Institute of Global Health, Faculty of Medicine, University of Heidelberg, Heidelberg, Germany
| | - Christophe Fraser
- Oxford Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Emma Slaymaker
- Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
| | - Jeffrey W Eaton
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London, UK; Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK
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