Imperial College London

ProfessorTimothyHallett

Faculty of MedicineSchool of Public Health

Professor of Global Health
 
 
 
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Contact

 

+44 (0)20 7594 1150timothy.hallett

 
 
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Location

 

Norfolk PlaceSt Mary's Campus

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Summary

 

Publications

Publication Type
Year
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189 results found

Anderson S-J, Garnett GP, Enstone J, Hallett TBet al., 2018, The importance of local epidemic conditions in monitoring progress towards HIV epidemic control in Kenya: a modelling study., J Int AIDS Soc, Vol: 21

INTRODUCTION: Setting and monitoring progress towards targets for HIV control is critical in ensuring responsive programmes. Here, we explore how to apply targets for reduction in HIV incidence to local settings and which indicators give the strongest signal of a change in incidence in the population and are therefore most important to monitor. METHODS: We use location-specific HIV transmission models, tailored to the epidemics in the counties and major cities in Kenya, to project a wide range of plausible future epidemic trajectories through varying behaviours, treatment coverage and prevention interventions. We look at the change in incidence across modelled scenarios in each location between 2015 and 2030 to inform local target setting. We also simulate the measurement of a library of potential indicators and assess which are most strongly associated with a change in incidence. RESULTS: Considerable variation was observed in the trajectory of the local epidemics under the plausible scenarios defined (only 10 of 48 locations saw a median reduction in incidence of greater than or equal to an 80% target by 2030). Indicators that provide strong signals in certain epidemic types may not perform consistently well in settings with different epidemiological features. Predicting changes in incidence is more challenging in advanced generalized epidemics compared to concentrated epidemics where changes in high-risk sub-populations track more closely to the population as a whole. Many indicators demonstrate only limited association with incidence (such as "condom use" or "pre-exposure prophylaxis coverage"). This is because many other factors (low effectiveness, impact of other interventions, countervailing changes in risk behaviours, etc.) can confound the relationship between interventions and their ultimate long-term impact, especially for an intervention with low expected coverage. The population prevalence of viral suppression shows the most consiste

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Ghys PD, Williams BG, Over M, Hallett TB, Godfrey-Faussett Pet al., 2018, Epidemiological metrics and benchmarks for a transition in the HIV epidemic, PLOS MEDICINE, Vol: 15, ISSN: 1549-1676

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Fu H, Lin H-H, Hallett TB, Arinaminpathy Net al., 2018, Modelling the effect of discontinuing universal Bacillus Calmette-Guerin vaccination in an intermediate tuberculosis burden setting, VACCINE, Vol: 36, Pages: 5902-5909, ISSN: 0264-410X

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McGillen JB, Stover J, Klein DJ, Xaba S, Ncube G, Mhangara M, Chipendo GN, Taramusi I, Beacroft L, Hallett TB, Odawo P, Manzou R, Korenromp ELet al., 2018, The emerging health impact of voluntary medical male circumcision in Zimbabwe: An evaluation using three epidemiological models, PLOS ONE, Vol: 13, ISSN: 1932-6203

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Olney JJ, Eaton JW, Braitstein P, Hogan JW, Hallett TBet al., 2018, Optimal timing of HIV home-based counselling and testing rounds in Western Kenya, JOURNAL OF THE INTERNATIONAL AIDS SOCIETY, Vol: 21, ISSN: 1758-2652

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Meyer-Rath G, McGillen JB, Cuadros DF, Hallett TB, Bhatt S, Wabiri N, Tanser F, Rehle Tet al., 2018, Targeting the right interventions to the right people and places: the role of geospatial analysis in HIV program planning, AIDS, Vol: 32, Pages: 957-963, ISSN: 0269-9370

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Hecht R, Hiebert L, Spearman WC, Sonderup M, Guthrie T, Hallett TB, Nayagam S, Razavi H, Soe-Lin S, Vilakazi-Nhlapo K, Pillay Y, Resch Set al., 2018, The investment case for hepatitis B and C in South Africa: adaptation and innovation in policy analysis for disease program scale-up, HEALTH POLICY AND PLANNING, Vol: 33, Pages: 528-538, ISSN: 0268-1080

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Smit M, Olney J, Ford NP, Vitoria M, Gregson S, Vassall A, Hallett TBet al., 2018, The growing burden of noncommunicable disease among persons living with HIV in Zimbabwe, AIDS, Vol: 32, Pages: 773-782, ISSN: 0269-9370

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Anderson S-J, Ghys PD, Ombam R, Hallett TBet al., 2018, Frontloading HIV financing maximizes the achievable impact of HIV prevention, JOURNAL OF THE INTERNATIONAL AIDS SOCIETY, Vol: 21, ISSN: 1758-2652

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Phillips AN, Cambiano V, Nakagawa F, Revill P, Jordan MR, Hallett TB, Doherty M, De Luca A, Lundgren JD, Mhangara M, Apollo T, Mellors J, Nichols B, Parikh U, Pillay D, de Wit TR, Sigaloff K, Havlir D, Kuritzkes DR, Pozniak A, van de Vijver D, Vitoria M, Wainberg MA, Raizes E, Bertagnolio Set al., 2018, Cost-effectiveness of public-health policy options in the presence of pretreatment NNRTI drug resistance in sub-Saharan Africa: a modelling study, LANCET HIV, Vol: 5, Pages: E146-E154, ISSN: 2352-3018

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Smit M, van Zoest RA, Nichols BE, Vaartjes I, Smit C, van der Valk M, van Sighem A, Wit FW, Hallett TB, Reiss Pet al., 2018, Cardiovascular Disease Prevention Policy in Human Immunodeficiency Virus: Recommendations From a Modeling Study, CLINICAL INFECTIOUS DISEASES, Vol: 66, Pages: 743-750, ISSN: 1058-4838

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McRobie E, Matovu F, Nanyiti A, Nonvignon J, Abankwah DNY, Case KK, Hallett TB, Hanefeld J, Conteh Let al., 2018, National responses to global health targets: exploring policy transfer in the context of the UNAIDS '90-90-90' treatment targets in Ghana and Uganda, HEALTH POLICY AND PLANNING, Vol: 33, Pages: 17-33, ISSN: 0268-1080

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Kumi Smith M, Jewell BL, Hallett TB, Cohen MSet al., 2018, Treatment of HIV for the Prevention of Transmission in Discordant Couples and at the Population Level., Adv Exp Med Biol, Vol: 1075, Pages: 125-162, ISSN: 0065-2598

The scientific breakthrough proving that antiretroviral therapy (ART) can halt heterosexual HIV transmission came in the form of a landmark clinical trial conducted among serodiscordant couples. Study findings immediately informed global recommendations for the use of treatment as prevention in serodiscordant couples. The extent to which these findings are generalizable to other key populations or to groups exposed to HIV through nonsexual transmission routes (i.e., anal intercourse or unsafe injection of drugs) has since driven a large body of research. This review explores the history of HIV research in serodiscordant couples, the implications for management of couples, subsequent research on treatment as prevention in other key populations, and challenges in community implementation of these strategies.

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Anderson S-J, Ghys PD, Ombam R, Hallett TBet al., 2017, HIV prevention where it is needed most: comparison of strategies for the geographical allocation of interventions, JOURNAL OF THE INTERNATIONAL AIDS SOCIETY, Vol: 20, ISSN: 1758-2652

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McGillen JB, Sharp A, Honermann B, Millett G, Collins C, Hallett TBet al., 2017, Consequences of a changing US strategy in the global HIV investment landscape, AIDS, Vol: 31, Pages: F19-F23, ISSN: 0269-9370

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Nayagam S, Sicuri E, Lemoine M, Easterbrook P, Conteh L, Hallett TB, Thursz Met al., 2017, Economic evaluations of HBV testing and treatment strategies and applicability to low and middle-income countries, BMC INFECTIOUS DISEASES, Vol: 17, Pages: 107-116, ISSN: 1471-2334

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Smit M, Cassidy R, Cozzi-Lepri A, Quiros-Roldan E, Girardi E, Mammone A, Antinori A, Saracino A, Bai F, Rusconi S, Magnani G, Castelli F, Hsue P, Monforte AD, Hallett TBet al., 2017, Projections of non-communicable disease and health care costs among HIV-positive persons in Italy and the USA: A modelling study, PLOS ONE, Vol: 12, ISSN: 1932-6203

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Gregson S, Mugurungi O, Eaton J, Takaruza A, Rhead R, Maswera R, Mutsvangwa J, Mayini J, Skovdal M, Schaefer R, Hallett T, Sherr L, Munyati S, Mason P, Campbell C, Garnett GP, Nyamukapa CAet al., 2017, Documenting and explaining the HIV decline in east Zimbabwe: the Manicaland General Population Cohort, BMJ OPEN, Vol: 7, ISSN: 2044-6055

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Mangal TD, 2017, Joint estimation of CD4(+) cell progression and survival in untreated individuals with HIV-1 infection, AIDS, Vol: 31, Pages: 1073-1082, ISSN: 0269-9370

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Birger RB, Thuy L, Kouyos RD, Grenfell BT, Hallett TBet al., 2017, The impact of HCV therapy in a high HIV-HCV prevalence population: A modeling study on people who inject drugs in Ho Chi Minh City, Vietnam, PLOS ONE, Vol: 12, ISSN: 1932-6203

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Cremin I, McKinnon L, Kimani J, Cherutich P, Gakii G, Muriuki F, Kripke K, Hecht R, Kiragu M, Smith J, Hinsley W, Gelmon L, Hallett TBet al., 2017, PrEP for key populations in combination HIV prevention in Nairobi: a mathematical modelling study, LANCET HIV, Vol: 4, Pages: E214-E222, ISSN: 2352-3018

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Alsallaq RA, Buttolph J, Cleland CM, Hallett T, Inwani I, Agot K, Kurth AEet al., 2017, The potential impact and cost of focusing HIV prevention on young women and men: A modeling analysis in western Kenya, PLOS ONE, Vol: 12, ISSN: 1932-6203

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Smith JA, Heffron R, Butler AR, Celum C, Baeten JM, Hallett TBet al., 2017, Could misreporting of condom use explain the observed association between injectable hormonal contraceptives and HIV acquisition risk, CONTRACEPTION, Vol: 95, Pages: 424-430, ISSN: 0010-7824

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Case KK, Gregson S, Mahy M, Ghys PD, Hallett TBet al., 2017, Editorial: methodological developments in the Joint United Nations Programme on HIV/AIDS estimates, AIDS, Vol: 31, Pages: S1-S4, ISSN: 0269-9370

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Wilson KC, Mhangara M, Dzangare J, Eaton JW, Hallett TB, Mugurungi O, Gregson Set al., 2017, Does nonlocal women's attendance at antenatal clinics distort HIV prevalence surveillance estimates in pregnant women in Zimbabwe?, AIDS, Vol: 31, Pages: S95-S102, ISSN: 0269-9370

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Buttolph J, Inwani I, Agot K, Cleland CM, Cherutich P, Kiarie JN, Osoti A, Celum CL, Baeten JM, Nduati R, Kinuthia J, Hallett TB, Alsallaq R, Kurth AEet al., 2017, Gender-Specific Combination HIV Prevention for Youth in High-Burden Settings: The MP3 Youth Observational Pilot Study Protocol, JMIR RESEARCH PROTOCOLS, Vol: 6, Pages: 96-111, ISSN: 1929-0748

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Elmes J, Skovdal M, Nhongo K, Ward H, Campbell C, Hallett TB, Nyamukapa C, White PJ, Gregson Set al., 2017, A reconfiguration of the sex trade: How social and structural changes in eastern Zimbabwe left women involved in sex work and transactional sex more vulnerable, PLOS ONE, Vol: 12, ISSN: 1932-6203

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McGillen JB, Anderson S-J, Hallett TB, 2017, Introducing optimism to models of resource allocation to reduce HIV incidence Reply, LANCET HIV, Vol: 4, Pages: E12-E12, ISSN: 2352-3018

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Nayagam S, Conteh L, Sicuri E, Shimakawa Y, Lemoine M, Hallett TB, Thursz Met al., 2017, Community-based screening and treatment for chronic hepatitis B in sub-Saharan Africa Reply, LANCET GLOBAL HEALTH, Vol: 5, Pages: E35-E35, ISSN: 2214-109X

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Nayagam S, Thursz M, Sicuri E, Conteh L, Wiktor S, Low-Beer D, Hallett TBet al., 2016, Requirements for global elimination of hepatitis B: a modelling study, LANCET INFECTIOUS DISEASES, Vol: 16, Pages: 1399-1408, ISSN: 1473-3099

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