Imperial College London


Faculty of MedicineSchool of Public Health

Professor of Global Health



+44 (0)20 7594 1150timothy.hallett




Norfolk PlaceSt Mary's Campus






BibTex format

author = {Sarah-Jane, A and Garnett, G and Enstone, J and Hallett, T},
doi = {10.1002/jia2.25203},
journal = {Journal of the International AIDS Society},
title = {The importance of local epidemic conditions in monitoring progress towards HIV epidemic control in Kenya: a modelling study},
url = {},
volume = {21},
year = {2018}

RIS format (EndNote, RefMan)

AB - IntroductionSetting 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.MethodsWe use locationspecific 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.ResultsConsiderable 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 highrisk subpopulations track more closely to the population as a whole. Many indicators demonstrate only limited association with incidence (such as “condom use” or “preexposure 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 longterm impact, especially for an intervention with low expected coverage. The population prevalence of viral suppression shows the most consistent a
AU - Sarah-Jane,A
AU - Garnett,G
AU - Enstone,J
AU - Hallett,T
DO - 10.1002/jia2.25203
PY - 2018///
SN - 1758-2652
TI - The importance of local epidemic conditions in monitoring progress towards HIV epidemic control in Kenya: a modelling study
T2 - Journal of the International AIDS Society
UR -
UR -
VL - 21
ER -