Imperial College London


Faculty of MedicineSchool of Public Health

Honorary Research Fellow



r.baggaley Website




Praed StreetSt Mary's Campus





I am a Sir Henry Wellcome Postdoctoral Research Fellow in infectious disease epidemiology. My research involves using mathematical modelling to investigate the effects of various interventions on HIV transmission, such as antiretroviral therapy (ART), treatment of herpes simplex virus and microbicides. I am also researching the effects that coinfections such as malaria, tuberculosis, helminths and sexually transmitted infections may have on HIV transmission by enhancing HIV set-point viral load during the long asymptomatic period of infection. Related to my work on the role of ART in HIV control, I am interested in the emergence and spread of antiretroviral drug resistance through populations, particularly sub-Saharan Africa, as antiretroviral therapy coverage is scaled-up in this region.


Through my experience of mathematical modelling I have appreciated the importance of appropriate and accurate estimation of model parameters and as a result have become heavily involved in the systematic review (and meta-analysis, where appropriate) of key model parameters: HIV infectiousness and sexual behaviour.  I have been working on estimating HIV transmission risk for various modes of transmission including: HIV risk per act and HIV transmission rate among discordant couples for heterosexual sex, and risks through anal sex, oral sex, blood transfusion and needlestick injury. Most recently I have compared HIV transmission risks reported from prospective discordant couple studies (couples with one infected and one uninfected partner, followed through time to measure rate of transmission to the initially uninfected partner) for couples where the infected partner was receiving ART to those with no ART use (results in press).


Regarding behaviour, I am currently involved in a systematic review of prevalence and frequency of anal sex practice within heterosexual populations. Our reviews of HIV transmission probabilities have highlighted the high risk associated with heterosexual anal sex; therefore we need better estimation of patterns of anal sex within heterosexual populations to estimate its role in driving HIV transmission and its potential role in obscuring the true impact of some interventions (for example, does it dilute the effectiveness of vaginal microbicides?).


My other main research interest remains maternal health within developing countries. I have been estimating the potential impact of interventions such as multivitamin polypills and expanded access to family planning facilities in terms of maternal deaths averted.


I am passionate about the need for effective science communication, especially the process of developing innovative ways to convey complex ideas to different audiences: other researchers, policy makers, funders, media and the general population. I am involved with the Wellcome Trust’s public engagement activities and carried out a placement at the BBC to learn more about science broadcasting.




Silhol R, Coupland H, Baggaley R, et al., 2021, What is the burden of heterosexually-acquired HIV due to HSV-2? Global and regional model-based estimates of the proportion and number of HIV infections attributable to HSV-2 infection, Jaids: Journal of Acquired Immune Deficiency Syndromes, Vol:88, ISSN:1525-4135, Pages:19-30

Hatherell H-A, Simpson H, Baggaley RF, et al., 2021, Sustainable Surveillance of Neglected Tropical Diseases for the Post-Elimination Era, Clinical Infectious Diseases, Vol:72, ISSN:1058-4838, Pages:S210-S216

Baggaley RF, Vegvari C, Dimala CA, et al., 2021, Health economic analyses of latent tuberculosis infection screening and preventive treatment among people living with HIV in lower tuberculosis incidence settings: a systematic review, Wellcome Open Research, Vol:6, Pages:51-51

Anderson RM, Hollingsworth TD, Baggaley RF, et al., 2020, COVID-19 spread in the UK: the end of the beginning?, Lancet, Vol:396, ISSN:0140-6736, Pages:587-590

Owen BN, Baggaley R, Maheu-Giroux M, et al., 2020, Patterns and trajectories of anal intercourse practice over the life course among US women at risk of HIV, Jias (submitted)

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