Imperial College London

DrRebeccaBaggaley

Faculty of MedicineSchool of Public Health

Honorary Research Fellow
 
 
 
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Contact

 

r.baggaley Website

 
 
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Location

 

Praed StreetSt Mary's Campus

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Summary

 

Publications

Publication Type
Year
to

64 results found

Silhol R, Coupland H, Baggaley R, Miller L, Staadegaard L, Gottlieb S, Stannah J, Turner K, Vickerman P, Hayes R, Mayaud P, Looker K, Boily M-Cet 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, Pages: 19-30, ISSN: 1525-4135

Background: Biological and epidemiological evidence suggest that herpes simplex virus type 2 (HSV-2) elevates HIV acquisition and transmission risk. We improved previous estimates of the contribution of HSV-2 to HIV infections by using a dynamic-transmission model.Setting: WHO regions.Methods: We developed a mathematical model of HSV-2/HIV transmission among 15-49-year-old heterosexual, non-drug-injecting populations, calibrated using region-specific demographic and HSV-2/HIV epidemiological data. We derived global and regional estimates of the contribution of HSV-2 to HIV infection over ten years (the transmission population-attributable fraction, tPAF) under three additive scenarios, assuming: (1) HSV-2 only increases HIV acquisition (“conservative”); (2) HSV-2 also increases HIV transmission (“liberal”); (3) HIV/ART (antiretroviral therapy) also modifies HSV-2 transmission and HSV-2 decreases ART effect on HIV transmission ("fully liberal”).Results: Under the conservative scenario, the predicted tPAF was 37.3% (95% uncertainty interval 33.4-43.2%) and an estimated 5.6 (4.5-7.0) million incident heterosexual HIV infections were due to HSV-2 globally over 2009-2018. The contribution of HSV-2 to HIV infections was largest for the African region (tPAF=42.6% (38.0-51.2%)), and lowest for the European region (tPAF=11.2% (7.9-13.8%)). The tPAF was higher among female sex-workers, their clients, and older populations, reflecting their higher HSV-2 prevalence. The tPAF was ∼50% and 1.3-2.4-fold higher for the liberal/fully liberal than the conservative scenario across regions.Conclusion: HSV-2 may have contributed to at least 37% of incident HIV infections in the last decade worldwide, and even more in Africa, and may continue to do so despite increased ART access unless future improved HSV-2 control measures, such as vaccines, become available.

Journal article

Hatherell H-A, Simpson H, Baggaley RF, Hollingsworth TD, Pullan RLet al., 2021, Sustainable Surveillance of Neglected Tropical Diseases for the Post-Elimination Era, CLINICAL INFECTIOUS DISEASES, Vol: 72, Pages: S210-S216, ISSN: 1058-4838

Journal article

Baggaley RF, Vegvari C, Dimala CA, Lipman M, Miller RF, Brown J, Degtyareva S, White HA, Hollingsworth TD, Pareek Met 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

<ns7:p><ns7:bold>Introduction: </ns7:bold>In lower tuberculosis (TB) incidence countries (&lt;100 cases/100,000/year), screening and preventive treatment (PT) for latent TB infection (LTBI) among people living with HIV (PLWH) is often recommended, yet guidelines advising which groups to prioritise for screening can be contradictory and implementation patchy. Evidence of LTBI screening cost-effectiveness may improve uptake and health outcomes at reasonable cost.</ns7:p><ns7:p> <ns7:bold>Methods: </ns7:bold>Our systematic review assessed cost-effectiveness estimates of LTBI screening/PT strategies among PLWH in lower TB incidence countries to identify model-driving inputs and methodological differences. Databases were searched 1980-2020. Studies including health economic evaluation of LTBI screening of PLWH in lower TB incidence countries (&lt;100 cases/100,000/year) were included. Study quality was assessed using the CHEERS checklist.</ns7:p><ns7:p> <ns7:bold>Results: </ns7:bold>Of 2,644 articles screened, nine studies were included. Cost-effectiveness estimates of LTBI screening/PT for PLWH varied widely, with universal screening/PT found highly cost-effective by some studies, while only targeting to high-risk groups (such as those from mid/high TB incidence countries) deemed cost-effective by others. Cost-effectiveness of strategies screening all PLWH from studies published in the past five years varied from US$2828 to US$144,929/quality-adjusted life-year gained (2018 prices). Study quality varied, with inconsistent reporting of methods and results limiting comparability of studies. Cost-effectiveness varied markedly by screening guideline, with British HIV Association guidelines more cost-effective than NICE guidelines in the UK.</ns7:p><ns7:p> <ns7:bold>Discussion: </ns7:bold>Cost-effectiveness studies of LTBI screening/PT for PLWH in lower TB incidence settings are

Journal article

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

Journal article

Owen BN, Baggaley R, Maheu-Giroux M, Elmes J, Adimora A, Ramirez C, Edmonds A, Sosanya K, Taylor T, Plankey M, Cederbaum J, Seidman D, Weber K, Golub E, Sheth A, Bolivar H, Konkle-PArker D, Boily M-Cet al., 2020, Patterns and trajectories of anal intercourse practice over the life course among US women at risk of HIV, JIAS (submitted)

Journal article

Baggaley RF, Hollingsworth TD, 2020, How universal does universal test and treat have to be?, LANCET HIV, Vol: 7, Pages: E306-E308, ISSN: 2352-3018

Journal article

Owen BN, Maheu-Giroux M, Matse S, Mnisi Z, Baral S, Ketende SC, Baggaley RF, Boily M-Cet al., 2020, Prevalence and correlates of anal intercourse among female sex workers in eSwatini (vol 15, e0228849, 2020), PLOS ONE, Vol: 15, ISSN: 1932-6203

Journal article

Owen BN, Baggaley RF, Elmes J, Harvey A, Shubber Z, Butler AR, Silhol R, Anton P, Shacklett B, van der Straten A, Boily MCet al., 2020, What proportion of female sex workers practise anal intercourse and how frequently? A systematic review and meta-analysis, AIDS and Behavior, Vol: 24, Pages: 697-713, ISSN: 1090-7165

HIV is more efficiently acquired during receptive anal intercourse (AI) compared to vaginal intercourse (VI) and may contribute substantially to female sex workers’ (FSW) high HIV burden. We aim to determine how common and frequent AI is among FSW globally. We searched PubMed, Embase and PsycINFO for studies reporting the proportion of FSW practising AI (prevalence) and/or the number of AI acts (frequency) worldwide from 01/1980 to 10/2018. We assessed the influence of participant and study characteristics on AI prevalence (e.g. continent, study year and interview method) through sub-group analysis. Of 15,830 identified studies, 131 were included. Nearly all (N = 128) reported AI prevalence and few frequency (N = 13), over various recall periods. Most studies used face-to-face interviews (N = 111). Pooled prevalences varied little by recall period (lifetime: 15.7% 95%CI 12.2–19.3%, N = 30, I 2 = 99%; past month: 16.2% 95%CI 10.8–21.6%, N = 18, I 2 = 99%). The pooled proportion of FSW reporting < 100% condom use tended to be non-significantly higher during AI compared to during VI (e.g. any unprotected VI: 19.1% 95%CI 1.7–36.4, N = 5 and any unprotected AI: 46.4% 95%CI 9.1–83.6, N = 5 in the past week). Across all study participants, between 2.4 and 15.9% (N = 6) of all intercourse acts (AI and VI) were anal. Neither AI prevalence nor frequency varied substantially by any participant or study characteristics. Although varied, AI among FSW is generally common, inconsistently protected with condoms and practiced sufficiently frequently to contribute substantially to HIV acquisition in this risk group. Interventions to address barriers to condom use are needed.

Journal article

Owen B, Maheu-Giroux M, Matse S, Mnisi Z, Baral S, Ketende S, Baggaley R, Boily M-Cet al., 2020, Prevalence and correlates of anal intercourse among female sex workers in eSwatini, PLoS One, Vol: 15, ISSN: 1932-6203

IntroductionAs HIV is very effectively acquired during condomless receptive anal intercourse (AI) with serodiscordant and viremic partners, the practice could contribute to the high prevalence among female sex workers (FSW) in eSwatini (formerly known as Swaziland). We aim to estimate the proportion reporting AI (AI prevalence) among Swazi FSW and to identify the correlates of AI practice in order to better inform HIV prevention interventions among this population.MethodsUsing respondent-driven sampling (RDS), 325 Swazi FSW were recruited in 2011. We estimated the prevalence of AI and AI with inconsistent condom use in the past month with any partner type, and inconsistent condom use during AI and vaginal intercourse (VI) by partner type. Univariate and multivariable logistic regression models were used to identify behavioural and structural correlates associated with AI and AI with inconsistent condom use.ResultsRDS-adjusted prevalence of AI and AI with inconsistent condom use was high, at 44%[95% confidence interval (95%CI):35–53%]) and 34%[95%CI:26–42%], respectively and did not vary by partner type. HIV prevalence was high in this sample of FSW (70%), but knowledge that AI increases HIV acquisition risk low, with only 10% identifying AI as the riskiest sex act. Those who reported AI were more likely to be better educated (adjusted odds ratio(aOR) = 1.92[95%CI:1.03–3.57]), to have grown up in rural areas (aOR = 1.90[95%CI:1.09–3.32]), have fewer new clients in the past month (aOR = 0.33[95%CI:0.16–0.68]), and for last sex with clients to be condomless (aOR = 2.09[95%CI:1.07–4.08]). Although FSW reporting AI in past month were more likely to have been raped (aOR = 1.95[95%CI:1.05–3.65]) and harassed because of being a sex worker (aOR = 2.09[95%CI:1.16–3.74]), they were also less likely to have ever been blackmailed (aOR = 0.50[95%CI:0.25–0.98]) or been afraid to walk in public places (aOR = 0.46[95%CI:0.25&ndas

Journal article

Stannah J, Silhol R, Elmes J, Owen B, Shacklett BL, Anton P, McGowan I, van der Straten A, Dimitrov D, Baggaley RF, Boily M-Cet al., 2019, Increases in HIV incidence following receptive anal intercourse among women: A systematic review and meta-analysis., AIDS and Behavior, Vol: 24, Pages: 667-681, ISSN: 1090-7165

Receptive anal intercourse (RAI) carries a greater per-act risk of HIV acquisition than receptive vaginal intercourse (RVI) and may influence HIV epidemics driven by heterosexual sex. This systematic review explores the association between RAI and incident HIV among women, globally. We searched Embase and Medline through September 2018 for longitudinal studies reporting crude (cRR) or adjusted (aRR) relative risks of HIV acquisition by RAI practice among women. Of 27,563 articles identified, 17 eligible studies were included. We pooled independent study estimates using random-effects models. Women reporting RAI were more likely to acquire HIV than women not reporting RAI (pooled cRR = 1.56 95% CI 1.03-2.38, N = 18, I2 = 72%; pooled aRR = 2.23, 1.01-4.92, N = 5, I2 = 70%). In subgroup analyses the association was lower for women in Africa (pooled cRR = 1.16, N = 13, I2 = 21%) than outside Africa (pooled cRR = 4.10, N = 5, I2 = 79%) and for high-risk (pooled aRR = 1.69, N = 4, I2 = 63%) than general-risk women (pooled aRR = 8.50, N = 1). Interview method slightly influenced cRR estimates (p value = 0.04). In leave-one-out sensitivity analyses pooled estimates were generally robust to removing individual study estimates. Main limitations included poor exposure definition, incomplete adjustment for confounders, particularly condom use, and use of non-confidential interview methods. More and better data are needed to explain differences in risk by world region and risk population. Women require better counselling and greater choice in prevention modalities that are effective during RVI and RAI.

Journal article

Pareek M, Eborall HC, Wobi F, Ellis KS, Kontopantelis E, Zhang F, Baggaley R, Hollingsworth TD, Baines D, Patel H, Haldar P, Patel M, Stephenson I, Browne I, Gill P, Kapur R, Farooqi A, Abubakar I, Griffiths Cet al., 2019, Community-based testing of migrants for infectious diseases (COMBAT-ID): impact, acceptability and cost-effectiveness of identifying infectious diseases among migrants in primary care: protocol for an interrupted time-series, qualitative and health economic analysis, BMJ Open, Vol: 9, ISSN: 2044-6055

Background Migration is a major global driver of population change. Certain migrants may be at increased risk of infectious diseases, including tuberculosis (TB), HIV, hepatitis B and hepatitis C, and have poorer outcomes. Early diagnosis and management of these infections can reduce morbidity, mortality and onward transmission and is supported by national guidelines. To date, screening initiatives have been sporadic and focused on individual diseases; systematic routine testing of migrant groups for multiple infections is rarely undertaken and its impact is unknown. We describe the protocol for the evaluation of acceptability, effectiveness and cost-effectiveness of an integrated approach to screening migrants for a range of infectious diseases in primary care.Methods and analysis We will conduct a mixed-methods study which includes an observational cohort with interrupted time-series analysis before and after the introduction of routine screening of migrants for infectious diseases (latent TB, HIV, hepatitis B and hepatitis C) when first registering with primary care within Leicester, UK. We will assess trends in the monthly number and rate of testing and diagnosis for latent TB, HIV, hepatitis B and hepatitis C to determine the effect of the policy change using segmented regression analyses at monthly time-points. Concurrently, we will undertake an integrated qualitative sub-study to understand the views of migrants and healthcare professionals to the new testing policy in primary care. Finally, we will evaluate the cost-effectiveness of combined infection testing for migrants in primary care.Ethics and dissemination The study has received HRA and NHS approvals for both the interrupted time-series analysis (16/SC/0127) and the qualitative sub-study (16/EM/0159). For the interrupted time-series analysis we will only use fully anonymised data. For the qualitative sub-study, we will gain written, informed, consent. Dissemination of the results will be through local

Journal article

Baggaley R, Owen B, Silhol R, Elmes J, Anton P, McGowan I, van der Straten A, Shacklett B, Dang Q, Swann EM, Bolton DL, Boily MCet al., 2018, Does per-act HIV-1 transmission risk through anal sex vary by gender? An updated systematic review and meta-analysis, American Journal of Reproductive Immunology, Vol: 80, ISSN: 1046-7408

Quantifying HIV‐1 transmission risk per‐act of anal intercourse (AI) is important for HIV‐1 prevention. We updated previous reviews by searching Medline and Embase to 02/2018. We derived pooled estimates of receptive AI (URAI) and insertive AI (UIAI) risk unprotected by condoms using random‐effects models. Subgroup analyses were conducted by gender, study design, and whether antiretroviral treatment (ART) had been introduced by the time of the study. Two new relevant studies were identified, one of which met inclusion criteria, adding three new cohorts and increasing number of individuals/partnerships included from 1869 to 14 277. Four studies, all from high‐income countries, were included. Pooled HIV‐1 risk was higher for URAI (1.25%, 95% CI 0.55%‐2.23%, N = 5, I2 = 87%) than UIAI (0.17%, 95 % CI 0.09%‐0.26%, N = 3, I2 = 0%). The sole heterosexual URAI estimate (3.38%, 95% CI 1.85%‐4.91%), from a study of 72 women published in a peer‐reviewed journal, was significantly higher than the men‐who‐have‐sex‐with‐men (MSM) pooled estimate (0.75%, 95% CI 0.56%‐0.98%, N = 4, P < 0.0001) and higher than the only other heterosexual estimate identified (0.4%, 95% CI 0.08%‐2.0%, based on 59 women, excluded for being a pre‐2013 abstract). Pooled per‐act URAI risk varied by study design (retrospective‐partner studies: 2.56%, 95% CI 1.20%‐4.42%, N = 2 (one MSM, one heterosexual); prospective studies: 0.71%, 95% CI 0.51%‐0.93%, N = 3 MSM, P < 0.0001). URAI risk was lower for studies conducted in the ART era (0.75%, 95% CI 0.52%‐1.03%) than pre‐ART (1.67%, 95% CI 0.44%‐3.67%) but not significantly so (P = 0.537). Prevention messages must emphasize that HIV‐1 infectiousness through AI remains high, even in the ART era. Further studies, particularly among heterosexual populations and in resource‐limited settings, are required to elucidate whether AI risk differs by gender, region and following population‐level ART scale‐up.

Journal article

Baggaley RF, Owen BN, Silhol R, Elmes J, Anton P, McGowan I, van der Straten A, Dang Q, Swann EM, Shacklett B, Boily M-Cet al., 2018, Per Act HIV Transmission Risk Through Anal Intercourse: An Updated Systematic Review and Meta-analysis, HIV Research for Prevention Meeting (HIVR4P) - AIDS Vaccine, Microbicide and ARV-Based Prevention Science, Publisher: MARY ANN LIEBERT, INC, Pages: 391-391, ISSN: 0889-2229

Conference paper

Owen BN, Maheu-Giroux M, Baral S, Baggaley RF, Boily M-Cet al., 2018, Prevalence and Determinants of Anal Intercourse Among Female Sex Workers in Swaziland, HIV Research for Prevention Meeting (HIVR4P) - AIDS Vaccine, Microbicide and ARV-Based Prevention Science, Publisher: MARY ANN LIEBERT, INC, Pages: 233-233, ISSN: 0889-2229

Conference paper

Baggaley RF, Irvine MA, Leber W, Cambiano V, Figueroa J, McMullen H, Anderson J, Santos AC, Terris-Prestholt F, Miners A, Hollingsworth TD, Griffiths CJet al., 2017, Cost-effectiveness of screening for HIV in primary care: a health economics modelling analysis, Lancet HIV, Vol: 4, Pages: E465-E474, ISSN: 2405-4704

BackgroundEarly HIV diagnosis reduces morbidity, mortality, the probability of onward transmission, and their associated costs, but might increase cost because of earlier initiation of antiretroviral treatment (ART). We investigated this trade-off by estimating the cost-effectiveness of HIV screening in primary care.MethodsWe modelled the effect of the four-times higher diagnosis rate observed in the intervention arm of the RHIVA2 randomised controlled trial done in Hackney, London (UK), a borough with high HIV prevalence (≥0·2% adult prevalence). We constructed a dynamic, compartmental model representing incidence of infection and the effect of screening for HIV in general practices in Hackney. We assessed cost-effectiveness of the RHIVA2 trial by fitting model diagnosis rates to the trial data, parameterising with epidemiological and behavioural data from the literature when required, using trial testing costs and projecting future costs of treatment.FindingsOver a 40 year time horizon, incremental cost-effectiveness ratios were £22 201 (95% credible interval 12 662–132 452) per quality-adjusted life-year (QALY) gained, £372 207 (268 162–1 903 385) per death averted, and £628 874 (434 902–4 740 724) per HIV transmission averted. Under this model scenario, with UK cost data, RHIVA2 would reach the upper National Institute for Health and Care Excellence cost-effectiveness threshold (about £30 000 per QALY gained) after 33 years. Scenarios using cost data from Canada (which indicate prolonged and even higher health-care costs for patients diagnosed late) suggest this threshold could be reached in as little as 13 years.InterpretationScreening for HIV in primary care has important public health benefits as well as clinical benefits. We predict it to be cost-effective in the UK in the medium term. However, this intervention might be cost-effective far sooner, and even cost-saving, in settings where long-term health-car

Journal article

Owen B, Elmes J, Silhol R, Dang Q, McGowan I, Shacklett B, Swann EM, van der Straten A, Baggaley RF, Boily MCet al., 2017, How common and frequent is heterosexual anal intercourse among South Africans? A systematic review and meta-analysis, Journal of International AIDS Society, Vol: 20, ISSN: 1758-2652

Background: HIV is transmitted more effectively during anal intercourse (AI) than vaginal intercourse (VI). However, patterns of heterosexual AI practice and its contribution to South Africa’s generalized epidemic remain unclear. We aimed to determine how common and frequent heterosexual AI is in South Africa.Methods: We searched for studies reporting the proportion practising heterosexual AI (prevalence) and/or the number of AI and unprotected AI (UAI) acts (frequency) in South Africa from 1990 to 2015. Stratified random-effects meta-analysis by subgroups was used to produce pooled estimates and assess the influence of participant and study characteristics on AI prevalence. We also estimated the fraction of all sex acts which were AI or UAI and compared condom use during VI and AI.Results: Of 41 included studies, 31 reported on AI prevalence and 14 on frequency, over various recall periods. AI prevalence was high across different recall periods for sexually active general-risk populations (e.g. lifetime = 18.4% [95%CI:9.4–27.5%], three-month = 20.3% [6.1–34.7%]), but tended to be even higher in higher-risk populations such as STI patients and female sex workers (e.g. lifetime = 23.2% [0.0–47.4%], recall period not stated = 40.1% [36.2–44.0%]). Prevalence was higher in studies using more confidential interview methods. Among general and higher-risk populations, 1.2–40.0% and 0.7–21.0% of all unprotected sex acts were UAI, respectively. AI acts were as likely to be condom protected as vaginal acts.Discussion: Reported heterosexual AI is common but variable among South Africans. Nationally and regionally representative sexual behaviour studies that use standardized recall periods and confidential interview methods, to aid comparison across studies and minimize reporting bias, are needed. Such data could be used to estimate the extent to which AI contributes to South Africa’s HIV epidemic.

Journal article

Ruzafa JC, Merinopoulou E, Baggaley RF, Leighton P, Werther W, Felici D, Cox Aet al., 2016, Patient population with multiple myeloma and transitions across different lines of therapy in the USA: an epidemiologic model, PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Vol: 25, Pages: 871-879, ISSN: 1053-8569

Journal article

Cavallaro FL, Duclos D, Baggaley RF, Penn-Kekana L, Goodman C, Vahanian A, Santos AC, Bradley J, Paintain L, Gallien J, Gasparrini A, Hasselback L, Lynch CAet al., 2016, Taking stock: protocol for evaluating a family planning supply chain intervention in Senegal, REPRODUCTIVE HEALTH, Vol: 13, ISSN: 1742-4755

Journal article

Campbell OMR, Benova L, MacLeod D, Baggaley RF, Rodrigues LC, Hanson K, Powell-Jackson T, Penn-Kekana L, Polonsky R, Footman K, Vahanian A, Pereira SK, Santos AC, Filippi VGA, Lynch CA, Goodman Cet al., 2016, Family planning, antenatal and delivery care: cross-sectional survey evidence on levels of coverage and inequalities by public and private sector in 57 low- and middle-income countries, TROPICAL MEDICINE & INTERNATIONAL HEALTH, Vol: 21, Pages: 486-503, ISSN: 1360-2276

Journal article

Medley GF, Turner HC, Baggaley RF, Holland C, Hollingsworth TDet al., 2016, The Role of More Sensitive Helminth Diagnostics in Mass Drug Administration Campaigns: Elimination and Health Impacts, ADVANCES IN PARASITOLOGY, VOL 94: MATHEMATICAL MODELS FOR NEGLECTED TROPICAL DISEASES: ESSENTIAL TOOLS FOR CONTROL AND ELIMINATION, PT B, Editors: Basanez, Anderson, Publisher: ELSEVIER ACADEMIC PRESS INC, Pages: 343-392

Book chapter

Moraga P, Cano J, Baggaley RF, Gyapong JO, Njenga SM, Nikolay B, Davies E, Rebollo MP, Pullan RL, Bockarie MJ, Hollingsworth TD, Gambhir M, Brooker SJet al., 2015, Modelling the distribution and transmission intensity of lymphatic filariasis in sub-Saharan Africa prior to scaling up interventions: Integrated use of geostatistical and mathematical modelling, Parasites & Vectors, Vol: 8, ISSN: 1756-3305

Background: Lymphatic filariasis (LF) is one of the neglected tropical diseases targeted for global elimination. The ability to interrupt transmission is, partly, influenced by the underlying intensity of transmission and its geographical variation. This information can also help guide the design of targeted surveillance activities. The present study uses a combination of geostatistical and mathematical modelling to predict the prevalence and transmission intensity of LF prior to the implementation of large-scale control in sub-Saharan Africa. Methods: A systematic search of the literature was undertaken to identify surveys on the prevalence of Wuchereria bancrofti microfilaraemia (mf), based on blood smears, and on the prevalence of antigenaemia, based on the use of an immuno-chromatographic card test (ICT). Using a suite of environmental and demographic data, spatiotemporal multivariate models were fitted separately for mf prevalence and ICT-based prevalence within a Bayesian framework and used to make predictions for non-sampled areas. Maps of the dominant vector species of LF were also developed. The maps of predicted prevalence and vector distribution were linked to mathematical models of the transmission dynamics of LF to infer the intensity of transmission, quantified by the basic reproductive number (R0). Results: The literature search identified 1267 surveys that provide suitable data on the prevalence of mf and 2817 surveys that report the prevalence of antigenaemia. Distinct spatial predictions arose from the models for mf prevalence and ICT-based prevalence, with a wider geographical distribution when using ICT-based data. The vector distribution maps demonstrated the spatial variation of LF vector species. Mathematical modelling showed that the reproduction number (R0) estimates vary from 2.7 to 30, with large variations between and within regions. Conclusions: LF transmission is highly heterogeneous, and the developed maps can help guide intervention

Journal article

Ruzafa JC, Merinopoulou E, Baggaley RF, Leighton P, Werther W, Felici D, Cox Aet al., 2015, Patient Population with Multiple Myeloma and Transitions Across Different Lines of Therapy in the US: An Epidemiologic Model, Publisher: WILEY-BLACKWELL, Pages: 29-30, ISSN: 1053-8569

Conference paper

Baggaley RF, Hollingsworth TD, 2015, HIV-1 transmissions during asymptomatic infection: exploring the impact of changes in HIV-1 viral load due to coinfections, Jaids-Journal of Acquired Immune Deficiency Syndromes, Vol: 68, Pages: 594-598, ISSN: 1944-7884

Abstract: High HIV-1 plasma viral loads (PVLs) in sub-Saharan Africa, partly because of high rates of coinfection, may have been one of the drivers of the “explosive” epidemics seen in that region. Using a previously published framework of infectiousness and survival, we estimate the excess onward HIV-1 transmission events (secondary infections) resulting from coinfection-induced changes in PVL during asymptomatic HIV-1 infection. For every 100 HIV-infected people, each suffering 1 episode of tuberculosis infection, there are 4.9 (2.7th–97.5th percentile: 0.2–21.5) excess onward HIV-1 transmission events attributable to this coinfection. Other estimates are malaria 0.4 (0.0–2.0), soil-transmitted helminths 3.1 (0.1–14.9), schistosomiasis 8.5 (0.2–38.6), filariasis 13.3 (0.3–89.2), syphilis 0.1 (0.0–1.6), herpes simplex virus 4.0 (0.0–24.2), and gonorrhea 2.1 (0.1–8.0) transmissions. If these higher PVLs confer a shorter life expectancy and higher infectiousness, then their impact on transmission is, in general, reduced. For most HIV-1 coinfections, the duration of a single infection is too short and/or the associated PVL elevation is too modest to contribute substantially to onward HIV-1 transmission.

Journal article

Lopez EL, Marta Contrini M, Mistchenko A, Kieffer A, Baggaley RF, Luca Di Tanna G, Desai K, Rasuli A, Armoni Jet al., 2015, Modeling the Long-term Persistence of Hepatitis A Antibody After a Two-Dose Vaccination Schedule in Argentinean Children, PEDIATRIC INFECTIOUS DISEASE JOURNAL, Vol: 34, Pages: 417-425, ISSN: 0891-3668

Journal article

Marsh K, Chapman R, Baggaley RF, Largeron N, Bresse Xet al., 2014, Mind the gaps: What's missing from current economic evaluations of universal HPV vaccination?, VACCINE, Vol: 32, Pages: 3732-3739, ISSN: 0264-410X

Journal article

Owen BN, Brock PM, Shubber Z, Baggaley RF, Butler AR, Pickles M, Brisson M, Drolet M, Boily MCet al., 2013, 31. Lifetime prevalence of anal intercourse among sexually active female youth and young female sex workers: a comparative systematic review and meta-analysis., ISSN: 1448-5028

Background Anal cancer incidence has increased over the past twenty years. Heterosexual anal intercourse (AI) is a risk factor for HPV and HIV infection but is under-researched and ill-understood. We compare AI practices among young, sexually active general population females and female sex workers (FSW). Methods: We searched PubMed for heterosexual AI studies among young females, including FSWs (mean age <25 years), to December 2012. Study estimates were pooled using a random-effects model. Results: Fifty-four studies (42 average-risk, 6 higher-risk, 6 FSWs) were included. Most studies among general population youth were conducted in North America using self-administered questionnaires. All FSW studies were conducted in Africa and Asia using face-to-face interviews (FTFI). Pooled estimates of lifetime AI prevalence were larger among average-risk (23.6%, 95% CI 20.4-26.7) and higher-risk youth (25.5%, 95% CI 11.7-39.2) than FSWs (12.8%, 95% CI 8.4-17.3), but highly heterogeneous (I2 >90%). However, pooled AI estimates by continent of average-risk youth (Asia=13.9%, 95% CI=1.7-29.5; Africa=18.4%, 95% CI 0.9-35.8) were more similar to those of FSWs (Asia=16.0%, 95% CI 10.3-21.6; Africa=9.7%, 95% CI 3.8-15.7). Estimates of average-risk youth reporting via FTFI (12.1%, 95% CI 0.7-23.5) were likewise similar to those among FSWs (12.8%, 95% CI 8.4-17.3). Pooled AI prevalence estimates among FSWs were higher in studies conducted after 2001 than in earlier studies. Conclusions: AI is common among sexually active females and may be increasing; it could therefore be an important determinant of HPV transmission and anal cancers. AI is as or more common among the general population youth than young FSWs but this may be confounded by continent, interview method and other unmeasured variables.

Conference paper

Owen BN, Brock PM, Baggaley RF, Butler AR, Pickles M, Brisson M, Drolet M, Boily Met al., 2013, HETEROSEXUAL ANAL INTERCOURSE AMONG YOUTH: A SYSTEMATIC REVIEW AND METAANALYSIS, SEXUALLY TRANSMITTED INFECTIONS, Vol: 89, Pages: A148-A148, ISSN: 1368-4973

Journal article

Baggaley RF, Dimitrov D, Owen BN, Pickles M, Butler AR, Masse B, Boily M-Cet al., 2013, Heterosexual Anal Intercourse: A Neglected Risk Factor for HIV?, AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Vol: 69, Pages: 95-105, ISSN: 1046-7408

Journal article

Owen BN, Brock PM, Shubber Z, Baggaley RF, Butler AR, Pickles M, Brisson M, Drolet M, Boily M-Cet al., 2013, Lifetime prevalence of anal intercourse among sexually active female youth and young female sex workers: a comparative systematic review and meta-analysis, Publisher: CSIRO PUBLISHING, Pages: 585-585, ISSN: 1448-5028

Conference paper

Baggaley RF, White RG, Hollingsworth TD, Boily MCet al., 2013, Heterosexual HIV-1 Infectiousness and Antiretroviral Use: Systematic Review of Prospective Studies of Discordant Couples., Epidemiology, Vol: 1, Pages: 110-121

BACKGROUND: : Recent studies have estimated the reduction in HIV-1 infectiousness with antiretroviral therapy (ART), but high-quality studies such as randomized controlled trials, accompanied by rigorous adherence counseling, are likely to overestimate the effectiveness of treatment-as-prevention in real-life settings.METHODS: : We attempted to summarize the effect of ART on HIV transmission by undertaking a systematic review and meta-analysis of HIV-1 infectiousness per heterosexual partnership (incidence rate and cumulative incidence over study follow-up) estimated from prospective studies of discordant couples. We used random-effects Poisson regression models to obtain summary estimates. When possible, the analyses were further stratified by direction of transmission (man-to-woman or woman-to-man) and economic setting (high- or low-income countries). Potential causes of heterogeneity of estimates were explored through subgroup analyses.RESULTS: : Fifty publications were included. Nine allowed comparison between ART and non-ART users within studies (ART-stratified studies), in which summary incidence rates were 3.6/100 person-years (95% confidence interval = 2.0-6.5) and 0.2/100 person-years (0.07-0.7) for non-ART- and ART-using couples, respectively (P < 0.001), constituting a 91% (79-96%) reduction in per-partner HIV-1 incidence rate with ART use. The 41 studies that did not stratify by ART use provided estimates with high levels of heterogeneity (I statistic) and few reported levels of ART use, making interpretation difficult. Nevertheless, estimates tended to be lower with ART use. Infectiousness tended to be higher for low-income than high-income settings, but there was no clear pattern by direction of transmission (man-to-woman and woman-to-man).CONCLUSIONS: : ART substantially reduces HIV-1 infectiousness within discordant couples, based on observational studies, and could play a major part in HIV-1 prevention efforts. However, the non-zero risk from par

Journal article

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