Joseph Larmarange

Adoption of HIV preexposure prophylaxis (PrEP) among female sex workers (FSWs) in Côte d'Ivoire: complex trajectories and early adopters

Joseph LARMARANGE — 2025-07-15T15:10:30Z

Adoption of HIV preexposure prophylaxis (PrEP) among female sex workers (FSWs) in Côte d'Ivoire: complex trajectories and early adopters

Joseph Larmarange , Mélanie Plazy , Marcellin Nouaman , Evelyne Kissi , Rose-Marcelle Dedocoton , Patrick Coffie , Serge Eholié , Valentine Becquet

IAS 2025, the 13th IAS Conference on HIV Science, International AIDS Society, Jul 2025, Kigali, Rwanda

Communication dans un congrès

hal-05163730

Authors

Joseph Larmarange, Mélanie Plazy, Marcellin Nouaman, Evelyne Kissi, Rose-Marcelle Dedocoton, Patrick Coffie, Serge Eholié, Valentine Becquet

Abstract

BACKGROUND: The ANRS 12381 PRINCESSE project (11/2019-06/2023) enrolled 489 FSWs and implemented community-based sexual and reproductive health care, including PrEP, delivered through mobile clinics at prostitution sites in the San Pedro region. This presentation aims to describe PrEP trajectories and the factors associated with its use, focusing on “early adopters”.

METHODS: This analysis included 400 FSWs eligible for PrEP (HIV-negative, HBsAg-negative) enrolled up to December 2022 (>6 months of follow-up). Clinical records were analyzed to describe PrEP cascade, follow-up, and PrEP trajectories. A multivariable logistic regression identified factors associated with PrEP early adopters.

RESULTS: Although 98% of eligible FSWs were interested in PrEP, only 62% initiated PrEP, and 39% renewed it at least once.
Follow-up was very short (<6 months) for 48%, short (6-12 months) for 15%, seasonal (>12 months with a gap of 6 months between two visits) for 31%, and regular (>12 months with no gap) for 6%.
PrEP initiation was high among FSWs with regular (96%), seasonal (83%), or short (80%) follow-up, vs. 39% for those with very short follow-up. Among those who initiated, only 88% (regular), 70% (seasonal), 74% (short), and 35% (very short) renewed PrEP.
Among 148 FSWs with regular/seasonal follow-up, four PrEP trajectories were identified (cf. figure showing individual trajectories): 15% “never initiated” PrEP, 39% “initiated and were later not interested anymore”, 18% “re-initiated after non-interest”, and 28% “initiated and never expressed non-interest”, the last two groups being considered as “early adopters”. Factors associated with early PrEP adoption included the usual price of intercourse with clients <1500 FCFA (aOR=2.4 [1.2-4.8]) and working in brothels (aOR=3.2 [1.6-6.6]).


Figure presenting individual PrEP trajectories of FSWs enrolled in the PRINCESSE project

CONCLUSIONS: In PRINCESSE, loss-to-follow-up and seasonality of risks limited PrEP adoption. FSWs who were more precarious and less mobile became early adopters of this new prevention tool and could serve as potential ambassadors for promoting its uptake.

Décrire les épidémies, Comprendre les populations : une démographie du VIH en Afrique subsaharienne

Joseph LARMARANGE — 2022-10-14T06:38:12Z

Habilitation à Diriger des Recherches soutenue le 12 octobre 2012 par Joseph Larmarange à l'Université Paris Cité.
Décrire les épidémies, Comprendre les populations : une démographie du VIH en Afrique subsaharienne
Joseph Larmarange Démographie. Université Paris Cité, 2022 HDR tel-03814024

- Publications / Afrique subsaharienne, ATLAS, CAP-CoV-Soignants-BF, DOD-CI (ANRS 12287 / 12323), ELIHoS (ANRS 12139), PrEP CI (ANRS 12361), Prévalences du VIH (ANRS 12114), prevR, PRINCESSE, TasP (ANRS 12249), Afrique du Sud, Burkina Faso, Côte d'Ivoire, Mali, Sénégal, Accès aux soins, Analyse de séquences, Approches biographiques, Approches communautaires, Autotests VIH, Cartographie, Cascade des soins, Comparaison de cohortes, Comportements sexuels, Démographie, Dépistage, EDS (Enquêtes Démographiques et de Santé), Enquêtes par téléphone, Enseignement académique, Lien vers les soins, Épidémiologie, Essais cliniques, Estimateurs à noyau (kernel density estimation), Femmes enceintes, Financement des programmes, Hépatites virales, Homo / Bisexualités, Identités sexuelles, Incidence du VIH, Interpolation spatiale, IST (Infections Sexuellement Transmissibles), Itinéraires thérapeutiques, Masculinités, Ménages, Mesure d'impact, Mesure des indicateurs, Méthodologie, Migrations, Observatoire de population, Partenaires sexuel(le)s, PrEP, Prévalence du VIH, Prévention, Prise en charge, Recherche interventionnelle, Recherche participative/communautaire, Recrutement « boules de neige », Représentations / Perceptions, Représentativité et Biais, Santé publique, Santé sexuelle, Structure des populations, Structures de santé, Surveillance sentinelle, Téléphones mobiles, Temporalités, Traitement antirétroviral (ARV), Travail du sexe, Treatment as Prevention (TasP), Universal Test & Treat (UTT), Usageres de drogue, VIH / SIDA

Un même objet biographique sous l'angle de plusieurs approches méthodologiques

Joseph LARMARANGE — 2018-10-19T14:03:53Z

Communication orale présentée le 18 octobre 2018 à Paris dans le cadre du colloque Parcours de vie et santé : apports des méthodes biographiques en santé publique.
L'ensemble des analyses et le code correspondant est disponible sur http://larmarange.github.io/analyse-R/trajectoires-de-soins.html Référence
Larmarange Joseph (2018) « Un même objet biographique sous l'angle de plusieurs approches méthodologiques » (communication orale), présenté à Parcours de vie et santé : apports des (…)

- Communications / Méthodologie, Mesure des indicateurs, Accès aux soins, Représentativité et Biais, Régression logistique, Démographie, Programmation / Code, Analyse de séquences, Classification hiérarchique, Cascade des soins, Approches biographiques

From home-based HIV testing to viral suppression: HIV care trajectories in the context of Universal Test-and-Treat in rural South Africa

Joseph LARMARANGE — 2018-06-06T14:55:16Z

Oral communication presented May 31 2018 at Life History Research Society Conference in Paris.

Authors

Delphine Perriat, Mamadou Hassimiou Diallo, François Dabis, Deenan Pillay, Joanna Orne-Gliemann, Joseph Larmarange for the ANRS 12249 TasP Study Group

Abstract

Background: In order for people living with HIV to achieve an undetectable viral load, and thus live longer and healthier, they need access to a continuum of services. There are numerous reports of “leaks” at all steps of the HIV care cascade. We described the timing and sequencing of individual HIV care statuses from care referral to viral suppression, by identifying groups of individuals with similar trajectories and factors associated.

Sample: We used prospective individual-level longitudinal data from the ANRS 12249 TasP cluster-randomized trial, which investigated the impact of universal antiretroviral treatment (ART) on HIV incidence in rural South Africa (2012-2016). We included trial participants >16 years, identified HIV+, not in care at referral and followed-up for ≥18 months.

Method: The care status of all study participants was classified for each calendar day as: not in care, in care but not on ART, on ART but not virally suppressed, virally suppressed. We used state sequence data analysis to identify homogeneous care trajectories groups. A multinomial logistic regression was used to identify the profile of each group in terms of individual and cluster characteristics.

Results: 1,816 participants were included. Median age was 34 years [IQR 27-45], 74% were female. We identified four care trajectories groups: (i) participants who mostly did not enter care (55%), (ii) participants with inconstant care, visiting a clinic occasionally but leaving care thereafter (median time to exit care: 10 m. [5.2-13]) (12%), (iii) participants who took extensive time at each step of the care continuum (median time between referral and ART: 8.0 m. [6.4-9.7]) (12%) and (iv) participants who rapidly progressed towards continuous care (median time between referral and ART: 1.2 m. [0.6-2.7]) (21%). Participants younger than 50 years, newly diagnosed at referral, living further than a kilometre from a trial clinic, and living in a cluster were immediate ART was not offered, were more likely to present with incomplete, inconstant and slow care trajectories.

Conclusions: A longitudinal and person-specific approach to the study of HIV care patterns contributed to highlight the heterogeneity in care trajectories, in terms of speed and care utilization behaviours. Differentiated and personalised care and support should be scaled-up, especially between diagnosis and ART initiation, which constitutes the main bottleneck of HIV programs in this South African rural study area.

Keywords: State sequence data analysis, HIV care, South Africa

Reference

Perriat Delphine, Diallo Mamadou Hassimiou, Dabis François, Pillay Deenan, Orne-Gliemann Joanna, Larmarange Joseph et ANRS 12249 TasP Study Group (2018) « From home-based HIV testing to viral suppression : HIV care trajectories in the context of Universal Test-and-Treat in rural South Africa » (communication orale), présenté à Life History Research Society Conference, Paris.

Participation Dynamics in Population-Based Longitudinal HIV Surveillance in Rural South Africa

Joseph LARMARANGE — 2015-04-21T07:03:13Z

Authors

Joseph Larmarange
Joël Mossong
Till Bärnighausen
Marie Louise Newell

Abstract

Population-based HIV surveillance is crucial to inform understanding of the HIV pandemic and evaluate HIV interventions, but little is known about longitudinal participation patterns in such settings. We investigated the dynamics of longitudinal participation patterns in a high HIV prevalence surveillance setting in rural South Africa between 2003 and 2012, taking into account demographic dynamics. At any given survey round, 22,708 to 30,495 persons were eligible. Although the yearly participation rates were relatively modest (26% to 46%), cumulative rates increased substantially with multiple recruitment opportunities: 68% of eligible persons participated at least once, 48% at least twice and 31% at least three times after five survey rounds. We identified two types of study fatigue: at the individual level, contact and consent rates decreased with multiple recruitment opportunities and, at the population level, these rates also decreased over calendar time, independently of multiple recruitment opportunities. Using sequence analysis and hierarchical clustering, we identified three broad individual participation profiles: consenters (20%), switchers (43%) and refusers (37%). Men were over represented among refusers, women among consenters, and temporary non-residents among switchers. The specific subgroup of persons who were systemically not contacted or refusers constitutes a challenge for population-based surveillance and interventions.

Citation

Larmarange Joseph, Mossong Joël, Bärnighausen Till et Newell Marie Louise (2015) « Participation Dynamics in Population-Based Longitudinal HIV Surveillance in Rural South Africa », PLoS ONE, 10 (4), p. e0123345. DOI : 10.1371/journal.pone.0123345. http://dx.doi.org/10.1371/journal.pone.0123345.

Représenter un tapis de séquences ordonnées selon un dendrogramme

Joseph LARMARANGE — 2013-03-11T12:22:30Z

La fonction seq_heatmap est maintenant disponible dans le package JLutils.

Nicolas Robette a écrit un excellent article d'introduction à l'analyse de séquences sur le blog Quanti.hypotheses.org (voir L'analyse de séquences : une introduction avec le logiciel R et le package TraMineR).

Il y montre notamment comment calculer une distance entre séquences, ce qui permet ensuite d'effectuer une classification hiérarchique pour regrouper les différentes séquences en un nombre limité de classes en fonction de leur proximité.

Un des modes de représentation proposé par le package TraMineR est appelé “tapis”. Les tapis permettent de mieux visualiser la dimension individuelle des séquences. Chaque segment horizontal représente une séquence, découpée en sous-segments correspondant aux aux différents états successifs qui composent la séquence.

Nous proposons ici une petite astuce permettant de représenter sur un même graphique le tapis des séquences et le dendrogramme de la classification hiérarchique, les séquences étant alors triées selon les regroupements du dendrogramme, permettant de mieux comprendre comment se constituent les différentes classes.

Ce type de représentation s'inspire des heat map et utilise d'ailleurs la fonction native heatmap() fournie par R.

Voici en premier lieu le code à copier/coller dans R pour définir la fonction seq_heatmap :

seq_heatmap <- function (seq, tree, with.missing=FALSE, ...) { if (class(tree)!="dendrogram") tree <- as.dendrogram(tree) mat <- seq for (i in 1:length(seq)){ mat[mat[,i]=="%",i] <- NA mat[,i] <- as.numeric(mat[,i]) } mat <- as.matrix(mat) col <- attr(seq,"cpal") if (with.missing) col <- c(col,attr(seq,"missing.color")) heatmap(mat, tree, NA, na.rm=FALSE, col=col, scale="none", labRow=NA, ...) }

Il suffit ensuite d'appeler cette fonction en lui passant en premier lieu le tableau des séquences défini à l'aide de la fonction seqdef() et en second le dendrogramme obtenu avec hclust() ou agnes() [1].

Pour reprendre les données fournies en exemple par Nicolas Robette, on saisira
seq_heatmap(seq,seq.agnes,labCol=14:50) pour obtenir le résultat ci-dessous :

[1] Au passage j'en profite pour citer l'excellent package flashClust. Le calcul d'un dendrogramme peut être particulièrement long si le fichier de données est important. Ce package permet de réduire très significativement le temps de calcul.

Joseph Larmarange

Adoption of HIV preexposure prophylaxis (PrEP) among female sex workers (FSWs) in Côte d'Ivoire: complex trajectories and early adopters

Adoption of HIV preexposure prophylaxis (PrEP) among female sex workers (FSWs) in Côte d'Ivoire: complex trajectories and early adopters

Authors

Abstract

See also

Perceptions regarding long-acting pre-exposure prevention (PrEP) among female sex workers and men having sex with men in San Pedro and Abidjan, Côte d'Ivoire

Décrire les épidémies, Comprendre les populations : une démographie du VIH en Afrique subsaharienne

Un même objet biographique sous l'angle de plusieurs approches méthodologiques

From home-based HIV testing to viral suppression: HIV care trajectories in the context of Universal Test-and-Treat in rural South Africa

Authors

Abstract

Reference

Participation Dynamics in Population-Based Longitudinal HIV Surveillance in Rural South Africa

Authors

Abstract

Citation

Représenter un tapis de séquences ordonnées selon un dendrogramme