Combining the Estimated Date of HIV Infection with a Phylogenetic Cluster Study to Better Understand HIV Spread: Application in a Paris Neighbourhood.
OBJECTIVE
To relate socio-demographic and virological information to phylogenetic clustering in HIV infected patients in a limited geographical area and to evaluate the role of recently infected individuals in the spread of HIV.


METHODS
HIV-1 pol sequences from newly diagnosed and treatment-naive patients receiving follow-up between 2008 and 2011 by physicians belonging to a health network in Paris were used to build a phylogenetic tree using neighbour-joining analysis. Time since infection was estimated by immunoassay to define recently infected patients (very early infected presenters, VEP). Data on socio-demographic, clinical and biological features in clustered and non-clustered patients were compared. Chains of infection structure was also analysed.


RESULTS
547 patients were included, 49 chains of infection containing 108 (20%) patients were identified by phylogenetic analysis. analysis. Eighty individuals formed pairs and 28 individuals were belonging to larger clusters. The median time between two successive HIV diagnoses in the same chain of infection was 248 days [CI = 176-320]. 34.7% of individuals were considered as VEP, and 27% of them were included in chains of infection. Multivariable analysis showed that belonging to a cluster was more frequent in VEP and those under 30 years old (OR: 3.65, 95 CI 1.49-8.95, p = 0.005 and OR: 2.42, 95% CI 1.05-5.85, p = 0.04 respectively). The prevalence of drug resistance was not associated with belonging to a pair or a cluster. Within chains, VEP were not grouped together more than chance predicted (p = 0.97).


CONCLUSIONS
Most newly diagnosed patients did not belong to a chain of infection, confirming the importance of undiagnosed or untreated HIV infected individuals in transmission. Furthermore, clusters involving both recently infected individuals and longstanding infected individuals support a substantial role in transmission of the latter before diagnosis.
Service Universitaire Régional de Maladies Infectieuses et Tropicales, Centre Hospitalier de Tourcoing, Tourcoing, France; INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France.
Olivier
O
Robineau
EA 3620, Université Paris Descartes, Sorbonne Paris-Cité, Paris, France; Laboratoire de Microbiologie & Unité d'Immunologie, Hématologie et Rhumatologie Pédiatriques, AP-HP, Hôpital Necker, Enfants Malades, Paris, France.
Pierre
P
Frange
Centre National de Référence du VIH & INSERM U966, CHU Bretonneau & Université Francois Rabelais, Tours, France.
Francis
F
Barin
Institut de Veille Sanitaire, Saint-Maurice, France.
Françoise
F
Cazein
INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France; Service des Maladies Infectieuses et Tropicales, Hôpital Saint Antoine, APHP, Paris, France.
Pierre-Marie
PM
Girard
EA 3620, Université Paris Descartes, Sorbonne Paris-Cité, Paris, France; Laboratoire de Virologie, AP-HP, Hôpital Saint-Louis, Paris, France.
Marie-Laure
ML
Chaix
Laboratoire du Chemin Vert, Paris, France.
Georges
G
Kreplak
INSERM, UMR_S 1136, Institut Pierre Louis d'Epidémiologie et de Santé Publique, Paris, France; Sorbonne Universités, UPMC Univ Paris 06, UMR_S 943, Paris, France; Service de Santé Publique, AP-HP, Hôpital Saint-Antoine, Paris, France.
Pierre-Yves
PY
Boelle
INSERM, UMR_S 943, Paris, France; Laboratoire de Virologie, Hôpital Saint-Antoine, AP-HP, Paris, France.
Laurence
L
Morand-Joubert
D015492:AIDS Serodiagnosis; D000328:Adult; D005260:Female; D005838:Genotype; D015658:HIV Infections / Q000175:diagnosis / Q000453:epidemiology* / Q000821:virology; D015497:HIV-1 / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D010297:Paris; D010802:Phylogeny