Near Real-Time Monitoring of HIV-1 Transmission Hotspots in Cyprus from Phylogenetics: The Cyprus HIV-1 Transmission Cohort Study (CHICS)

In Cyprus, the number of newly infected individuals has nearly tripled since the early 2000s, reaching to 85 new cases in 2018. Advanced phylogenetic-based analyses of HIV-1 genomic sequences from HIV-1 sequence databases provide detailed knowledge of HIV-1 transmission dynamics in human populations which is important in identifying populations at risk and better design intervention strategies.

The Cyprus HIV Transmission Cohort Study (CHICS) is a densely-sampled, prospective, cross-sectional HIV-1 transmission database of newly-diagnosed patients in Cyprus that enables detailed phylogenetic clustering molecular studies in order to reveal HIV-1 transmission dynamics in Cyprus in near real-time. HIV-1 Transmission clusters are identified based on low nucleotide genetic distance and high branch support.

Monthly reports on the growth and characteristics of HIV-1 transmission clusters (hotspots) are generated by our laboratory and distributed to public health officers and also posted here. The results of this study have a direct impact on the clinical care of HIV-1-infected patients in Cyprus and further advance the implementation of HIV-1 treatment-as-prevention strategies and other intervention strategies to interrupt the spread of HIV-1 transmission in Cyprus. The study was approved by and is in accordance with the guidelines and regulations of the Cyprus National Bioethics Committee and the Office of the Commissioner for Personal Data Protection in Cyprus, and in accordance with the written consent of all participating study subjects. Study subjects are presented by a unique laboratory number to protect anonymity.

*APRIL REPORT*: There is a recently active and fast expanding subtype A1 HIV-1 transmission hotspot (indicated by the arrow on the phylogenetic tree) of young Cypriot men who have sex with men (referred to as MSM) who reported to be infected in Cyprus.