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The University of Southampton
CORMSIS Centre for Operational Research, Management Sciences and Information Systems

The network topography connecting people who inject drugs has important implications for treatment as prevention of Hepatitis C -- talk by Dr Ryan Buchanan (Southampton) Event

14:00 - 16:00
4 April 2019
Building 02, Room 3041, Business School, University of Southampton, Highfield Campus, SO17 1BJ

For more information regarding this event, please email Dr Sally Brailsford at .

Event details


People who inject drugs (PWID) are connected via injecting partnerships that facilitate the transmission of Hepatits C (HCV). The treatment of HCV in PWID could prevent further disease transmission. However, the real-world effect of this is unknown and it is likely to depend on the topology of the injecting partnership network.

In this study we describe an injecting network of PWID living in an isolated community on the Isle of Wight (UK) and the results of a simulation testing the effect of treatment as prevention (TasP).



PWID were identified via respondent driven sampling and recruited to a network and bio-behavioural survey. The injecting network they described formed the baseline population and potential transmission pathways in an agent based simulation of HCV transmission and the effects of treatment over 12 months.



On average each PWID had 2.6 injecting partners (range 0-14) and 137 were connected into a single component. HCV in the network was associated with a higher proportion of positive injecting partners (p=0.003) and increasing age (p=0.011).

The treatment of well-connected PWID led to significantly fewer new infections of HCV than treating at random (10 vs. 6, P<0.0001).  In all scenarios less than one individual was re-infected.



The study indicates that PWID are linked via injecting partnerships into a ‘scale-free’ network.  The preferential treatment of well-connected PWID could maximise TasP and contribute to a future effective HCV elimination strategy.




Speaker information

Dr Ryan Buchanan, University of Southampton, is an Academic Clinical Lecturer in Gastroenterology and Hepatology at the University of Southampton. His PhD mapped a network of people who inject drugs on the Isle of Wight and tested the effect of treatment on the transmission of Hepatitis C. Whilst undertaking his research he set up an outreach Hepatitis C testing and treatment service on the Isle of Wight and now leads of team aiming to eliminate the virus from the Southampton City area. Ryan balances his research with clinical training in Hepatology. In the medium term he hopes to continue his research interests and balance these with his clinical commitments as a Hepatology consultant.

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