11 July 2019

new study modelling the impact of increased treatment of hepatitis C virus (HCV) infection among people who inject drugs in the US has found that an increase of clean injecting equipment provided through syringe service programmes, provision of medication assisted treatment (MAT), and antiviral treatment for hepatitis C (HCV) among people who inject drugs could reduce the incidence of HCV in the United States by 90% by 2030.

The research, conducted at Bristol Medical School, University of Bristol and RTI International, a non-profit research institute, and funded by the US Centers for Disease Control and Prevention, lines up with a target for HCV elimination set by the US National Academies of Sciences, Engineering and Medicine (NASEM). The study used mathematical models to estimate the impact of scaling up harm reduction services and HCV treatment in San Francisco, California, and Perry County, Kentucky. The results were published in the American Journal of Epidemiology [10 July 2019].

“Our modelling shows that modest scale-up of HCV treatment, combined with syringe service program and medication assisted treatment, can reverse the HCV burden in the United States and potentially achieve elimination goals in the next 10 to 15 years,” said Dr Hannah Fraser, Senior Research Associate in Infectious Disease Mathematical Modelling at the NIHR Health Protection Research Unit in Evaluation of Interventions at the University of Bristol, and lead author of the study.

“We are facing an expanding epidemic of HCV among people who inject drugs due to the ongoing opioid epidemic. Our research suggests that elimination goals can be achieved in both large cities and rural areas in the United States,” said Dr Thomas Hoerger, Senior Fellow at RTI International, and one of the study authors.

San Francisco has an established community of people who inject drugs and a fairly constant HCV prevalence. In contrast, rural Perry County has an increasing HCV epidemic alongside a young and expanding population of people who inject drugs. Using data from San Francisco and Perry County, the researchers developed mathematical models to estimate the number of people who inject drugs who would need to be treated to reduce HCV incidence by 90% by 2030, both in combination and without increasing harm reduction services. In San Francisco, there is currently high coverage of syringe service programs with moderate medication assisted treatment, while at the time of modelling, no syringe service programs existed in Perry County, with minimal medication assisted treatment.

Assuming increases in syringe service programs (in Perry County) and increases in medication assisted treatment (both places), to achieve the elimination target in San Francisco 1,418 people who inject drugs initially need to be treated each year with a total of 19,019 needing treatment between 2017-2030. Due to the smaller population size in Perry County, only 22 people who inject drugs initially need treatment each year to achieve the target – totalling 288 treatments between 2017-2030.

The researchers found that not increasing the provision of harm reduction services more than doubled the number of treatments needed for elimination in Perry County, whereas it had little effect in San Francisco because existing provision of harm reduction services is much higher.

“Field studies are now needed to demonstrate the feasibility and impact of such strategies. This will help to inform harm reduction policy, and therefore, potentially enable the United States to reduce HCV as a public health threat,” said Peter Vickerman, Professor of Infectious Disease Modelling at the University of Bristol, who supervised the study.

Hepatitis C is a blood-borne infection that can seriously damage the liver and cause death if left untreated. Around 3.5 million people are infected with HCV in the US and the majority of new infections are acquired through injecting drugs, according to the U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Reported cases of acute HCV infections have tripled since 2010, coinciding with increases in injection of opiates and other drugs. 

Harm reduction services include syringe service programmes which provide sterile injecting equipment, and medication assisted treatment, usually with methadone, which aims to reduce the use and injection of illicit drugs. However, the availability of these services varies widely across the US. Recent advances in HCV treatment with direct-acting antiviral medications can reduce HCV to undetectable levels in most patients.

Paper: Scaling up hepatitis C prevention and treatment interventions for achieving elimination in the United States: A rural and urban comparison by Hannah Fraser et al. Published in American Journal of Epidemiology. July 2019.

Further information

About the NIHR HPRU in Evaluation of Interventions at the University of Bristol

The Health Protection Research Unit (HPRU) in Evaluation of Interventions, based in Population Health Sciences at the University of Bristol, is part of the National Institute for Health Research (NIHR) and a partnership between University of Bristol and Public Health England (PHE), in collaboration with University College London, Cambridge Medical Research Council (MRC) Biostatistics Unit and University of the West of England. We are a multidisciplinary team undertaking applied research on the development and evaluation of interventions to protect the public’s health. Our aim is to support PHE in delivering its objectives and functions. Our focus is on the PHE priority area of infection. Follow us on Twitter: @HPRU_EI 

About the University of Bristol

The University of Bristol is ranked within the top 10 universities in the UK and top 50 in the world (QS World University Rankings 2020); it is also ranked among the top five institutions in the UK for its research, according to new analysis of the Research Excellence Framework (REF) 2014; and is the 2nd most targeted university by top UK employers.

The University was founded in 1876 and was granted its Royal Charter in 1909.  It was the first university in England to admit women on the same basis as men.

The University is a major force in the economic, social and cultural life of Bristol and the region, but is also a significant player on the world stage. It has over 16,000 undergraduates and nearly 6,000 postgraduate students from more than 100 countries, and its research links span the globe.

About RTI International

RTI International is an independent, non-profit research institute dedicated to improving the human condition. Clients rely on us to answer questions that demand an objective and multidisciplinary approach—one that integrates expertise across the social and laboratory sciences, engineering, and international development. We believe in the promise of science, and we are inspired every day to deliver on that promise for the good of people, communities, and businesses around the world. For more information, visit www.rti.org