/
Our work /
Projects /
Social Networks and the Hepatitis C Virus

Mitchell Luo S9ertiwswy0 Unsplash Main Image

Social Networks and the Hepatitis C Virus

Past project

Hepatitis C continues to be a major health problem in Australia and is a leading cause of liver failure and liver cancer. In Australia, as well as in other high income countries the vast majority of HCV infections occur in people who inject drugs.

Objective

At the time this work was undertaken there were an estimated 10,000 new HCV infections annually in Australia, with over 85% thought to be due to injecting drug use.

Prevention of HCV transmission is vital to halt an ever-increasing burden of HCV-attributable disease: to do so, we must understand the drivers of transmission and the associated behavioural or immunological factors.

Although some individual-level risk factors for HCV are well known (such as sharing used needles), the population-level phenomena driving HCV transmission are not as well understood.

We had previously shown that hepatitis C risk is dependent on the hepatitis C status of the people within injecting network – more so than on injecting partner numbers or needle-sharing behaviour.

Timeline

2013–2023.

Approach

This work involves over 400 people who contributed blood samples and detailed behavioural and social network data to the Networks study, with over 240 providing multiple blood sample at each encounters (some up to 15) during the four years of data collection.

This longitudinal design of this work was a major strength, because infections can be observed as they occur and their causes become easier to pinpoint.

Community impact

A major outcome of the study was finding that people who had cleared an HCV infection were more likely to acquire a second virus than people who had never been infected.

Another key finding was the network structure played a role in how quickly infection spread with the community.

A key outcome of this work was using the network structure to provide treatment - using a "treat your friends approach" was beneficial in reducing hepatitis C prevalence and incidence (likely by reducing reinfection risk).

The results of this work informed national and global guidelines on approaches to hepatitis C treatment and elimination efforts.