New thesis highlights measures to reduce hepatitis C among people who inject drugs
Caroline Gahrton at the Center for Infectious Medicine (CIM), Clinical Infectious Diseases (CID), at the Department of Medicine, Huddinge (MedH), defends her thesis titled "Hepatitis C in people who inject drugs - prevalence, incidence, mortality, and treatment uptake", on 12 December 2025. Main supervisor is Soo Aleman (MedH).
What is the main focus of your thesis?
The WHO has set the goal of eliminating hepatitis C as a public health threat by 2030. The main transmission route for hepatitis C is sharing injection equipment among people who inject drugs, a group at the highest risk of infection. My thesis includes epidemiological studies of hepatitis C virus infection among people who inject drugs in Sweden, focusing on prevalence, incidence, mortality, and treatment.
Which are the most important results?
We found high liver-related mortality among people who inject drugs and have hepatitis C in Sweden, with the risk particularly pronounced among those injecting amphetamines. The proportion of people with hepatitis C was high both among prison inmates in Stockholm county and participants at the Needle syringe program in Stockholm. When access to treatment increased, we observed that hepatitis C prevalence was halved over time at the Needle syringe program, but there was no significant decrease in incidence. We also showed that more than 80% of all people with hepatitis C in Sweden have been treated, but treatment rates were lower among people who inject drugs.
How can this new knowledge contribute to the improvement of people’s health?
Our research shows that screening for hepatitis C in prisons is crucial to identify infections and enable early treatment. We also demonstrated that increased access to treatment can reduce prevalence among people who inject drugs, but additional measures are needed to decrease transmission. Screening and treatment must be expanded, especially for those with the highest injection risk behaviors, combined with effective harm reduction strategies such as needle syringe programs and opioid substitution therapy. A comprehensive approach is needed to achieve both individual and public health benefits, reduce liver-related mortality, and contribute to the elimination of hepatitis C in Sweden.
What are your future ambitions?
I want to continue developing as an infectious disease physician and researcher while finding a good balance in life that includes clinical work, research, family, and friends.
Dissertation
Friday 12 December 2025, at 9:00, B64, Karolinska University Hospital, Huddinge.
Thesis
Hepatitis C in people who inject drugs - prevalens, incidence, mortality, and treatment uptake