Objective:

To explore how COVID-19 pandemic-related service disruptions and behavioral changes affected the transmission of HCV and HIV among people who inject drugs (PWID), emphasizing the implications for public health.

Key Findings:

• Injection cessation increased overall during the pandemic, but those who continued injecting did so more frequently, raising concerns for public health.
• Drug-use networks among PWID became smaller, reducing the likelihood of injecting with others, which may have implications for transmission dynamics.
• HCV and HIV prevalence increased due to service disruptions, but this was mitigated by behavioral changes among PWID, suggesting a complex interaction between service access and individual behavior.

Interpretation:

Pandemic-induced behavioral changes among PWID may have offset the increased disease burden from disrupted health services, highlighting the importance of understanding individual behaviors in disease transmission dynamics and their potential long-term effects.

Limitations:

• Potential underascertainment of HCV and HIV diagnoses during the pandemic, which could lead to an underestimation of the true disease burden.
• Models may have underestimated the impact of behavioral changes on transmission dynamics, affecting the reliability of the findings.

Conclusion:

The study emphasizes the need to consider both service disruptions and behavioral shifts in understanding HCV and HIV transmission among PWID during the COVID-19 pandemic.