Investigating the Impact of Scaling-Up Screening, Treatment, and Prevention Interventions Targeting Priority Groups for Hepatitis C Virus Elimination in Pakistan


Author: Lim AG, Walker JG, Qureshi H, Mahmood H, Hamid S, Davies CF, Trickey A, Glass N, Saeed Q, Fraser H, Mukandavire C, Hickman M, Martin NK ,May MT, Averhoff F, Vickerman P

Theme: Epidemiology & Public Health Research Year: 2017

Background:
Pakistan has the second-largest hepatitis C virus (HCV) burden worldwide. Despite increasing access to highly effective direct-acting antiviral (DAA) HCV treatment, low diagnosis and referral rates present challenges to treatment scale-up to reach the World Health Organization (WHO) elimination targets of reducing HCV incidence by 90% and HCV-related mortality by 65% by 2030.

Methods:
We developed a dynamic HCV transmission model for Pakistan incorporating screening and treatment, and calibrated to HCV sero-prevalence data from a national survey in 2007 (4.8%), surveys among people who inject drugs (PWID, 56-69%), and HCV prevalence trends between 1994-2014 from blood-donor data. At baseline we assumed current global average referral rates (7% of HCV-diagnosed patients initiate treatment). We projected HCV-burden, including incidence, prevalence, and mortality through 2030, and estimated the impact of screening, DAA-treatment, and prevention interventions to achieve WHO HCV-elimination targets.

Results:
At current referral rates, general population screening at 15% annually (~31 million individuals tested each year) will result in 320,000 annual treatments, with 4 infections averted-per-1000 antibody screenings (IA/1000Ab), and 430-per-1000 treatments (IA/1000T), leading to a modest 21% reduction in incidence, and mortality rising by 13% from 2016-2030.

Maintaining screening numbers, but scaling-up referral rates to 50% will double treatment numbers (660,000 treatments/year), triple infections averted-per-screening (13 IA/1000Ab), increase infections averted-per-treatment by 35% (580 IA/1000T), and reduce incidence by 74% and mortality by 49% from 2016-2030.

Lastly, if screening also covers 80% of PWID and prevention interventions halve PWID-related transmission risk, then HCV-incidence will decrease by 89% and mortality by 52% – close to achieving the elimination targets. This intervention requires fewer treatments (620,000/year), with more infections averted-per-screening (15 IA/1000Ab) and per-treatment (770 IA/1000T).

Conclusion:
Substantial scale-up of screening, referral, treatment, and prevention interventions, especially targeting priority groups such as PWID, are required to maximise impact and achieve WHO-HCV elimination in Pakistan.

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