Characterizing the temporal evolution of the hepatitis C virus epidemic in Pakistan.

Pakistan has the second largest number of HCV infections in the world. We assessed past, present and future levels and trends of the HCV epidemic in Pakistan. An age-structured mathematical model was developed and analysed to describe transmission dynamics over 1980-2050. The model was fitted to a nationally representative survey and a comprehensive database of systematically gathered HCV Ab prevalence data. HCV Ab and chronic infection prevalences peaked at 5.3% and 3.9% in 2000 but were projected to decline to 4.3% and 3.2% by 2017, 3.4% and 2.6% by 2030 and 2.6% and 1.9% by 2050, respectively. The number of chronically infected individuals was estimated at 6 663 906 in 2017 and was projected to peak at 6 665 900 in 2018 and decline to 6 372 100 in 2030 and 5 131 500 in 2050. Annual number of new infections peaked at 346 740 in 1992 but was projected to decline to 198 320 in 2017, 151 090 in 2030 and 98 120 in 2050. Incidence rate per 100 000 person-year peaked at 343 in 1988 but was projected to decline to 99 in 2017, 62 in 2030 and 36 in 2050. Prevalence and incidence varied by age, and the majority of new infections occurred in the 20-39 age group. Prevalence and incidence of HCV in Pakistan have been slowly declining for two decades-Pakistan is enduring a large epidemic that will persist for decades if not controlled. Nearly, 10% of global infections are in Pakistan, with about 200 000 additional infections every year. Rapid and mass scale-up of prevention and treatment programmes are critically needed.