A cross-sectional, nationwide household survey was conducted in Georgia in 2021. Adults aged ≥18 years and children aged 5–17 years were recruited using a stratified, multistage cluster design with systematic sampling. A sample size of 8010 adults and 2692 children was calculated based on an estimated anti–SARS-CoV-2 prevalence of 10%, a design effect of 2, and an anticipated 70% participation rate to produce 95% confidence intervals (95% CI) with a margin of error of 1.1% as well as expected proportion of households with children of applicable age. This calculated sample size was confirmed to produce estimates of HCV infection among adults with a margin of error of 0.67% based on an estimated prevalence of 2.9%. The country was divided into 10 strata across all regions and the capital city of Tbilisi, excluding the separatist regions of Abkhazia and South Ossetia. To reach the target sample size, 267 clusters were selected across the 10 strata, and 30 households were selected per cluster. A household was defined as a group of persons who reside in the same place and prepare meals together. Households were chosen systematically using a skip pattern, and 1 adult and 1 child of eligible age (in households with ≥ 1 child) were selected per household using a Kish grid [8]. An additional 1880 households from 50 clusters in 4 undersampled strata were included for children to account for low initial enrollment. To maximize comparability between the 2015 and 2021 findings, sampling methods were kept as close as possible to those utilized for the 2015 survey and the same statisticians were consulted in the design of both.

Data collection in the field took place during June to October 2021. Individual interviews were administered face-to-face using a structured questionnaire with responses recorded electronically using tablets and uploaded to a cloud-based server (Open Data Kit software application). Participants were asked about their demographic information, medical and behavioral history, and knowledge of hepatitis C. Each participant’s questionnaire was labeled with a unique identifier (barcoded label) that was linked to their blood sample to maintain confidentiality and allow linking of laboratory results and notification to individuals. The hepatitis questionnaire was kept as similar to 2015 as possible to maximize comparability.

Randomly selected members of each household were enrolled for participation after obtaining voluntary informed consent (or parental/legal guardian consent for children aged 5–17 years, paired with assent for children ≥ 7 years of age). Persons with altered mental status precluding consent and any participants who could not give blood because of severe illness or hemophilia were excluded.

Whole venous blood was collected from all participants, with serum separated on site and transported to the Serology Laboratory, Lugar Center for Public Health Research, NCDC for testing. All samples were tested for anti-HCV by the anti-HCV chemiluminescent microparticle immunoassay on a fully automated ARCHITECT i2000SR analyzer (Abbott Diagnostics). Positive samples were tested for HCV RNA by the Abbott RealTime HCV Assay (Abbott Molecular, Inc) on the Abbott m2000rt System (Abbott). Samples found to be anti-HCV positive and HCV RNA negative were further tested by immunoassay (INNO-LIA HCV Score, in vitro diagnostics, Innogenetics) to confirm the anti-HCV result. Test results were provided to participants within a maximum 6 months after sample collection, and infected individuals were counseled and referred to a local provider for linkage to care.

All analysis was performed in SAS version 9.4. Data were weighted at cluster, household, and individual levels, and adjusted by sex, age, and geographic distribution using 2014 census data to produce nationally representative estimates. Sample weights were computed by taking the inverse probability of selection and then multiplied by the poststratification adjustment by age, sex, and region. Weighted proportions and 95% CIs were calculated and compared with 2015 survey results using χ² test with an α of .05. Variance was calculated using Taylor series linearization. For prevalence comparisons by age groups, 2015 data (collected May to August 2015) were age-adjusted by adding 6 years to participants’ ages. Multivariable analysis was performed using weighted estimates to determine independent risk factors for anti-HCV and HCV RNA positivity, with variables associated in bivariate analysis included in the final model to produce adjusted odds ratios (aOR) after assessing for multicollinearity. For model stability, responses of “I don’t remember/know” were treated as a separate category if they were >10% of all responses.

This study was approved by the ethical committee of Georgia’s NCDC and was determined by US CDC’s Human Subjects Research Office to be public health surveillance and therefore judged to not involve human subjects research.

In total, 8710 individuals participated in the survey, including 7237 adults (90.3% participation rate) and 1473 children (72.2% participation rate). After weighting the results according to the age, sex, and regional distributions in the 2014 Georgian census, among adults, the median age was 46 years (interquartile range [IQR], 32–61 years), 53.3% (95% CI, 51.3%–55.2%) were female, and 31.8% (95% CI, 30.6%–33.0%) lived in Tbilisi (Table 1). Overall, 90.7% (95% CI, 87.7%–93.1%) of adults were of Georgian ethnicity, a plurality (42.2%; 95% CI, 39.8%–44.6%) completed university or higher education, and 18.9% (95% CI, 17.4%–20.6%) were unemployed. Among children, the median age was 10 years (IQR, 7–13 years), 52.3% (95% CI, 48.8%–55.8%) were male, and 33.0% (95% CI, 30.5%–35.6%) lived in Tbilisi.

The overall adult prevalence of anti-HCV in 2021 was 6.8% (95% CI, 5.9%–7.7%). Anti-HCV positivity differed by age, with the highest prevalence among those aged 40–49 years (11.5%; 95% CI, 8.8%–14.8%) and 50–59 years (10.7%; 95% CI, 8.5%–13.3%) and lowest among those aged 18–29 years (1.7%; 95% CI, .7%–3.8%) (P < .001) (Table 2). Anti-HCV prevalence was higher among men (11.1%; 95% CI, 9.4%–13.1%) than women (3.0%; 95% CI, 2.4%–3.7%) (P < .001) and varied by region with a high of 8.9% (95% CI, 6.2%–12.7%) in Guria (Western Georgia) and a low of 2.9% (95% CI, 1.7%–4.9%) in Mtskheta-Mtianeti (Eastern Georgia) (P = .02). Unemployed persons had a higher prevalence (13.4%; 95% CI, 10.8%–16.3%) than those who were employed, retired, a student, or homemaker (5.3%; 95% CI, 4.5%–6.2%).

Among adults, the overall HCV RNA prevalence in 2021 was 1.8% (95% CI, 1.3%–2.4%), which differed among men (3.1%; 95% CI, 2.1%–4.4%) and women (0.6%; 95% CI, .4%–1.0%) (P < .001). Among all infected persons, injection drug use (IDU) was reported by 29.9% (95% CI, 17.5%–46.2%), an additional 8.5% (95% CI, 3.9%–17.7%) received a blood transfusion, and 13.4% (95% CI, 6.2%–26.5%) had neither exposure but reported > 5 sex partners. The remaining 48.2% (95% CI, 33.3%–63.4%) reported none of these risk factors for HCV infection.

In bivariate analysis, HCV RNA positivity was associated with unemployment (P = .005), history of IDU (P < .001), past incarceration (P < .001), receipt of a blood transfusion (P = .03) or permanent tattoo (P < .001), number of lifetime sex partners (P < .001), and provider of last therapeutic injection (P < .001). After adjusting for all covariates associated with HCV RNA in bivariate analysis, ever injecting drugs (aOR, 3.09; 95% CI, 1.11–8.56), receipt of a blood transfusion (aOR, 3.10; 95% CI, 1.29–7.48), and having > 5 versus 1–5 lifetime sex partners (aOR, 3.14; 95% CI, 1.05–9.46) remained significantly associated with HCV infection (Table 3). Anti-HCV positivity was associated in a multivariable model with being unemployed (aOR, 1.7; 95% CI, 1.2–2.5), ever injecting drugs (aOR, 26.8; 95% CI, 12.5–57.4), receipt of a blood transfusion (aOR, 4.5; 95% CI, 2.9–7.1), and having 0 versus 1–5 lifetime sex partners (aOR, 0.3; 95% CI, .1–.9).

No children in the sample (n = 1473) tested positive for anti-HCV or HCV RNA.

The prevalence of anti-HCV was not significantly different from 2015 (7.7%; 95% CI, 6.6%–8.8%; P = .20). However, HCV RNA prevalence decreased substantially (from 5.4% [95% CI, 4.5%–6.3%] to 1.8% [95% CI, 1.3%–2.4%]; P < .001). This represents a 67% (95% CI, 46.7%–79.4%) reduction in persons with chronic HCV infection, after the HCV elimination program had treated 51% (n = 76 644) of the 2015 estimate of 150 000 (95% CI, 128 000–173 000) infected. These findings were also observed at the regional level, with no significant changes in anti-HCV prevalence, but HCV RNA prevalence reductions from 47% to 85% (Supplementary Table 1). Prevalence of chronic HCV infection decreased significantly among adults aged 40–49 years (from 9.8% [95% CI, 7.4%–12.9%] in 2015 to 2.7% [95% CI, 1.6%–4.7%] in 2021; P < .001), 50–59 years (from 8.7% [95% CI, 6.5%–11.7%] to 1.6% [95% CI, .9%–3.0%]; P < .001), and ≥60 years (from 3.8% [95% CI, 2.9%–5.2%] to 2.0% [95% CI, 1.1%–3.4%]; P = .02) (Figure 1). Substantial decreases were observed for both men (from 9.0% [95% CI, 7.5%–10.9%] to 3.1% [95% CI, 2.1%–4.4%]) and women (from 2.2% [95% CI, 1.6%–3.0%] to 0.6% [95% CI, .4%–1.0%]) (both P < .001).

Independent risk factors for exposure to hepatitis C in 2015 included history of IDU and receipt of a blood transfusion. Both risk factors were reported less frequently in 2021: the proportion reporting ever injecting drugs decreased from 4.2% (95% CI, 3.4%–5.1%) in 2015% to 3.0% (95% CI, 2.3%–3.9%) in 2021 (P = .03), and blood transfusions decreased from 7.0% (95% CI, 6.1%–7.8%) to 4.7% (95% CI, 3.9%–5.5%) (P < .001). Among those reporting these risk factors, the proportion with chronic HCV infection also decreased substantially, from 51.1% (95% CI, 41.8%–60.3%) to 17.8% (95% CI, 10.5%–28.6%) among persons who ever injected drugs and 13.1% (95% CI, 8.9%–18.9%) to 3.8% (95% CI, 2.0%–7.4%) among those who received a blood transfusion (Figure 2). Although not independent risk factors in multivariable analysis, a significant prevalence decrease was observed in bivariate analysis for those with other established risk factors of past incarceration (32.2% [95% CI, 23.8%–42.0%] to 14.6% [95% CI, 7.9%–25.2%]; P = .01) and surgery (5.3% [95% CI, 4.2%–6.6%] to 2.2% [95% CI, 1.5%–3.1%]; P < .001).

Overall, 66.1% (95% CI, 63.9%–68.2%) reported ever having heard of the hepatitis C virus in 2021, a decline from 73.0% (95% CI, 71.1%–74.9%) in 2015 (P < .001). Among those who had heard of the virus, a higher proportion in 2021 knew it could be cured with medications (77.2% [95% CI, 75.1%–79.2%] vs 70.5% [95% CI, 68.5%–72.6%]; P < .001) and could be transmitted through blood (91.6% [95% CI, 90.2%–92.9%) vs 77.0% [95% CI, 74.8%–79.1%]; P < .001). However, a lower proportion in 2021 correctly identified sharing needles or syringes as a transmission route for HCV infection (54.3% [95% CI, 50.5%–58.0%] vs 71.7% [95% CI, 69.5%–74.0%]; P < .001). Among those who tested HCV RNA positive, 33.1% (95% CI, 21.8%–46.8%) reported having previously been told by a health care provider of their HCV infection.