FAQs

What data are available on HepVu?

HepVu maps state-level Hepatitis C prevalence estimates from 2013 to 2016, stratified by age, sex, and race. Prevalence estimates were obtained from the Emory University Coalition for Applied Modeling for Prevention (CAMP) project, including researchers from the University at Albany, and stratified prevalence estimates were developed by researchers at Georgia State University, Emory University, CDC, and the University at Albany. Both publications were collaborative efforts with researchers from the Centers for Disease Control and Prevention (CDC). Original prevalence estimates were published in the Journal of the American Medical Association (JAMA) Network Open and stratified estimates were published in Hepatology Communications.

HepVu also maps Hepatitis C-related mortality data (2020 for counties, 2021 for states) and three opioid-related indicators that, together with HepVu’s Hepatitis C data, help illustrate the relationship between the opioid crisis and viral hepatitis in the U.S. The opioid-related data on HepVu include:

• Opioid prescription rate (2021)
• Overdose mortality rate (2021)
• Pain reliever misuse percent (2021)

HepVu’s Hepatitis C data can be visualized by rates and cases, by age, sex, and race, and alongside data comparison maps, including geographic comparisons, opioid-related indicators, and social determinants of health such as poverty, high school education, median household income, income inequality, and people without health insurance.

What do the data on HepVu reveal about Hepatitis C in the U.S.?

The data on HepVu show an estimated 4 million people living with Hepatitis C infection in the U.S. between 2017 and 2020, with a high burden in the West and in some Appalachian states. The data illustrate that the Hepatitis C epidemic continues to disproportionately impact males, those born between 1945 and 1969, Black Americans, and, increasingly, young persons in states highly affected by the opioid epidemic – a result of injection drug use.

Do you intend to update the data presented on HepVu?

HepVu will continue to add new data and features as they become available in the future, including additional opioid indicators and annually-updated mortality data. Other information, such as expert Q&A blogs and infographics, are frequently published on HepVu’s site and social media channels.

Why does HepVu primarily focus on Hepatitis C?

Visualizing the Hepatitis C epidemic is one of HepVu’s core areas of focus because it is one of the leading causes of liver-related death and illness in the U.S. According to CDC, the number of Hepatitis C-related deaths in 2013 was greater than the combined number of deaths from 60 other infectious diseases, including HIV and tuberculosis. More than half of those infected with Hepatitis C are not aware of their status. However, Hepatitis C is curable, making it especially important to use data to understand where additional screening, treatment, and prevention resources may be needed. Improving our understanding of the epidemic’s extent and geographic variations, as well as how it impacts different populations, can inform policy, programmatic, and resource planning for elimination strategies across the U.S.

Surveillance of all types of hepatitis is limited by a lack of comprehensive data due to limited resources and investment in standardized surveillance and variability in how states monitor hepatitis infections. At present, the best available hepatitis data pertains to Hepatitis C. HepVu currently provides infographics on Hepatitis A and B and is investigating opportunities to visualize Hepatitis A and B data in the future.

What is the difference between Hepatitis A, B, and C?

Please visit HepVu’s Hepatitis ABC’s page to learn more about the different forms of hepatitis.

Where does the HepVu data come from?

The state-level Hepatitis C prevalence estimates displayed on HepVu were produced from the Emory University Coalition for Applied Modeling for Prevention (CAMP) project, including researchers from the University at Albany, and were developed in collaboration with the Centers for Disease Control and Prevention (CDC). Findings were published in the Journal of the American Medical Association (JAMA) Network Open in the paper, “Prevalence of Hepatitis C Virus Infection, US States and District of Columbia, 2013 – 2016.”

Building on this methodology, the state-level stratifications of Hepatitis C prevalence by age, sex, and race were developed by researchers at Georgia State University, Emory University, CDC, and the University at Albany and published in Hepatology Communications in the paper, “Hepatitis C virus prevalence in 50 U.S. states and D.C. by sex, birth cohort, and race: 2013–2016.”

State-level Hepatitis C-related mortality data were obtained from the WONDER online database system developed by CDC. State-level opioid indicators were sourced from CDC, the U.S. Census, and the Substance Abuse and Mental Health Services Administration (SAMHSA).

County-level Hepatitis C-related mortality data were obtained from the National Center for Health Statistics and compiled by researchers at the Rollins School of Public Health at Emory University. Validated algorithms were utilized to estimate Hepatitis C-related death rates at the county-level, and by age. The method to calculate these estimates can be referenced via Hall et al.’s published article in Hepatology titled “County-Level Variation in Hepatitis C Virus Mortality and Trends in the United States, 2005-2017.”

All data were compiled by researchers at the Rollins School of Public Health at Emory University. More information on the data sources can be found on the Data Methods page.

How is HepVu data different than other sources or what my state reports?

One of the most critical challenges in our national response to viral hepatitis is limited data that could help us understand and monitor the epidemic. HepVu attempts to close this gap by providing a standardized, state-by-state look at Hepatitis C in the U.S. The site also examines the critical role of the opioid epidemic and its impact on hepatitis and other blood-borne viruses.

All data available on HepVu are derived from systematic, high-quality, public data sources, and the Hepatitis C prevalence data and stratified estimates were developed in collaboration with CDC researchers. The data are peer-reviewed and publicly available, which differentiates HepVu from other sources of information on hepatitis – some of which may contain overlapping but not de-duplicated datasets and provide limited information on the origins of the data. Additionally, because the estimates on HepVu are largely based on blood test results from a household survey, they include both undiagnosed and diagnosed Hepatitis C infections.

Many states have their own unique methods for quantifying the number of Hepatitis C infections in their state. Methods based on locally available surveillance data may generate different results. As a result of the variability in approaches and data sources among individual states, it is difficult to compare results across jurisdictions. However, the systematic nature of the prevalence estimates and other data on HepVu provide an opportunity to quantify and compare the Hepatitis C epidemic across all 50 states and Washington, D.C.

How were the Hepatitis C prevalence estimates on HepVu generated?

The state-level Hepatitis C prevalence estimates displayed on HepVu are derived using an updated approach to the previously published methodology for 2010 state-specific Hepatitis C prevalence estimation that reflects current changes to the epidemic. To estimate state-level Hepatitis C prevalence, researchers analyzed blood test results from the nationally representative National Health and Nutrition Examination Survey (NHANES) and vital statistics data from 2013 through 2016, and incorporated data on Hepatitis C-related deaths and narcotic overdose deaths.

The researchers also estimated the number of Hepatitis C infections among populations not included in NHANES, including incarcerated, unsheltered homeless, and nursing home resident populations. These populations were calculated using a systematic literature review of articles published between 2013 and 2017, as well as other public data sources.

The state-level Hepatitis C prevalence stratifications by age, sex, and race were based on this methodology and additionally show how the previously mapped estimates of Hepatitis C infections by state are distributed by sex, age, and race.

Why are the Hepatitis C prevalence estimates from 2013-2016?

The most current NHANES Hepatitis C data are from 2016, but combining multiple years of data provides more information and increases the accuracy of estimates. The data on HepVu combined four years of data to develop the prevalence estimates and stratifications, and increase the robustness of the model.

Updated data from 2017-2020 was recently published in Hepatology: “Estimating hepatitis C prevalence in the United States, 2017-2020″ by HepVu Project Director Dr. Heather Bradley and HepVu Fellow Dr. Eric Hall, with CDC coauthors.

Why does HepVu state that 4 million people are living with Hepatitis C?

When accounting for increased injection drug use, estimated prevalence of Hepatitis C is substantially higher than previously reported.

Updated data from 2017-2020 was recently published in Hepatology: “Estimating hepatitis C prevalence in the United States, 2017-2020″ by HepVu Project Director Dr. Heather Bradley and HepVu Fellow Dr. Eric Hall, with CDC coauthors. This research found that when previous estimates were adjusted to account for underrepresentation of PWID in NHANES by incorporating the estimated number of adult PWID and PWID-specific hepatitis C prevalence estimates, the estimated number of people living with Hepatitis C in the U.S. is approximately 4 million.

Can I compare the 2013-2016 Hepatitis C prevalence estimates to the 2010 estimates?

No. The previously published methodology for 2010 state-specific Hepatitis C prevalence estimation was updated to derive the 2013-2016 estimates currently displayed on HepVu. While the basis of each model is NHANES, a number of other data sources were incorporated into the 2013-2016 modeling process to reflect current changes to the epidemic, including narcotic overdose mortality. Given the additional data sources used for 2013–2016 estimates, findings from the two data models are not comparable.

Why do stratified estimates differ from the total number of Hepatitis C infections in individual states?

In some cases, the sum of the stratified estimates may be higher or lower than the overall estimated number of Hepatitis C infections for a state. For example, the estimated numbers of infections among males and females in a given state may, together, be higher than the estimated number of infections for that state. These apparent inconsistencies may happen because – to increase accuracy of the estimates by demographic characteristics – the model used for the stratified estimates includes more granular information on demographic groups by state and thus may yield slightly different results.

What is a model and how was it used to create the Hepatitis C prevalence estimates?

A model is a mathematical process that aims to predict or describe the dynamics in a system as accurately as possible using collected information (i.e., data). This particular approach uses a model to predict Hepatitis C prevalence in U.S. states using data from multiple sources: NHANES, the U.S. Census, and data on Hepatitis C-related deaths and narcotic overdose deaths.

Why does the map differ between rate and number of cases?

The scales in the legends for Hepatitis C-related mortality rates and cases differ because the rate (expressed as the number of cases per 100,000 people in the population) is an expression of the relative concentration of estimated deaths related to Hepatitis C in a state. The number of cases is the number of estimated deaths that occurred in people who had Hepatitis C. The rates can be useful for comparing the severity of the Hepatitis C epidemic in areas with different population sizes – such as comparing densely populated areas to a more sparsely populated one. The number of cases can identify areas where the greatest or fewest number of Hepatitis C-related deaths have occurred.

For example, in a state with fewer people but with a relatively large number of deaths related to Hepatitis C, the state may be shaded a dark purple when viewing the mortality rate. However, the same state may not appear dark purple when viewing the map by the total number of cases because the state has a smaller number of cases compared to other states.

Where can I get more information about the methods for the 2013-2016 Hepatitis C prevalence estimates and stratifications?

Findings were published in the Journal of the American Medical Association (JAMA) Network Open in the paper, “Prevalence of Hepatitis C Virus Infection, US States and District of Columbia, 2013 – 2016.” The paper and descriptions of the methodology can be viewed here. Additionally, stratified estimates were published in Hepatology Communications in the paper, “Hepatitis C virus prevalence in 50 U.S. states and D.C. by sex, birth cohort, and race: 2013–2016” and can be found here.

How is Hepatitis C-related mortality defined and why is it important?

The Hepatitis C-related mortality data on HepVu is defined as deaths attributable to the Hepatitis C virus. Since Hepatitis C can lead to severe liver damage, liver cancer, and even death if not detected and treated, strategic plans by Centers for Disease Control and Prevention (CDC) and the Department of Health and Human Services (HHS) have specifically identified reducing the national Hepatitis C-related death rate as an indicator to monitor progress toward achieving elimination.

Data from the National Vital Statistics System indicate the national Hepatitis C-related death rate has declined since 2013. However, there have been shifts in the Hepatitis C epidemic, advancement in treatment options, and changes in public health strategies–all of which are likely to impact Hepatitis C-related mortality.

Although the national Hepatitis C-related death rate has declined since 2013, and Hepatitis C-related mortality is still disproportionately concentrated among persons born 1945 through 1965, Hepatitis C-related mortality in several places around the country is increasing among adults younger than 40 years of age. Many of the counties with the highest death rates for this younger age group are concentrated in Appalachia and parts of the Southwest. These areas have also experienced increases in injection drug use (IDU) and rising viral hepatitis incidence rates.

These findings demonstrate that Hepatitis C is still a significant health problem in our country.

HepVu’s county-level opioid prescription and overdose mortality rates data were originally calculated in a study published in Drug and Alcohol Dependence.

What Hepatitis C-related mortality data does HepVu map?

HepVu maps Hepatitis C-related mortality at the state- and county-level. State-level Hepatitis C-related mortality can be viewed as the number of Hepatitis C-related deaths or the rate of Hepatitis C-related deaths, expressed as the number of deaths per 100,000 people in the population. The data is broken down by age (year of birth, displayed as less than 50, 50 to 74, 75+), sex (sex at birth, displayed as male or female), and race (displayed as American Indian or Alaska Native, Asian or Pacific Islander, Black, Hispanic/Latinx, White).

County-level Hepatitis C-related mortality on HepVu are model-based estimates and can be viewed as rate of Hepatitis C-related deaths expressed as the number of deaths per 100,000 people in the population. The data is broken down by age (year of birth, displayed as less than 40 or 40+). At present, HepVu is not able to provide county-level Hepatitis C-related mortality by race/ethnicity and sex.

Data on county- and state-level Hepatitis C-related mortality can also be viewed alongside social determinants of health, such as poverty, high school education, median household income, income inequality, and people without health insurance.

Why are some counties missing Hepatitis C-related mortality data?

Data suppression rules were applied because the data are model-based estimates, and some county-level rates were defined as unreliable. If a county had an unreliable Hepatitis C-related death rate, estimated rates for that county during that year were not reported. Additionally, if a county had an unreliable rate for either age group, both age-stratified rates were suppressed for that county during that year.

Please see the Data Methods page for additional information about data suppression rules.

What is the source of HepVu’s Hepatitis C-related mortality data?

State-level Hepatitis C-related mortality data presented on HepVu were obtained from the CDC WONDER Online Database System and compiled by researchers at the Rollins School of Public Health at Emory University. The CDC WONDER data are collected using information from death certificates of all U.S. residents within the 50 states and Washington, DC.

County-level Hepatitis C-related mortality data were obtained from the National Center for Health Statistics and compiled by researchers at the Rollins School of Public Health at Emory University. Validated algorithms were utilized to estimate Hepatitis C-related death rates at the county-level, and by age. The method can be referenced in Hall et al.’s published article in Hepatology titled “County-Level Variation in Hepatitis C Virus Mortality and Trends in the United States, 2005-2017.”

Please see the Data Methods page for additional information.

What does HepVu’s Hepatitis C-related mortality data reveal?

• In 2021, the highest rates of Hepatitis C-related mortality were primarily concentrated in the South and West.

• In 2020, the top 10 counties with the highest rates Hepatitis C Mortality were in the South.

Why are HepVu’s state- and county-level Hepatitis C-related mortality data sources different?

Although data from the National Vital Statistics System indicate the national Hepatitis C-related death rate has declined since 2013, there has not been, until recently, a study to look at trends in Hepatitis C-related mortality at local levels. While public health workers often look at national- and state-level data to guide policy decisions and evaluate trends, it’s important to recognize that national- or state-level data is an average of what’s occurring in smaller geographic areas, such as counties. National- and state-level data are important because they provide a high-level perspective of disease burden and trends, but they can also mask differences or disparities that might be occurring at local levels.

Because public health initiatives are implemented at local levels, removing that mask and uncovering those differences gives us a more detailed understanding of the viral hepatitis epidemic across the country. This detailed picture is important in determining where to allocate funding and resources to reduce Hepatitis C-related mortality.

In order to achieve a more granular view of Hepatitis C-related mortality, researchers at Emory University utilized data from the National Vital Statistics Systems to gather individual line level data and analyze it by groups at the county-level.

Although these findings do not replace the need for a comprehensive and cohesive viral hepatitis surveillance system, these county-level data on Hepatitis C-related mortality provide an important metric for understanding the evolution of the Hepatitis C epidemic.

Can I compare HepVu’s state- and county-level Hepatitis C-related mortality data and maps?

Hepatitis C-related mortality data and maps at the county-level are not meant to be compared to the state-level Hepatitis C-related mortality data and maps. Because the county-level data are model-based estimates and the state-level data are reported rates, the data should not be compared across different geographic levels. County-level Hepatitis C-related mortality rates are meant to be compared to mortality rates in other counties, whether in the same state or elsewhere.

How can HepVu’s Hepatitis C-related mortality data and resources be used?

Local jurisdictions can use these data to better understand how Hepatitis C-related mortality in their region compares to surrounding areas or to the entire nation. A better understanding of where high Hepatitis C-related mortality is occurring can inform the allocation of public health resources and interventions that aim to reduce Hepatitis C-related mortality or infection.

County- and state-level Hepatitis C-related mortality data on HepVu can also be viewed alongside social determinants of health, such as poverty, high school education, median household income, income inequality, and people without health insurance. Additionally, HepVu provides downloadable data sets at the county- and state-level for researchers and health departments to utilize in their own analyses.

Why does HepVu feature data and information about the opioid epidemic in the U.S.?

Hepatitis C and other infectious diseases are often-overlooked consequences of America’s opioid crisis. As the opioid epidemic continues to significantly impact communities in the U.S., new blood-borne virus infections related to drug use, including hepatitis and HIV, are concerning. Though Hepatitis C has primarily impacted those born between 1945 and 1965 in the past, the largest increases in Hepatitis C infections over the last decade have been among individuals less than 40 years old. This is due in part to the increasing misuse of opioids and, in turn, the sharing of needles and other equipment used to inject drugs.

HepVu believes it is critical to understand this syndemic to highlight the causal connection between the increases in opioid use and blood-borne viruses, particularly Hepatitis C, in order to inform public health decision-making and raise greater awareness about the infectious disease consequences of the opioid epidemic.

To learn more, please visit our Deeper Look: Opioids page.

What do each of the opioid indicators show?

HepVu currently visualizes three state-level opioid indicators. The first, opioid prescription rate, shows retail opioid prescriptions dispensed per 100 people in each county in 2021, as well as each state in 2021. State-level data were sourced from CDC and the county-level data were originally calculated in a study published in Drug and Alcohol Dependence.

The second, overdose mortality rate, shows the number of overdose-related deaths per 100,000 people in each county in 2021 and each state in 2021. These data were sourced from CDC WONDER and the U.S. Census , and the county-level data were originally calculated in a study published in Drug and Alcohol Dependence.

The third is misuse of pain relievers prevalence, which shows the percentage of persons misusing prescription pain relievers in each state. These data represent the 2021 year average and were sourced from the Substance Abuse and Mental Health Services Administration (SAMHSA), a branch of the U.S. Department of Health and Human Services.