# Presentation: 312147

## Epidemiology of HCV in the United States:The HepCAT Project

**Cindy Weinbaum, MD, MPH**
- Division of Viral Hepatitis
- Centers for Disease Control and Prevention

***"The findings and conclusions in this presentation are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention."***

**Features of HCV Infection**

- Incubation period	Average, 6–7 wk	Range, 2–26 wk
- Acute illness (jaundice)	Mild (20%–30%)
- Persistent infection	75%–85%
- Chronic hepatitis	70%
- Immunity	No protective antibody	response identified

## Risk of Fatal Outcome in Persons Who Develop HCV

- Cirrhosis17

- Chronic85

**Risk of Fatal Outcome in Persons Who Develop HCV**

- Courtesy of Seeff, LB and Alter, HJ.

- Time

- 100

- Resolve15

- Stable68

- Stable13

- Mortality4

- 80%

- 20%

- 75%

- 25%

- 15%

- 85%

## Incidence of Acute HCV Infection, United States

## Etiology of Chronic Liver Disease in Three Health Care Systems*, 1999-2000

- Hepatitis C
- 42%

- HCV &
- Alcohol-Related
- Liver Disease
- 22%

- Alcohol-Related
- Liver Disease
- 8%

- Non-Alcoholic
- Fatty Liver
- Disease
- 9%

- Other
- 7%

- Etiology
- Undetermined
- 9%

- Hepatitis B
- 3%

**Etiology of Chronic Liver Disease in Three Health Care Systems*, 1999-2000**

- Bell, et al. *Am J Gastroenterol; *2008, in press. *New Haven County CT, Multnomah County OR, and
- Kaiser Permanente in Alameda County CA

## Prevalence of Anti-HCV, United States, 1999-2002 (NHANES)

- Armstrong, et al, *Ann Intern Med.* 2006;144:705-714.

**Overall prevalence:  1.6% (4.1 million)**

## Prevalence of HCV RNA by Ageand Race, United States, 1999-2002

- Armstrong, et al, *Ann Intern Med.* 2006;144:705-714.

## Relative Importance of Risk Factors for Remote and Recent HCV Infection

**Remote (>~20 yrs ago)**

- Transfusion

- Sexual

- Other*

- Unknown

- Transfusion

- Injection Drug Use

- Unknown

- Other*

- Sexual

- Injection Drug Use

**Recent (<~20 yrs ago)**

**Relative Importance of Risk Factors for Remote and Recent HCV Infection**

## Risk of HCV Infection Among Injection Drug Users

- Garfein RS *Am J Public Health* 1996; 86:655;  Thorpe LE *JID* 2000;182:1588-94; Diaz T *Am J Public Health* 2001; 91(1): 23-30.

**Baltimore: 1983-1988**

**Chicago: 1997-99**

**NY - Harlem: 1997-99**

**NY – LES: 1997-99**

## Figure 1. Prevalence of hepatitis C virus antibody (Anti-HCV) and duration of injection by site, race, and study. Red lines, Collaborative Injection Drug User Study (CIDUS) I, 1994–1996. Blue lines, CIDUS II, 1997–1999. Green lines, CIDUS III, 2002–2004. LA, Los Angeles; NYC, New York City. From Clinical Infectious Diseases 46(12):1852–1858.

## Relative Importance of Risk Factors for Remote and Recent HCV Infection

**Remote (>~20 yrs ago)**

- Transfusion

- Sexual

- Other*

- Unknown

- Transfusion

- Injection Drug Use

- Unknown

- Other*

- Sexual

- Injection Drug Use

**Recent (<~20 yrs ago)**

**Relative Importance of Risk Factors for Remote and Recent HCV Infection**

## Sexual Transmission of HCV

- Case-control, cross sectional studies
- infected partner, multiple partners, early sex, non-use of condoms, other STDs, sex with trauma
- MSM no higher risk than heterosexuals
- Partner studies
- low prevalence (1.5%) among long-term partners
- infections might be due to common percutaneous exposures (e.g., unsafe injections, drug use)
- male to female transmission more efficient
- more indicative of sexual transmission

## Sexual Transmission of HCV- II

- Occurs, but efficiency is low
- Rare between long-term steady partners
- Factors that facilitate transmission between partners unknown (e.g., viral titer, other STDs)
- Accounts for 15-20% of acute and chronic infections in the United States
- Sex is a common behavior
- Large chronic reservoir provides multiple opportunities for exposure to potentially infectious partners

## Relative Importance of Risk Factors for Remote and Recent HCV Infection

**Remote (>~20 yrs ago)**

- Transfusion

- Sexual

- Other*

- Unknown

- Transfusion

- Injection Drug Use

- Unknown

- Other*

- Sexual

- Injection Drug Use

**Recent (<~20 yrs ago)**

**Relative Importance of Risk Factors for Remote and Recent HCV Infection**

## Other Potential Exposures to Blood

- No or insufficient data showing increased risk
- intranasal cocaine use, tattooing, body piercing, acupuncture, military service
- Limited number of studies showing associations that cannot be generalized
- convenience or highly selected groups (mostly blood donors)
- No associations in acute case-control or population-based studies

## Other Potential Exposures to Blood - II

- Biologically plausible but no data showing these practices, procedures, or histories alone place persons at increased risk for HCV
- May be limited to certain settings and account for small fraction of cases
- e.g., prisons, unregulated practitioners, populations with certain cultural practices, etc.
- Risk factor or high prevalence identified in selected subgroup cannot be extrapolated to the population

## National HCV Prevention Strategy   

- Prevent HCV infection
- Detect and control chronic liver disease
- Evaluate effectiveness of activities
- Conduct surveillance and research

## Prevention Activities 

**Primary = Prevent HCV Transmission**
- High risk activities – IDU, high risk sex
- Nosocomial, occupational, transfusions and transplant
**Secondary = Reduce Risk of Chronic Liver Disease**
- Identify, test, counsel, medical management

## Reasons to Identify Persons with Chronic HCV Infection 

**Medical management**
**Evaluate for chronic liver disease**
**Treatment if indicated**
**Substance abuse treatment (alcohol, drugs) if appropriate**
**Immunization (HBV, HAV, influenza, pneumonia)    **
**Counsel to prevent disease transmission**
**Household contacts**
**Sexual contacts**
**Drug use contacts**

## HCV Infection - Estimates of Past Incidence and Future Prevalence

**Incidence**

**Infected**
**20+ years**

**Overall prevalence**

**HCV Infection - Estimates of Past Incidence and Future Prevalence**

**Source: Armstrong GL et al. *****Hepatology***** 2000;31**

**Decline in cases among IDUs**

## HCV Testing Routinely Recommended by CDC in 1998

** ****Received clotting factors made before 1987**
** ****Received blood/organs before July 1992 **
** ****Ever on chronic hemodialysis**
** ****Evidence of liver disease**

**HCV Testing Routinely Recommended by CDC in 1998**

***Based on increased risk for infection***

**Recommendations for Prevention and Control of Hepatitis C Virus (HCV) Infection and **
**HCV-Related Chronic Disease.  *****MMWR***** 1998; 47: RR-19 **

## Healthcare, emergency, public safety workers after needle stick/mucosal exposures to HCV-positive blood
Children born to HCV-positive women  

**HCV Testing Routinely Recommended**
**by CDC in 1998**

***Based on need for exposure management***

**Recommendations for Prevention and Control of Hepatitis C Virus (HCV) Infection and HCV-Related Chronic Disease.  MMWR 1998; 47: RR-19 **

- Healthcare, emergency, public safety workers after needle stick/mucosal exposures to HCV-positive blood
- Children born to HCV-positive women

## CDC's Division of Viral Hepatitis

- _[http://www.cdc.gov/hepatitis](http://www.cdc.gov/hepatitis)_
**Cindy Weinbaum, cweinbaum@cdc.gov, 404-718-8542**
**Bryce Smith, bsmith6@cdc.gov, 404-639-6277**