Hepatitis B and C

Variables

  • Newly Reported Past or Present Hepatitis C Infection
  • Newly Reported Chronic Hepatitis B Infection

Overview

  • San Francisco has the highest rate of liver cancer in the country, which is mostly caused by viral hepatitis.
  • Asian and Pacific Islanders (APIs) in San Francisco are disproportionately affected by hepatitis B (HBV), comprising one-third of San Francisco’s population but representing nearly 90 percent of reported cases.
  • Black/African Americans in San Francisco are disproportionately affected by hepatitis C (HCV), comprising almost eight percent of San Francisco’s population but representing over 30 percent of reported cases.
  • Viral hepatitis is a health equity issue; End Hep C SF and SF Hep B Free have emerged as innovative campaigns to increase awareness of HCV and HBV, and ultimately eliminate HCV and HBV as public health threats in San Francisco.

What is it?

Viral hepatitis is an inflammation of the liver caused by a viral infection. Both hepatitis B and hepatitis C are spread through contact with bodily fluids, primarily blood in the case of hepatitis C, and blood and/or sexual fluids in the case of hepatitis B. Hepatitis D infection may coexist with hepatitis B infection.

Hepatitis C: Although 15 to 25 percent of people who contract hepatitis C virus (HCV) clear the virus on their own within six months after infection, most people (75 to 85 percent) who get HCV will develop chronic infection. Currently, sharing needles or other equipment to inject drugs is the main source of HCV infection. HCV can also spread through needle stick injuries or use of unsterile equipment in healthcare settings, through birth from a mother who has hepatitis C, and through blood transfusions and organ transplants (this has rarely occurred in the United States since widespread screening of the blood supply began in 1992). Less commonly, HCV can also be spread through sexual contact with an HCV-infected person or through sharing personal items contaminated with infectious blood. [1]

Hepatitis B: Hepatitis B virus (HBV) causes a liver infection that can range from an acute, mild illness to a serious, lifelong chronic infection. HBV-infected women pass the infection to their babies during the birth process. People can also become infected with HBV by sharing needles for injection drug use; through sexual contact with an infected person; by an accidental needle stick with a contaminated needle; or from improperly sterilized medical, acupuncture, piercing, or tattooing equipment. Ten percent of adults infected with HBV and 90 percent of babies exposed at birth will develop chronic hepatitis B infection. [2] An effective vaccine is available and vaccination against HBV is required for entry into school in California. [3]

 

Why is it important for health?

Hepatitis C: HCV is the most common blood-borne disease, a major cause of liver cancer, and the leading cause of liver transplants in the United States. [4] Approximately 50% of liver cancer cases are attributable to hepatitis C infection.[5] Nationwide an estimated 3.2 million people are infected with HCV, and in California an estimated 750,000 people are living with HCV. Unless current trends are reversed, the deaths due to HCV will double or even triple in the next 20 years. Each year since 2007, more people have died of HCV than of HIV in the United States.[7] While there is no vaccine to prevent hepatitis C, treatment with direct-HCV acting antivirals can cure over 85% of cases. Successful treatment reduces liver cancer risk by 75% and decreases transmission of the virus to others. [6]

Hepatitis B: Nationwide, approximately 15% of liver cancer cases are attributable to HBV infection.[5] HBV affects approximately 240 million people worldwide, and in the United States, an estimated 1.4 million persons have chronic HBV infection. Rates of acute hepatitis B in the United States have declined by approximately 82 percent since 1991, when the Centers for Disease Control and Prevention recommended routine HBV vaccination of children in the United States.[2] Approximately two out of three people who are infected do not know it.[8]

 

What is the status in San Francisco?

Past or Present Hepatitis C Infection:[1] In San Francisco an estimated 12,000 people are living with active hepatitis C [6] and per 100,000 residents, there are more newly reported cases of past or present HCV infection in San Francisco than in California [9]. The burden of HCV in San Francisco mirrors that of the United States in terms of its disproportionate impact amongst Black/African Americans and baby boomers, people born between 1945 and 1965 (Figure 1A, 1B and 1C); Black/African Americans comprise approximately 26.3% of HCV cases, but only 8% of San Francisco’s population, while baby boomers comprise two-thirds of HCV cases but only one quarter of San Francisco’s population. Increased liver cancer rates among Black/African Americans and Latino males and females are likely attributable to hepatitis C infection and obesity. [10]

Chronic Hepatitis B Infection:[2] Chronic hepatitis B virus infection disproportionately affects Asian and Pacific Islander populations in San Francisco, as well as throughout the United States. While comprising one-third of San Francisco’s population, API populations represent an estimated 88 percent of newly reported cases where race is known (Figure 2B). The increased burden in this population is likely attributable to infection among foreign-born API people who came from areas with high (more than 8 percent) and intermediate (2–7 percent) prevalence levels for hepatitis B surface antigen (HBsAg). [11, 12] San Francisco has the highest rate of liver cancer in the United States. [13, 14] API males have rates up to three times higher than males of other ethnicities. High rates of HBV infection among API men is a leading cause of elevated liver cancer rates in API males. [10]

What is currently being done in San Francisco to improve health?

Hepatitis C: The End Hep C SF collective impact initiative was established in 2016 with the ultimate goal of eliminating HCV in San Francisco. End Hep C SF is a collaboration between over 30 community partners, including the SFDPH, and focuses on community-based HCV testing and linkage to care, improving treatment access, and preventing new infections and reinfections, The introduction of direct-acting and highly effective antiviral HCV medications in recent years has provided an opportunity to not only improve health outcomes, but even cure people chronically infected with HCV, thus paving the way to eliminate HCV as a public health threat in San Francisco. [7]

Hepatitis B: The fact that APIs bear the largest burden of chronic HBV infection highlights the need to provide culturally and linguistically appropriate education about HBV prevention throughout the API community. Efforts to raise awareness about HBV prevention and treatment in the API and clinical communities have been undertaken by SF Hep B Free, a citywide campaign that began in 2007 to (1) increase public and healthcare provider awareness of hepatitis B; (2) promote HBV testing and vaccination of all API persons in San Francisco; and (3) ensure access to treatment for the chronically infected individuals. [15]

 

Data Sources

SFDPH Communicable Disease Control and Prevention, San Francisco Department of Public Health (SFDPH).

 

Methods and Limitations

Past or present HCV infection: The 2012 CDC/CSTE laboratory criteria are applied to HCV test results to identify persons who newly meet laboratory criteria for past or present HCV infection. These persons may have acute, chronic, or resolved infection because no single lab test distinguishes acute from chronic HCV infection or chronic infection from resolved infection.

​The CDC laboratory criteria used to identify past or present HCV infection are any one of the following: antibodies to hepatitis C virus (anti-HCV) screening test positive with a signal-to-cutoff ratio predictive of a true positive as determined for the particular assay as defined by CDC or hepatitis C virus recombinant immunoblot assay (HCV RIBA) positive or nucleic acid test (NAT) for HCV RNA positive (including qualitative, quantitative, or genotype testing). For the signal-to-cutoff ratios, see http://www.cdc.gov/hepatitis/HCV/LabTesting.htm.

Chronic hepatitis B: The 2012 CDC/CSTE laboratory criteria for diagnosis are applied to HBV test results to identify persons with probable and/or confirmed chronic hepatitis B. CDC defines a probable case of chronic hepatitis B as a person who has a single positive hepatitis B surface antigen (HBsAg), positive HBV DNA, or positive hepatitis Be antigen (HBeAg) lab result and who does not meet the case definition for acute hepatitis B. A confirmed case of chronic hepatitis B is a person who has a single positive HBsAg, positive HBV DNA, or positive HBeAg lab result and a negative IgM anti-HBc lab result, OR who tests positive for HBsAg, HBV DNA, or HBeAg two times at least six months apart.

Surveillance data do not measure prevalence: The data presented are not an estimate of the incidence or prevalence of chronic hepatitis B or of past or present HCV infection in San Francisco residents.

 

References

[1] Centers for Disease Control and Prevention. Viral hepatitis — hepatitis c information. http://www.cdc.gov/hepatitis/hcv/cfaq.htm, 2016.
[2] Centers for Disease Control and Prevention. Viral hepatitis — hepatitis b information. http://www.cdc.gov/hepatitis/hbv/bfaq.htm, 2016.
[3] Centers for Disease Control and Prevention. Guide to immunization required for school entry. http://eziz.org/assets/docs/IMM-231.pdf, 2016.
[4] K Burk. San francisco department of public health responds to hepatitis c, strategic directions for 2015 and beyond. http://nebula.wsimg.com/fae40aa85ea112e06f562a1083148e7e?AccessKeyId=C8BA516A29464966520B&disposition= &alloworigin=1, 2015.
[5] Centers for Disease Control and Prevention. Viral hepatitis and liver cancer. https://www.cdc.gov/nchhstp/newsroom/docs/factsheets/viral-hep-liver-cancer.pdf, 2016.
[6] Kathleen N Ly, Jian Xing, R Monina Klevens, Ruth B Jiles, John W Ward, and Scott D Holmberg. The increasing burden of mortality from viral hepatitis in the united states between 1999 and 2007. Annals of internal medicine, 156:271–278, February 2012.
[7] End Hep C SF. Hepatitis c in san francisco. https://cdn.shopify.com/s/files/1/1376/6245/files/SF_HCV_Prevalence_Estimate_Summary_revised_8.17.pdf?561498427740539732, 2017.
[8] Centers for Disease Control and Prevention. Viral hepatitis. http://www.cdc.gov/hepatitis/abc/index.htm, 2016.
[9] Centers for Disease Control and Prevention. Chronic hepatitis b and hepatitis c infections in california: Cases newly reported through 2011. https://www.cdph.ca.gov/programs/Documents/ChronicHepBandHepCinCalifornia,2011.final(Rev).pdf, 2013.
[10] Cancer Prevention Institute of California. 2014 report: The state of cancer in the greater bay area, 2014.
[11] Centers for Disease Control, Prevention, et al. Notice to readers: national hepatitis b initiative for asian americans/native hawaiian and other pacific islanders. Morb Mortal Wkly Rep, 58(18):503, 2009.
[12] World Health Organization. Hepatitis b. http://www.who.int/csr/disease/hepatitis/whocdscsrlyo20022/en/index1.html, 2017.
[13] California Cancer Registry. Age-adjusted invasive cancer incidence rates by county in california.
[14] National Cancer Institute. State cancer profiles.
[15] San Francisco Hep B Free. San franciso hep b free. https://www.sfhepbfree.org/, 2017.