Overview

What Is It?

The hepatitis viruses all cause acute inflammation of the liver, and some infections related to hepatitis B and C may become chronic.

You've probably heard warnings about hepatitis, a category of viral infections that can cause serious liver damage and even lead to death. Hepatitis literally means inflammation of the liver (hepa = liver; it is = inflammation).

If you're having trouble keeping up with the alphabet soup of the types of the hepatitis virus you're not alone. There are five main types: A, B, C, D and E. In the United States, the most common forms of hepatitis are hepatitis A, hepatitis B and hepatitis C.

All of the hepatitis viruses can cause acute hepatitis, which, in adults, usually resolves on its own over time. In contrast, the hepatitis B and C viruses may not go away and may evolve to a chronic ongoing infection. Although acute hepatitis, regardless of the type of virus, is often not associated with any symptoms, if there are symptoms, the main ones are:

• jaundice (yellowing of the skin and eyes)
• fatigue or malaise
• abdominal pain
• appetite loss
• nausea
• diarrhea
• vomiting

The good news is that there are vaccines against hepatitis A and hepatitis B. The vaccines are safe and effective. People who develop antibody in response to vaccination are protected from both acute and chronic hepatitis if they experience an exposure to these viruses after vaccination. The U.S. Centers for Disease Control and Prevention (CDC) recommends that all children be vaccinated against hepatitis B at birth. The Advisory Committee on Immunization Practices recommends that "at-risk" infants, or infants of parents requesting vaccination, undergo hepatitis A vaccination at age 1.

Hepatitis A

Hepatitis A is an acute liver disease caused by the hepatitis A virus that lasts for a few weeks to a few months. It does not lead to chronic liver infection. According to the CDC, there were about 21,000 new hepatitis A infections in 2009. In 2009, the incidence of hepatitis A was 1 per 100,000, the lowest number ever recorded.

Symptoms of hepatitis A usually do not appear until you have had the virus for a month and include fatigue, nausea and vomiting, abdominal pain or discomfort, appetite loss, low-grade fever, dark urine, muscle pain, itching and yellowing of the eyes and skin (jaundice). Not everyone with the infection develops symptoms. Symptoms usually clear up within two months but may last as long as six months.

You can contract hepatitis A via the following:

• drinking contaminated water
• eating raw shellfish from polluted water
• close contact with someone who is infected
• sexual intercourse with someone who has the virus
• eating food that was handled by someone who didn't wash his or her hands thoroughly after using the bathroom

You are at an increased risk of contracting hepatitis A if you:

• travel to regions with high rates of hepatitis A
• use illicit drugs (injected or non-injected)
• live with another person who has hepatitis A
• work in a setting where you might be exposed to the virus
• receive clotting factor concentrates for a medical condition

For most women, the biggest risk factors are sexual or household contact with an infected person or travel to countries where hepatitis A is common.

For hepatitis A, vaccination is recommended for the following people:

• children age one or who did not receive the vaccination at age one
• travelers to areas with increased rates of hepatitis A
• men who have sex with men
• injecting and non-injecting illicit drug users
• people with chronic liver disease
• health care workers, such as medical, dental, surgical and other

Hepatitis B

Hepatitis B is a liver disease caused by the hepatitis B virus that ranges from an acute mild illness lasting for a few weeks to a serious chronic illness that can eventually lead to liver disease or cancer. Many people with the infection have no symptoms; when symptoms occur, they may include fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, clay-colored bowel movements, joint pain and jaundice.

Hepatitis B rates have declined by 82 percent since 1990, when the vaccine was first given to children. About 15 percent to 25 percent of people who are infected with hepatitis B develop chronic infection. Approximately 800,000 to 1.4 million people are chronically infected with hepatitis B in the United States, and about 2,000 to 4,000 per year die from the disease.

One leading mode of transmission is unsafe sex. The virus is also spread by shared needles, from a mother to her newborn, sharing razors or toothbrushes with an infected person, direct contact with blood or open sores of an infected person or exposure to contaminated blood via needle sticks or other sharp instruments. Screening of blood donors has virtually eliminated transmission via blood transfusion.

All pregnant women in the United States should be screened for hepatitis B. If infected, the baby will need to receive specific hepatitis B immune globulin and be vaccinated at birth.

Vaccination against hepatitis B is also recommended for:

• all infants, starting with the first dose of hepatitis B vaccine at birth
• all children under age 19 who have not been vaccinated
• people whose sex partners have hepatitis B
• sexually active people who are not in long-term mutually monogamous relationships
• anyone diagnosed with a sexually transmitted disease
• men who have sex with men
• injection drug users
• household contacts of chronically infected persons
• health care and public safety workers at risk for contact with contaminated blood or bodily fluids
• people with end-stage renal disease
• residents and staff of facilities for developmentally disabled persons
• people with chronic liver disease
• travelers to areas with moderate or high rates of hepatitis B infection
• people with HIV infection
• anyone who wishes to be protected against hepatitis B

Several drugs are approved for treatment of chronic hepatitis B. These include interferon alfa-2b, peginterferon alfa-2a, lamivudine, telbivudine, adefovir, tenofovir and entecavir. An experienced health care professional can help determine the best treatment for an infection.

Hepatitis C

Hepatitis C is a liver disease caused by the hepatitis C virus. Acute infection rarely causes symptoms. Most often, however, hepatitis C becomes a chronic condition that primary care providers can detect by slight abnormalities of liver tests. An estimated 3.2 million people are chronically infected with hepatitis C in the United States, and about 75 percent to 85 percent of people who contract hepatitis C develop chronic infection.

In some cases, chronic hepatitis C can lead to cirrhosis and its complications, including need for liver transplantation, liver cancer and even death from liver disease. Over 20 percent of those with chronic infection will develop cirrhosis over a 20- to 30-year period, and up to 5 percent of people with cirrhosis will develop liver cancer or will die from complications of liver disease. Currently, hepatitis C causes up to 15,000 deaths a year, and that number is expected to increase throughout this decade.

Most people with hepatitis C don't realize they are infected, and they don't become aware of their infections until liver damage shows up decades later. When symptoms do occur, they include fatigue, fever, nausea or poor appetite, muscle and joint pains and tenderness in the area of the liver. Because most patients have few symptoms, chronic hepatitis C is sometimes described as a "silent epidemic."

You should be tested for hepatitis C if you fit into one of the following categories:

• You are a current or former IV drug user.
• You were treated for a blood clotting condition before 1987.
• You received a blood transfusion or organ transplant before July 1992.
• You are on long-term hemodialysis treatment.
• You have abnormal liver tests or liver disease.
• You work in health care or public safety and were exposed to blood through a needle stick or other sharp object injury.
• You are HIV positive.

Chronic hepatitis C can be cured by antiviral therapy, and treatment options are rapidly evolving. See the Treatment section for more information.

Hepatitis D

Hepatitis D only occurs in people with hepatitis B, and it can make an existing hepatitis B infection worse. Luckily, hepatitis D is uncommon, affecting less than 5 percent of people with hepatitis B. Because hepatitis D only occurs in people with hepatitis B, you can protect yourself against both by getting the hepatitis B vaccine.

Hepatitis D is treated by first treating the underlying hepatitis B infection. In some cases, additional therapy with long-term peginterferon may be warranted. See the Treatment section for more details.

Hepatitis E

Hepatitis E virus is similar to the hepatitis A virus in mode of transmission, and it may occur as part of large water- or food-borne epidemics. Hepatitis E spreads through contact with food or water contaminated by feces from an infected person. At risk are international travelers, people living in areas where hepatitis E outbreaks are common and people who have sex with or live with an infected person. To limit risk of hepatitis E exposure, avoid tap water when traveling internationally and practice good hygiene and sanitation.

Like hepatitis A, hepatitis E generally only occurs as an acute hepatitis. Although increasingly recognized, acute hepatitis E is relatively rarely diagnosed in the United States. Acute infection usually clears up after several weeks to a few months. In immunosuppressed patients, hepatitis E may evolve into chronic infection.

There is no specific therapy for acute hepatitis E. In the rare cases of chronic hepatitis E associated with immunosuppression, reduction in immunosuppression and ribavirin may effectively treat the infection.

Diagnosis

The specific virus causing hepatitis is defined by serologic or RNA/DNA testing of blood serum samples. In both acute and chronic hepatitis, the degree of ongoing liver injury is defined by changes in blood tests that measure liver enzymes. The level of impairment is measured by blood levels of bilirubin, albumin and INR.

In acute hepatitis, liver biopsy may be used in rare situations to assess the severity of liver damage and likelihood of recovery. In chronic hepatitis (B or C), liver biopsy is used to define the grade of inflammation (0 to 4) and stage of fibrosis (0 to 4). Imaging with ultrasound, computed tomography (CT) or magnetic resonance imaging (MRI) is commonly used in people with chronic hepatitis B or C to diagnose or monitor liver cancer, advanced fibrosis or cirrhosis.

Hepatitis A

Acute hepatitis A is diagnosed by a positive blood test for IgM antibody against hepatitis A virus (IgM-HAV-Ab). If you have been previously exposed to the hepatitis A virus but have cleared the infection and now have long-lasting immunity, then the blood test will be positive for IgG antibody against hepatitis A virus (IgG-HAV-Ab).

Hepatitis B

There are a number of tests used to diagnose hepatitis B and to determine the severity of an infection, including the following:

• Hepatitis B surface antigen (HBsAg)—a positive test implies current active infection with hepatitis B virus.
• Hepatitis B core antibody (HBcAb)—indicates prior exposure to the hepatitis B virus.
• Hepatitis B surface antibody (HBsAb)—indicates prior exposure to hepatitis B surface antigen, either as natural infection (in which case HBcAb is also positive) or as HBV vaccination (in which case HBcAb is negative).
• Hepatitis B e antigen (HBeAg)—indicates active HBV replication.
• Hepatitis B e antibody (HBeAb)—interpretation of HBeAb is complicated; if you are taking antiviral therapy, conversion from positive HBeAg/negative HBeAb to negative HBeAg/positive HBeAb is classified as "seroconversion" and identifies people on chronic antiviral therapy who have the lowest rate of relapse when antiviral therapy is discontinued.
• HBV DNA—this test measures the whole intact virus and is the primary test to define the magnitude of viral replication and the response to antiviral treatment.

Hepatitis C

There are three blood tests used to test for hepatitis C. These tests include:

• HCV Ab—this is an antibody test and indicates prior exposure to the hepatitis C virus.
• HCV RNA—this tests for the intact virus and confirms ongoing infection with HCV and measures response to treatment.
• HCV genotype—HCV exists as a family of viruses, called genotypes, which are labeled 1 through 6. The main role of HCV genotype is to define the type and duration of therapy.

Treatment

Hepatitis A

Hepatitis A differs from hepatitis B and hepatitis C in that it doesn't usually cause chronic infection or chronic liver disease. Almost all cases resolve after a month or two. Treatment for the infection involves easing the symptoms and may include rest and time away from work or school to cope with the fatigue; eating small meals and soft, easily digestible foods to deal with the nausea; and eliminating alcohol and any medications that may tax your liver while it is healing.

Because symptoms of hepatitis A can be sudden and severe, hospitalization may be necessary for patients who become dehydrated from vomiting or who have severe hepatitis. People who have had contact with someone with acute hepatitis A may require treatment with immune serum globulin and/or hepatitis A vaccine.

Hepatitis B

Generally, there is no specific treatment for acute hepatitis B. In cases of severe acute hepatitis B, your health care provider may recommend nucleoside/nucleotide treatment to try to prevent progression to liver failure.

Anyone who has been in contact with someone who has acute hepatitis B may require treatment with hepatitis B immune globulin and/or hepatitis B vaccine. If you suspect you've just been exposed and potentially infected with the hepatitis B virus, call your doctor right away. An injection of hepatitis B immune globulin and vaccine within a short time after exposure can help protect you against the virus.

If your doctor determines that your hepatitis B infection is chronic, he or she may prescribe medications to help your body fight the virus and prevent liver damage. Not everyone with chronic infection needs medication.

If your doctor determines you need medication, you will be prescribed a drug or combination of drugs to help slow or stop the virus from damaging your liver. Your doctor will decide which drug or drugs are likely to work for you and will then monitor your symptoms while you are taking medication to make sure the treatment is working.

The following medications are used to treat chronic hepatitis B:

Drugs given by injection:

• interferon alfa-2b (Intron A)
• peginterferon alfa-2a (Pegasys)

Drugs taken orally:

• lamivudine (Epivir-HBV, Zeffrix, Heptodin)
• adefovir (Hepsera)
• entecavir (Baraclude)
• telbivudine (Tyzeka, Sebivo)

If your liver is severely damaged as a result of a chronic hepatitis B infection, you may need a liver transplant, where a surgeon removes your damaged liver and replaces it with a healthy one.

As a preventive measure, you should avoid alcohol and cigarettes. You should also get vaccinated against hepatitis A. In addition, talk to your doctor before taking any prescription or over-the-counter medication, including herbal remedies.

Hepatitis C

Detection and diagnosis of acute hepatitis C is rare. However, there is effective treatment for acute hepatitis C. The treatment for acute hepatitis C is administration of peginterferon or peginterferon/ribavirin for 24 weeks. Treatment is more than 90 percent effective if administered within 12 weeks of onset of acute hepatitis. Your doctor may also recommend fluids and good nutrition.

Most people who receive treatment for hepatitis C have chronic hepatitis, though not everyone with chronic hepatitis C requires treatment with medications. Current first-line antiviral therapies approved by the Food and Drug Administration (FDA) are peginterferon/ribavirin with either telaprevir or boceprevir for HCV genotype 1 and peginterferon/ribavirin for HCV genotypes 2 or 3. Treatment for chronic hepatitis C is rapidly evolving, and many new therapies are on the horizon. New antiviral drugs, such as sofosbuvir, simeprevir, daclatasvir and faldaprevir, are under review by the FDA. If approved, they may make treatment shorter or less complicated or have fewer side effects.

In addition to drug therapy, you should get plenty of rest and avoid any substances that are toxic to the liver, such as alcohol and cigarettes. If you have chronic hepatitis C, you should be vaccinated against hepatitis A and B. Discuss any over-the-counter or prescription remedies with your health care professional before taking them.

Common side effects from peginterferon/ribavirin include flu-like symptoms, such as muscle aches, mild rash, fever, chills and headaches. Often these can be managed by taking interferon at night or by lowering the dosage. Acetaminophen or similar agents can also reduce flu-like symptoms if taken before treatment. Other side effects of interferon include depression, hair loss and irritability. Boceprevir and telaprevir cause anemia and telaprevir causes rash, which in some cases can be severe.

Prevention

Because chronic viral hepatitis is often a "silent infection," it is difficult to know who is infected. Avoiding unsafe sex and exposure to blood are good preventive measures. Prior to availability of testing in 1992, transfusion of blood or blood products was a common mode of transmission of both hepatitis B and C. Today, with sensitive and specific testing of blood donors, the risk is dramatically reduced to nearly zero. Using condoms for intercourse or oral sex on a man also protects you against other sexually transmitted diseases.

However, the best protection comes from vaccines. Safe and effective vaccines are available for hepatitis A and B, and research on a vaccine for hepatitis C is under way.

Hepatitis A

According to the CDC, the best way to prevent hepatitis A is to be vaccinated against the infection. The hepatitis A vaccine is recommended for all children at age one year, for travelers to certain countries where hepatitis A is more prevalent and for people at high risk for the infection, including men who have sex with men, IV drug users, people with chronic liver disease, such as hepatitis B or C, people treated with clotting factor concentrates and people who work with the hepatitis A virus.

The hepatitis A vaccine is given as two shots, six months apart. A combination hepatitis A and B vaccine is also currently available for adults 18 years of age and older, given as three shots over six months or as three shots over one month and a booster shot at 12 months.

The hepatitis A vaccine is safe and effective, with protection beginning two to four weeks after the first injection.

In addition, because hepatitis A spreads via fecal matter, frequent hand washing with soap and warm water, particularly after using the bathroom, changing a diaper or preparing food, can help prevent hepatitis A.

Hepatitis B

The primary way people become infected with hepatitis B is through contact with blood or body fluids of an infected person. For example, you can become infected by having sex or sharing needles with an infected person. In many developing countries, the most common means of infection is mothers passing the virus to their infants during childbirth.

Hepatitis B is not spread through food, water or casual contact. Although the virus is found in saliva, kissing is not considered a high risk. The greatest risk of infection from sexual contact is vaginal and anal sex. Having multiple partners increases that risk. Oral sex also can transmit the virus but not as efficiently as vaginal or anal sex. To help prevent infection, make sure you know the hepatitis B (and other STD) status of all your sexual partners and use a latex condom every time you have sex.

As with hepatitis C, any procedure or activity that puts you in direct contact with another person's blood puts you at risk for hepatitis B. Many people were infected through blood transfusions before hepatitis B was screened in blood donors. Today, however, infection from transfusion is very rare. It is possible to get hepatitis B from sharing razors, toothbrushes, pierced earrings and nail clippers, but the risk is low. Injection drug users get hepatitis B and C when sharing used syringes and needles because traces of a user's blood often remains inside the equipment. Tattooing and, possibly, body piercing can spread the virus if needles are reused without sterilization.

Because of the prevalence of hepatitis B, prevention through vaccination is recommended for all babies at birth and all children ages 19 and younger who have not been vaccinated. Adults who are at risk also should be vaccinated.

The hepatitis B vaccine prevents both infection and the complications related to the infection. It is given in a series of three to four injections over six months. The vaccine is completely safe and offers greater than 90 percent protection against hepatitis B. Since it was introduced in 1982, more than 100 million people have received the hepatitis B vaccine in the United States, and no serious side effects have been reported. The injections cause only mild soreness in the arm. Side effects other than fever and headache are rare.

A combination hepatitis A and B vaccine is available for adults 18 years of age and older, given as three shots over six months or three shots over one month and a booster at 12 months.

Hepatitis C

No vaccine is available to prevent hepatitis C. To avoid the disease, you must control risk factors. Currently, the most common ways of getting hepatitis C are injecting or snorting illegal drugs with shared equipment, tattooing or body piercing with unsterilized instruments and using an infected person's toothbrush or razor.

Hepatitis C is transmitted mainly through blood exposure—for example, intravenous drug use, sharing sharps or transfusion or transplantation of infected blood, tissues or organs. It may also spread via sexual activity, but the risk of transmission through sexual contact is believed to be low. This risk is higher for people with multiple sex partners, men who have sex with men or people who have a sexually transmitted disease, who engage in rough sex and who are HIV positive. More research is needed to better understand exactly how hepatitis C spreads through sexual contact.

Another suspected mode of transmission for hepatitis is tattooing. Be certain that disposable equipment and sterile techniques are used if you decide to get a tattoo.
Hepatitis C is not spread by casual contact, such as hugging or kissing, or by sharing eating utensils or coughing.

The risk of a hepatitis C-infected mother transmitting the virus to her infant is approximately 4 percent. Risk increases in mothers who are HIV-positive. There is no evidence that breast-feeding spreads hepatitis C.

Facts to Know

1. An estimated 3.2 million Americans have chronic hepatitis C infection, according to one major health survey. But, experts think that number could be higher than 5 million. Most people with hepatitis C do not know they are infected because they do not have symptoms. Hepatitis C causes up to 15,000 deaths annually from complications of cirrhosis of the liver or liver cancer and is the leading cause of liver transplants.
2. Although up to 85 percent of people infected with hepatitis C develop chronic liver disease, more than half will have no symptoms. Progression to cirrhosis is slow, and complications of liver disease may not be apparent until 30 years or more after infection.
3. Chronic hepatitis B and C are treatable by antiviral medications.
4. About 15 percent to 25 percent of people with chronic hepatitis B develop serious liver diseases such as cirrhosis and liver cancer. About 2,000 to 4,000 people die from hepatitis B-related liver disease per year.
5. Thirty percent of adults with acute hepatitis B infection never show symptoms. Most adults, up to 94 percent, will develop antibodies and clear the infection. The risk of chronic infection is greater in children who become infected—up to 50 percent. Those who don't clear the infection develop chronic infection and can infect others for the rest of their lives.
6. As many as 1.4 million Americans have chronic hepatitis B infection.
7. Hepatitis B is highly contagious. Experts estimate it is up to 100 times easier to become infected from a single exposure than from a single exposure to HIV.
8. Hepatitis B is not spread through food, water or casual contact. The greatest risk of infection is through sexual contact. Kissing is not considered a risk, although the virus is found in saliva.
9. Hepatitis A is most commonly transmitted through fecal-oral contact, either by person-to-person transmission from household contact with contaminated objects and materials or through contaminated food or water. For example, you can get hepatitis A by changing the diaper of a baby who is infected with the virus and not cleaning up properly (disinfecting changing surfaces and washing your hands) or by drinking contaminated water while traveling. Fruits, vegetables, shellfish and other foods that are eaten raw can transmit the virus if they were processed with contaminated water. Hepatitis A is less common in the United States than in developing countries such as some parts of Mexico, Africa, Southeast Asia, Haiti and the Dominican Republic.
10. Hepatitis A, which reproduces in the liver and is shed in the feces, causes an infection that produces complete immunity so that a person never becomes infected again or has symptoms. Also, a person is infectious for a short time, so transmission conditions have to be just right for an outbreak to occur.

Questions to Ask

Review the following Questions To Ask about hepatitis so you're prepared to discuss this important health issue with your health care professional.

1. If I test positive for hepatitis, should my partner also be tested?
2. How can I avoid passing hepatitis to my children? Can I breastfeed if I have hepatitis?
3. If I have hepatitis C, does it make sense to get vaccinated for hepatitis A or hepatitis B?
4. If I have chronic hepatitis C, do I need a liver specialist to oversee my care?
5. How much will treatment for chronic hepatitis C cost per year?
6. Do I need to refrain from sexual contact before I have completed the hepatitis B vaccine schedule?
7. How long will a vaccine protect me from hepatitis A and B?
8. Are the drugs used for treating hepatitis B and C safe, and what happens if I accidentally take too much?
9. What happens if I am infected with hepatitis but never get treated? Will it go away on its own?

Key Q&A

Organizations and Support

For information and support on coping with Hepatitis, please see the recommended organizations, books and Spanish-language resources listed below.

American Liver Foundation
Website: https://www.liverfoundation.org
Address: 75 Maiden Lane, Suite 603
New York, NY 10038
Hotline: 1-800-GO-LIVER (1-800-465-4837)
Phone: 212-668-1000

American Sexual Health Association (ASHA)
Website: https://www.ashasexualhealth.org/
Address: P.O. Box 13827
Research Triangle Park, NC 27709
Hotline: 1-800-227-8922
Phone: 919-361-8400
Email: info@ashastd.org

CDC National Prevention Information Network
Website: https://www.cdcnpin.org
Address: P.O. Box 6003
Rockville, MD 20849
Hotline: 1-800-458-5231
Phone: 404-679-3860
Email: info@cdcnpin.org

Hepatitis B Foundation
Website: https://www.hepb.org
Address: 3805 Old Easton Road
Doylestown, PA 18902
Phone: 215-489-4900
Email: info@hepb.org

Hepatitis C Caring Ambassadors Program
Website: https://www.hepcchallenge.org
Address: 604 East 16th Street, Suite 201
Vancouver, WA 98663
Phone: 360-816-4186

Hep-C ALERT
Website: https://www.hep-c-alert.org
Address: 660 NE 125 Street
North Miami, FL 33161
Hotline: 1-877-HELP4HEP (1-877-435-7443)
Phone: 305-893-7992
Email: web@hep-c-alert.org

National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention
Website: https://www.cdc.gov/nchhstp
Address: Centers for Disease Control and Prevention
1600 Clifton Road
Atlanta, GA 30333
Hotline: 1-800-CDC-INFO (1-800-232-4636)
Email: cdcinfo@cdc.gov

National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK)
Website: https://www.niddk.nih.gov
Address: Building 31, Room 9A06
31 Center Drive, MSC 2560
Bethesda, MD 20892
Phone: 301-496-3583

The Association of Asian Pacific Community Health Organizations (AAPCHO)
Web Site: https://www.aapcho.org/
Address: 300 Frank H Ogawa Plaza, Suite 620
Oakland, CA 94612
Phone: 510-272-9536
Email: nagrewe@aapcho.og

Books

Living with Hepatitis C: A Survivor's Guide
by Gregory T. Everson, MD, FACP

Living with Hepatitis B: A Survivor's Guide
by Gregory T. Everson, MD, and Hedy Weinberg

Curing Hepatitis C: Current and Future Options for Treatment
by Gregory T. Everson, MD, FACP

Spanish-language resources

CDC - Department of Health and Human Services
Website: https://www.cdc.gov/spanish/enfermedades/hepatitis/
Address: Centros para el Control y la Prevención de Enfermedades
1600 Clifton Road
Atlanta, GA 30333
Hotline: 1-800-311-3435
Phone: 404-639-3311

The National Digestive Diseases Information Clearinghouse
Website: https://www.niddk.nih.gov/health-information/informacion-de-la-salud/enfermedades-higado/hepatitis-viral/que-es
Address: 2 Information Way
Bethesda, MD 20892
Hotline: 1–800–891–5389
Email: nddic@info.niddk.nih.gov