Type of infection

Hepatitis is a name for any infection that causes liver inflammation or damage.

Three main causes of liver infection are hepatitis A (HAV), hepatitis B (HBV) and hepatitis C (HCV) virus. These are all very different viruses with different treatment.

This section mainly deals with HBV (which is acquired sexually including through saliva) and HCV (acquired by blood contact through infected needles, and more rarely sexually). With HIV, these are considered coinfections rather than OIs.

Main symptoms

Some of the symptoms of acute (early) or active liver infection, like nausea, vomiting, fatigue, diarrhoea, jaundice (yellow eyes or skin), are similar for any viral infection to the liver. Not everyone will get symptoms or even know they are infected. Intolerance to fatty foods or alcohol, a swollen or tender liver or ‘liver spots’ on the skin are other symptoms of hepatitis.

HBV

Hepatitis B can be transmitted by sexual exposure including oral sex and sharing injecting drug equipment, and is more infectious than HIV.

Up to 90% of HIV-positive people have already been exposed to HBV, with the majority clearing the virus without treatment.

HIV seems to makes HBV a more serious illness. Complications of managing HIV/HBV coinfection are largely related to some common HIV treatment working against both viruses.

Diagnosis

Blood tests can screen for either previous exposure to viral hepatitis or active infection. The symptoms listed above should prompt a doctor to test for HBV. Viral load (PCR) tests for hepatitis are used similar to HIV viral load tests, and can confirm an infection when immunological tests are either negative or unclear.

• Previous exposure to HBV is shown by testing positive for HBV core antibodies (HBcAb+) or HBV surface antibodies (HBsAb+).
• 2-10% of people exposed to HBV become chronic carriers and remain infectious, shown by a testing positive for HBV surface antigen (HBsAg+).

If HBV is cleared, you are usually immune to reinfection.

Treatment

HIV and HBV coinfection needs care from a doctor with experience of both infections.

Several drugs used to treat HIV also are active against HBV. These include 3TC, tenofovir and FTC. HBV is also treated with adefovir, a drug developed for HIV, but now used just for HBV in people who do not have HIV.

These drugs have to be used very carefully.

• 3TC, tenofovir and FTC should only be used in HIV-positive people in a 3 drug ARV combination because of the risk of HIV resistance.
• Adefovir can be used as single treatment if ARV treatment is not needed.
• Resistance to HIV and HBV treatment are different and occur independently.
• There is a serious risk of HBV reactivation, and severe or fatal liver toxicity, if the drugs active against HBV are stopped in someone who has not cleared the infection.

Interferon was an early injected treatment for HBV. This now used less often because tablets are easier to tolerate.

HBV can be successfully treated in many people. Sometimes life-long treatment is needed. Long-term HBV coinfection is a specialist area of disease management.

If HBV is cleared, you are usually immune to reinfection.

Prophylaxis

Effective vaccinations are available for hepatitis A and hepatitis B. Response to vaccines are related to CD4 count, and some clinics use higher doses in HIV-positive patients in order to improve the response rate. There is no vaccination against hepatitis C.

Research

Research into new drugs to treat hepatitis B is ongoing. Some of these will be available in the next 5-10 years.

HCV

HCV can take 20-25 years in HIV-negative people to progress to liver damage (scarring and liver cancer). Coinfection with HIV seems to approximately double the speed of HCV progression (ie taking form 10-15 years). Continued high use of alcohol is a major risk factor for faster HCV progression. Chronic (long-term) HCV is also associated with mental difficulties and depression.

Up to 20% of HIV-positive people clear HCV in the first months after infection, without needing HCV treatment.

HCV treatment for longer than one year may be more effective for some people.

If HCV is cleared, you are not immune and can catch it again.

Diagnosis

Blood tests can screen for either previous exposure to viral hepatitis (many people clear the virus without knowing they were infected, and produced antibodies) or active infection. The symptoms listed above should prompt a doctor to test for HCV.

Viral load (PCR) tests for hepatitis are used similar to HIV viral load tests, and can confirm an infection when immunological tests are either negative or unclear.

If you are diagnosed with HCV, then you need to have an HCV genotype test to find out which type of HCV you have (genotype 1, 2, 3 or 4).

Treatment

HIV and hepatitis C coinfection needs care from a doctor with experience of both infections and is highly specialised.

Combination HCV treatment with interferon or PEG interferon plus ribavirin for 48-weeks is current standard of care, but people with HCV coinfection may need longer treatment. In 2011 two new drugs were approved in the US that act directly against HCV: bocepravir and telaprevir. Where these drugs are available they have the potential to reduce the duration of HCV treatment. Currently these new drugs still need to be used with PEG-inferferon and ribavirin.

Response rates to treatment vary by HCV genotype. The proportion of people who clear HCV ranges from 30% for HCV genotype 1 or 4 to 60-70% for genotype 2 or 3. Response rates after 12 weeks may be an early sign of the effectiveness of treatment.

A successful response is defined as undetectable HCV viral load, six months after stopping HCV treatment. Most people who get this response have been cured of HCV.

Treatment is mainly used after long-term infection with HCV, when a liver biopsy or other test have show liver damage has progressed. If HCV is diagnosed in acute infection (within 6 months of infection) then early treatment can result in higher response rates.

Even if HCV is not cleared, treatment may improve liver health and delay disease progression.

Prophylaxis

Effective vaccinations are available for hepatitis A and hepatitis B. There is no vaccination against hepatitis C.

Research

There is extensive research into new drugs that work in other ways and which have less side effects than interferon, including oral drugs. Some of these will be available in the next 5-10 years.

Other areas of research include:

• Risks from low levels of alcohol use
• Use of non-invasive test to monitor liver damage instead of needle biopsies
• Duration of treatment needed with different HCV genotypes
• Earlier access to experimental HCV drugs for people coinfected with HIV

Further reading

The 2011 i-Base/TAG pipeline report includes a chapter on antiretrovirals that includes a review of new drugs for hepatitis C including a review of boceprevir and telaprevir.