HBV like HIV presents an elevated risk of occupational exposure to healthcare workers. The silver lining is that HBV is preventable with the currently available safe and effective vaccine, said Dr SK Guha, Professor, Department of Tropical Medicine, Calcutta School of Tropical Medicine, who was speaking at the 6th National Conference of AIDS Society of India (ASICON 2013).
People who use drugs (PWUD) and share needles or syringes are particularly at a heightened risk of contracting infections such as Hepatitis C Virus (HCV), HBV and/or HIV. 6.4 million PWUDs are estimated to be exposed to HBV in 59 countries and 1.2 million PWUDs are estimated to have developed chronic HBV infection. In Indonesia, HIV prevalence among PWUDs is estimated to be 36%, HBV prevalence at 57.6%, and yet there are no national clinical guidelines for diagnosis, treatment and care for HBV-HIV co-infection.
Dr SK Guha said that there is a high probability of spontaneous clearance of HBV. For instance more than 90% of immune-competent adults are likely to clear the virus spontaneously. But risk of chronic HBV infection setting in is highly elevated in people living with HIV (PLHIV): 20-40%.
Dr Guha said that vertical and perinatal transmission of HBV is common in Asia and Africa. Children too are at a very high risk (of up to 90%) of not only failing to clear HBV spontaneously but also developing a chronic HBV infection. Prevalence of HIV and HBV co-infection varies in Asian and African nations between 10-25%.
HIV and HBV co-infection rates in India hover between 8.3 – 11.3%. However among PWUDs the co-infection rates are obviously much higher, said Dr Guha (up to 15.9%).
IMPACT OF HIV ON HBV:
Underlining how HIV co-infection impacts HBV in an individual, Dr Guha said that HIV co-infection increases the risk of developing chronic HBV infection and greater levels of HBV viraemia. HIV co-infection also accelerates fibrosis, progression to cirrhosis and other serious complications. No wonder there is higher liver-related and overall mortality rates reported among people co-infected with HBV and HIV, said Dr Guha.
IMPACT OF HBV ON HIV:
Dr Guha also highlighted how HBV co-infection impacts HIV infection in an individual. He said that there is evidence to suggest that chronic HBV co-infection was not directly associated with progression to AIDS or to virological or immunological response to antiretroviral therapy (ART). But HBV co-infection does seem to increase the likelihood of PLHIV developing toxicity to ART and immune reconstitution hepatitis. Also there is a pronounced CD4 decline in HBV and HIV co-infected people. Maharashtra AIDS control Society (MACS) data shows increased liver mortality in HIV-HBV co-infected men.
HOW TO TAKE CARE OF HBV-HIV CO-INFECTED PEOPLE
Dr Guha advised that quality counselling on HBV and HIV co-infection related issues must be part of effective health programmes. Avoiding or limiting alcohol intake is also important for HBV and HIV co-infected people. Counselling on taking appropriate precautions to prevent transmission of both HBV and HIV infections is also very important.
CERTAIN ART DRUGS WORK AGAINST HBV TOO
Certain ART drugs have activity against both the viruses HIV and HBV. These ART drugs with dual activity against HBV and HIV are; Lamivudine (3TC), Tenofovir (TDF), Emtricitabine (FTC), and Etravirine. Dr Guha cautioned that monotherapy with 3TC is associated high HBV resistance (20% resistance by first year and 90% resistance by fourth year of treatment).
Dr Guha advised that preferred treatment option may contain highly active ART with two medicines that are active against both: HIV and HBV (mentioned above).
Guidelines of the National AIDS Control Organization (NACO) issued in 2012 suggest that ART should be started irrespective of CD4 count in people confirmed to have HIV and HBV co-infection.
In infants born to HIV-HBV co-infected mothers, HBV vaccine should be administered within 12 hours of birth and mother should be on tenofovir-TDF/ emtricitabine-FTC (or lamivudine-3TC) based ART regimen to reduce virus in blood and breast milk.
Dr Guha strongly advocated for HBV immunization especially for those PLHIV who are at an elevated risk to contract HBV.
Bobby Ramakant, Citizen News Service - CNS
December 2013
