Hepatitis B is a viral infection of the liver characterized by loss of appetite, body malaise, fatigue, weakness, fever, joint pain, dark urine and faeces, abdominal pain, nausea and vomiting. External manifestations of the disease include yellowing of the skin and whites of the eyes, also known as jaundice. Within 6 months of infection, inflammation of the liver often occurs, accompanied by scarring and significant damage to other vital organs. Cirrhosis is most likely to develop in patients over the age of 40, while others have an increased risk of liver cancer, HIV and hepatitis C.
In regions where hepatitis B is endemic, the virus spreads very often through perinatal transmission, ie when a mother gives birth to the baby, in which case chronic infection occurs. Horizontal transmission, or that through exposure to infected blood, can also occur, especially among children aged 5 and younger. Other means of transmission are through contact with the body fluids of infected people, such as through the use of contaminated needles and syringes, as well as unprotected sexual activity with multiple partners. The virus is quite resilient, as it is able to survive outside the human body for up to a week, at which time it can still infect people if transmitted into the bloodstream of an unvaccinated person.
Acute hepatitis B has no treatment, so care is mainly administered to offer comfort to the patient, while chronic hepatitis B is treatable with the use of oral antiviral drugs, among others. At present, no less than 780,000 patients succumb to complications caused by chronic hepatitis B, such as liver cancer, HIV and cirrhosis of the liver. In the United States, no less than 1.4 million people are carriers of hepatitis B, which means they can, and often do, infect other people through sexual contact, sharing needles and syringes or other means.
The highest rates of hepatitis B cases have been reported in East Asia and sub-Saharan Africa, where at least 5% of the population in some countries is diagnosed as suffering from chronic infection. Similar data have also been reported in the Amazon region, as well as in many countries located in central and southern Europe. The Indian subcontinent and the Middle East have also reported that 2% of 5% of the adult populations of their countries are chronically infected. Meanwhile, no more than 1% are infected in the northern and eastern regions of the United States.
The World Health Organization (WHO) supports the use of oral drugs, such as entecavir and tenofovir, among patients who have been diagnosed with chronic hepatitis B infection. These two are recognized as the most effective in suppressing the virus and, to date, very few cases of drug resistance have been reported. Above all, they are among the easiest to administer, where an oral pill a day is often all it takes to keep the virus under control. Side effects are also very few and far between, which is often the problem in most drugs currently used for serious illnesses.