CLINICAL MATTER

As someone who clears seafarers for deployment abroad, I find that one of the most common reasons patients are referred to me is for hepatitis B infection. Most of these patients don’t feel anything and appear otherwise healthy. They are unpleasantly shocked and surprised when the hepatitis B screening test comes back positive and they are told by their employment agency that they are not fit to work. As an existential threat not just to their prospects for employment but their very lives, hepatitis B is a major problem for Filipinos. Hepatitis comes in many forms. The term hepatitis simply means inflammation of the liver. Aside from viruses, there are many other causes. These include alcohol, prescription drugs, supplements, and in some cases the body attacks the liver itself (autoimmune hepatitis). When we talk about hepatitis B and other hepatitis with letters (hepatitis A, C, D, E, G), we are referring to a group of viruses that have the ability to cause injury to the liver. These viruses can range in presentation from no symptoms to life-threatening disease. Among the different viral hepatitis types, hepatitis B is by far the most prevalent chronic hepatitis in Filipinos. While hepatitis A has probably infected more Filipinos than hepatitis B, hepatitis A in most patients is a self-limited disease that can cause flu-like symptoms, diarrhea, and jaundice (a yellowing of the skin), but these symptoms go away on their own. Hepatitis C causes chronic disease just like hepatitis B but is not as common in our country. Hepatitis D is a virus typically found with hepatitis B that can make it worse. Hepatitis E is similar to hepatitis A. It can be particularly severe in pregnant women. Because it is not routinely tested or treated, not much is known about hepatitis G.
Nearly 17 percent of Filipinos are infected with hepatitis B, which can be acquired in three ways: vertical transmission from mother to child (a pregnant woman infected with hepatitis B passes it on to her child); bloodborne transmission from transfusion of infected blood or sharing of contaminated needles; and through sexual intercourse. The most common route of infection in the Philippines is through vertical transmission. Vertical transmission in infants who have immature immune systems results in a suboptimal immune response and so the virus is able to establish a chronic (long term) infection, the damage from which accumulates over time. This can take the form of liver cirrhosis (liver scarring), which predisposes to the development of liver cancer. This can be so severe that some patients come in to see us with advanced liver cancer in their 20s or 30s. Sexually transmitted hepatitis B is less common. It can be self-limited since the immune system in adults is already mature, unlike in vertical transmission where it typically becomes chronic. The best way to diagnose hepatitis B is through a blood test. There are many tests for hepatitis B. It can get confusing but the typical screening test is called a hepatitis B surface antigen or HBsAg. HBsAg is a protein that is produced on the surface of the virus. It can be detected by running the blood through a machine. The detection of HBsAg means that the virus is present. Some patients infected with the hepatitis B virus are able to clear it and recover, so HBsAg will be negative but their hepatitis B antibody will be positive. Since hepatitis B vaccination also makes a patient positive for hepatitis B antibody, there are two antibody types that can be used to distinguish vaccination from infection. A hepatitis B surface antibody (anti-HBs) will be positive in both natural infection and vaccination while a hepatitis B core antibody (anti-HBc) will only be positive in previous infection. There are other tests we use to further describe hepatitis B infection (HBeAg, anti-HBe, HBV viral load) but HBsAg and anti-HBs are the usual screening starting points. This is where many people who wish to work abroad are tripped up by the blood test. It can be incredibly disappointing and overwhelming to test positive for a disease you didn’t know you had. But all is not lost. Advances in medicine have resulted in hepatitis B being a very treatable disease. While a cure for someone with chronic hepatitis B is very difficult to achieve, the current medications are very good at shutting down viral replication and preventing further liver damage. There are drugs that can be used to control hepatitis B, including entecavir and tenofovir, but these need to be taken for life. Not everyone with chronic hepatitis B needs to start treatment right away, but once the decision to treat is made, it should not be stopped since there is a danger of the virus reactivating and causing catastrophic liver failure. Unlike hepatitis C, which is curable now, chronic hepatitis B for will require lifelong treatment to decrease the risk of cirrhosis and liver cancer. The good news for hepatitis B is that it is a vaccine-preventable disease. We can prevent transmission from a pregnant woman who is hepatitis B-positive to her newborn infant by giving the baby a combination of the vaccine plus hepatitis B immunoglobulin. Hepatitis B vaccination is a routine part of childhood immunization, and catch-up hepatitis B vaccination can be done for adults, who are not yet immune to hepatitis B. Making sure your babies are vaccinated against hepatitis B within 24 hours of birth will prevent the heartbreaking scenario of testing positive for hepatitis B during pre-employment screening decades later. Speaking of pre-employment screening, this is not supposed to be required in the Philippines, unless someone is a healthcare worker. Testing is required by some countries prior to overseas deployment so it frequently shows up on medical examinations for people who want to work abroad. The risk of transmitting hepatitis B to other people through day-to-day interactions is negligible and there is no reason to discriminate against those living with hepatitis B. Ongoing treatment of hepatitis B further decreases this risk and many overseas employers are willing to hire Filipinos with hepatitis B as long as they are on proper medication and show no signs of liver damage. On July 28, World Hepatitis Day will be commemorated by free screening and educational programs conducted by healthcare institutions nationwide, in coordination with the Hepatology Society of the Philippines, to increase awareness of this treatable and preventable disease. If you have more questions about hepatitis B and how you can minimize your risk, talk to your family doctor for guidance.