A Killer in Our Midst

Going through your list for your annual physical check-up, you'll probably come across such basic examinations as blood and urine tests, chest X-ray, and checks for blood pressure and cholesterol levels. Some may add to their list a few extra tests, like a Pap smear to check for cervical cancer or a mammogram for breast cancer detection.

Yet very few would ever request a screening for the Hepatitis B Virus (HBV) which is actually very important. Many people ignore it, never knowing they are putting their lives at risk. Doctors, however, are warning that the virus can be fatal, and are urging everyone to undergo an HBV test as soon as possible.

Why should you be worried?

Dr Teerha Piratvisuth, a well-known Thai hepatologist, says the Hepatitis B Virus can be more fatal than people think. It is highly contagious, about 100 times more infectious than HIV.

"The virus is tough, as it can survive on a surface at room temperature for at least a week. When infected and if left untreated, the virus will damage the liver, and progress into cirrhosis and eventually liver cancer," says Dr Teerha.

Worldwide, as many as two billion people are now infected with the Hepatitis B Virus, and almost 350 million have chronic infections. Up to 40% of people with chronic Hepatitis B develop advanced liver disease. The statistics also show that 500,000-1.2 million people die each year from serious liver disease brought on by the virus infection. It is also the 10th leading cause of death worldwide.

In Thailand, between 4-7% of the population are infected with the virus, and liver cancer has become the leading cause of cancer deaths among Thai males.

"It's extremely worrying that people don't pay much attention to HBV. Most remain unaware of just how fatal the virus can be. There maybe some who are aware of the disease and the screening test, but they are only the tip of the iceberg," says Dr Teerha.

How is it transmitted?

The Hepatitis B Virus is mostly found in the blood of infected people, but high levels can also be found in semen, vaginal fluid and saliva. It is rarely, if ever, detected in urine, sweat, tears and breast milk. The virus can be passed on from one person to another through different ways such as:

- At birth. If the mother is infected, it is very likely that her child will be infected at or soon after birth.

- Living in a household with an infected person. This is a common way that children become infected.

- High risk or unprotected sex, especially when there are multiple partners or male partners.

- Being exposed to contaminated blood or blood products such as through blood transfusions. It has now become common medical practice that every blood donor has HBV screening before the donation.

- Sharing needles and syringes (e.g. injection drug users).

- Re-using acupuncture needles or tattoo instruments which have not been sterilised properly.

"Given these tranmsmission routes, the high risk groups will include children aged 0-3 years old, those immune compromised individuals, such as patients who are treated with chemotherapy, or people having organ transplants as they are given immunosuppressive drugs. Others can include people whose family members already have HBV, persons whose work involves close contact with blood like doctors and nurses, as well as intravenous drug users," says Dr Teerha.

Signs and symptoms

Symptoms occur in about 70% of adults who have Hepatitis B. However, it may take several months after a person has been infected for symptoms to appear.

"HBV is a silent killer because patients normally have no symptoms at the first stage. Most people don't know when they are infected. Once they feel any abnormality regarding their bodies, the disease has already got worse, and in some cases, it's too late to cure," says the doctor.

The symptoms that can occur include yellowing of the skin or eyes (known as jaundice), tiredness or fatigue, loss of appetite or nausea, darkening of the urine, fever and aching joints.

Types of infection

Dr Teerha explains that the Hepatitis B Virus can result in acute and chronic infections. A person who has been infected for less than six months is considered to have acute Hepatitis B. Within this six month period, most people's immune system will fight off the virus with no need for treatment.

However, those with less developed immunity, such as children, are unable to fight the infection, and will develop a chronic infection. This is found in 90% of newborns, 30% of children under five years old, and 10% of adults who are infected.

The acute type is less harmful. About 1% of patients with acute infection will die from liver damage at this early stage.

If the virus persists in the body for longer than six months, the person is diagnosed with chronic infection. The majority of chronic infections are caused by mother-to-baby transmission.

Many people with chronic Hepatitis B, particularly those infected when they were very young, have large amounts of the virus in their blood without any damage to the liver. This is because their immune system has not yet recognised the virus.

However, after some years, the body's immune system may recognise the virus and begin to attack the infected cells. This causes the liver to become inflamed, and over a long period of time can cause liver damage.

Up to 40% of patients who are chronically infected will end up with serious liver diseases, including liver inflammation, cirrhosis, liver failure and cancer. In many cases these diseases result in death.