Hepatitis A
Hepatitis A is always self limiting. Even without any treatment, the infection will always resolve and the virus will be cleared. In otherwise healthy individuals it hardly ever threatens life and will not result in any serious long term complications or residual effect. There is no carrier state for Hepatitis A. Once the individual recovers from the infection, he can no longer infect another individual and should be immune to a subsequent infection.
Hepatitis B and C
Hepatitis B and C infections are very different from Hepatitis A. A person who gets infected can either clear the virus or become permanently infected. This latter group of individuals becomes “carriers” of the virus. These asymptomatic carriers can then potentially infect others. In Hepatitis B, the risk of becoming a carrier is dependant on the age at which the infection occurs. The younger the individual at the time of infection, the higher the risk of becoming a carrier. If infected at birth, the risk of becoming a carrier is almost 100%. If infected as an adult, only 10-20% will become carriers. For Hepatitis C, almost all infected individuals will become carriers.
Carriers of Hepatitis B and C are at risk of developing complications of the disease. In the initial stages, they are usually completely asymptomatic. Only when severe liver damage has already occurred will they feel unwell. Progression is very slow and complications with symptoms become apparent only after many years to even decades after the initial infection. These complications include liver hardening (cirrhosis), liver failure and liver cancer. It is estimated that a Hepatitis B carrier is at 200-400 times the risk of developing liver cancer compared to a non carrier.
However these outcomes are not inevitable and it is only with further tests that we can stratify the risks for any individual carrier.
Diagnosis of Hepatitis
Blood test will be able to diagnose Hepatitis A, B, C infections and also identify carrier states for Hepatitis B and C. Early detection is important as it allows counseling, life style modifications and close follow up to detect complications in their earliest stages. It also alerts other close contacts and family members to undergo screening and, if needed, to get vaccinated against catching the infection.
Protection and Precautions
Vaccination is available for Hepatitis A and B. Protection is however never absolute. Despite being successfully “immunized”, infection can still occur if an exceptionally large load of virus is acquired. There is no vaccination for Hepatitis C.
For Hepatitis A, 2 vaccinations are required, spaced 6 months apart. Some degree of protection is already present 2 weeks after receiving the first injection but the full course will still require a second injection to be given 6 months later. Almost all individuals will develop protection and this is life long after the second injection. No further boosters are required. Individuals seeking vaccination before they travel to a high risk area should be vaccinated at least 2 weeks prior to departure. The second injection may be taken upon return at the scheduled time. Since it is acquired through eating and drinking contaminated food or water, the usual precautionary measures for all travelers with regard to food and water consumption will apply.
Hepatitis B immunization requires 3 injections to be administered over a period of about 6 months. It can be given at the same time as Hepatitis A vaccination. Not all individuals successfully develop immunity after vaccination. It is therefore advisable that a blood test is performed about a month after the 3rd injection to confirm successful immunization. Generally, for individuals with no high risk profile, no booster is needed once immunity is confirmed.
Conversely, for individuals who regularly come into contact with Hepatitis B carriers, regular 3-5 yearly immunity level checks are advisable. It is however still controversial if booster doses need to be given. As the transmission methods are similar, precautionary measures applicable to HIV infection would apply in casual sexual relationships. This is particularly so in high risk scenarios e.g. sexual contact with a commercial sex worker. In a monogamous spousal relationship, no special precautions are recommended as long as the partner is successfully immunized.
Treatment
Hepatitis A infection is usually self-limiting and in most cases, requires no medical intervention.
In contrast, Hepatitis B and C are serious diseases and there is ongoing research for drug therapy. Several drugs are now available but none are perfect. Tests need to be performed to determine if an individual will require or benefit from treatment. A specialist needs to be consulted for this decision to be made. Treatment is expensive, often requires injections, usually takes several months to a year to complete and is often associated with many side effects.
Dr Cheong Wei Kuen
MBBS (Singapore), MRCP (UK), M Med (Int Med), FAMS (Gastroenterology)
Consultant Physician & Gastroenterologist
Mount Elizabeth Medical Centre
WK Cheong Gastrointestinal & Liver Specialists Pte Ltd
Wednesday, August 20, 2008
The ABCs of Hepatitis
Introduction
Hepatitis refers to an inflammation of the liver. There are many causes of which viruses are but one category. Hepatitis A, B and C are infections of the liver by 3 different viruses.
All 3 forms of hepatitis are infectious.
Hepatitis A is acquired through consumption of fecally contaminated water or food, particularly shellfish. It can also be transmitted through oral-anal sex with a recently infected individual. The likelihood of an individual having had an infection by the Hepatitis A virus increases with age. In Singapore, by the age of 50 years, about 90% would have been exposed to the virus.
Hepatitis B and C, on the other hand, are acquired as a result of sexual intercourse with another infected person or contact with the blood of an infected person. Hepatitis B is more infectious than Hepatitis C. Sexual promiscuity and having multiple sexual partners are known high risk factors in the acquisition of both infections. Blood contact most commonly occurs during acupuncture, tattooing or piercings performed contaminated needles. Sharing of needles by drug addicts or those experimenting with “mainlining lifestyle drugs” is another mode of infection. In less developed medical services, contaminated blood products and even improperly sterilized surgical/dental equipment may serve as sources of infection. Sharing of razors, toothpicks, toothbrushes, nail clippers, combs with an infected person can also potentially transmit the viruses.
About 4% of Singaporeans are infected with Hepatitis B. They are said to be Hepatitis B carriers. Carriage rates varies between countries, e.g. China 43%, Taiwan 20%, Philippines 17%, Australia 1%, Japan 3%. Singapore has a Hepatitis C carriage rate of about 0.4 % – 1.7%.
Another very important mode of Hepatitis B transmission is from an infected mother to her children at the time of birth. This mode of transmission can be largely prevented by timely treatment of the newborn at birth. Transmission while the baby is still in the womb has also been documented but this is probably rare. All pregnant mothers should therefore be screened for Hepatitis B so that the appropriate precautions may be taken at birth to protect the newborn.
Hepatitis C transmission during birth can also occur but is much less common than Hepatitis B.
Because of similarities in transmission methods Hepatitis B and C, a single individual can often be infected by more than one virus. Lastly, HIV is also transmitted in much the same scenarios (sexual intercourse, blood contamination and contact) and therefore should be screened if Hepatitis B or C is diagnosed.
Symptoms of Hepatitis
Nausea, loss of appetite, jaundice (yellowing of the eyes and skin), abdominal discomfort and the passage of tea coloured urine are the most common symptoms of Hepatitis A, B and C. Infection can however often occurs without any symptoms and infected individuals can feel and look perfectly normal. This explains why many individuals do not realize they have been previously infected until tests are performed, either during general health, blood donation or insurance related screenings or when pregnant. Each type of infection has a different incubation period. This means that symptoms may only be apparent only several weeks to even a few months after the point of contact with an infected individual.
Dr Cheong Wei Kuen
MBBS (Singapore), MRCP (UK), M Med (Int Med), FAMS (Gastroenterology)
Consultant Physician & Gastroenterologist
Mount Elizabeth Medical Centre
WK Cheong Gastrointestinal & Liver Specialists Pte Ltd
Hepatitis refers to an inflammation of the liver. There are many causes of which viruses are but one category. Hepatitis A, B and C are infections of the liver by 3 different viruses.
All 3 forms of hepatitis are infectious.
Hepatitis A is acquired through consumption of fecally contaminated water or food, particularly shellfish. It can also be transmitted through oral-anal sex with a recently infected individual. The likelihood of an individual having had an infection by the Hepatitis A virus increases with age. In Singapore, by the age of 50 years, about 90% would have been exposed to the virus.
Hepatitis B and C, on the other hand, are acquired as a result of sexual intercourse with another infected person or contact with the blood of an infected person. Hepatitis B is more infectious than Hepatitis C. Sexual promiscuity and having multiple sexual partners are known high risk factors in the acquisition of both infections. Blood contact most commonly occurs during acupuncture, tattooing or piercings performed contaminated needles. Sharing of needles by drug addicts or those experimenting with “mainlining lifestyle drugs” is another mode of infection. In less developed medical services, contaminated blood products and even improperly sterilized surgical/dental equipment may serve as sources of infection. Sharing of razors, toothpicks, toothbrushes, nail clippers, combs with an infected person can also potentially transmit the viruses.
About 4% of Singaporeans are infected with Hepatitis B. They are said to be Hepatitis B carriers. Carriage rates varies between countries, e.g. China 43%, Taiwan 20%, Philippines 17%, Australia 1%, Japan 3%. Singapore has a Hepatitis C carriage rate of about 0.4 % – 1.7%.
Another very important mode of Hepatitis B transmission is from an infected mother to her children at the time of birth. This mode of transmission can be largely prevented by timely treatment of the newborn at birth. Transmission while the baby is still in the womb has also been documented but this is probably rare. All pregnant mothers should therefore be screened for Hepatitis B so that the appropriate precautions may be taken at birth to protect the newborn.
Hepatitis C transmission during birth can also occur but is much less common than Hepatitis B.
Because of similarities in transmission methods Hepatitis B and C, a single individual can often be infected by more than one virus. Lastly, HIV is also transmitted in much the same scenarios (sexual intercourse, blood contamination and contact) and therefore should be screened if Hepatitis B or C is diagnosed.
Symptoms of Hepatitis
Nausea, loss of appetite, jaundice (yellowing of the eyes and skin), abdominal discomfort and the passage of tea coloured urine are the most common symptoms of Hepatitis A, B and C. Infection can however often occurs without any symptoms and infected individuals can feel and look perfectly normal. This explains why many individuals do not realize they have been previously infected until tests are performed, either during general health, blood donation or insurance related screenings or when pregnant. Each type of infection has a different incubation period. This means that symptoms may only be apparent only several weeks to even a few months after the point of contact with an infected individual.
Dr Cheong Wei Kuen
MBBS (Singapore), MRCP (UK), M Med (Int Med), FAMS (Gastroenterology)
Consultant Physician & Gastroenterologist
Mount Elizabeth Medical Centre
WK Cheong Gastrointestinal & Liver Specialists Pte Ltd
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