The Hepatitis Viruses
Hepatitis is an inflammation of the liver caused by toxic substances, or by viruses (most cases). Hepatitis, or liver damage, is most often due to an infection (virus) or of toxic origin (alcohol and drugs). Viral hepatitis is classified from A to G according to the family of the virus involved. These viral infections can affect people who are also at risk for HIV and other STIs, depending on the situation. Here is the primer on the main hepatitis, how they work, how to prevent them and how to screen them.
Cause
As soon as the viruses reach the liver, they enter its cells, the hepatocytes, and multiply there. The immune system which provides the body’s defenses then destroys the infected cells, which causes inflammation of the liver. Symptoms characteristic of acute inflammation of the liver are possibly observed during contamination by these viruses and can last several weeks: yellowing of the skin and eyes (jaundice or jaundice), dark urine, discolored stools, extreme fatigue, nausea, vomiting and abdominal pain. It is impossible to distinguish the different forms of hepatitis based on the symptoms of the acute phase of the disease. Unlike the hepatitis A and hepatitis E viruses, the hepatitis B and hepatitis C viruses can lead to a chronic carrier state, meaning that the subject does not shed the virus and can develop many years later the serious complications of chronic hepatitis: cirrhosis and liver cancer.
While the hepatitis A and B viruses were identified in the 1960s and 1970s, the hepatitis C and E viruses, previously referred to as “non-A-non-B” hepatitis, were identified more recently, in 1989 -1990.
Virus | Transmission modes | Symptoms | Protective measures |
Hepatitis A | – Transmission, most of the time, by exposure to contaminated water or to foods prepared with contaminated water; | – Jaundice (yellowing of the skin and eyes) – Discomfort – Loss of appetite – Stomach ache – Dark urine – Tired – Most people infected with hepatitis A will get well naturally | – Hepatitis A vaccine – Wash hands properly before and after preparing and eating food |
Hepatitis B | – Faecal-oral transmission (i.e. when contaminated stools get into a person’s mouth from improper hand washing or when stool containing hepatitis A contaminates water which is then consumed) | – Jaundice – Discomfort – Loss of appetite – Stomach ache – Dark urine – Tired – Absence of symptoms possible (at least 30% of severe cases have no symptoms) | – Hepatitis B vaccine – Safe sex – Avoid sharing items that may be contaminated with blood (toothbrush, razor, nail clippers, needle, drug snorting equipment) |
Hepatitis C | – Exposure to contaminated blood or blood products – Transmission from mother to child – Sexual relations (in rare cases) – Sharing personal items with an infected person (toothbrush, razors, nail clippers, needles, drug snorting equipment) | – The majority of cases have no symptoms – Possibility of jaundice – Discomfort – Loss of appetite – Stomach ache – Dark urine – Tired | – Avoid sharing items that may be contaminated with blood (toothbrushes, razors, nail clippers, needles, drug snorting equipment) |
Hepatitis D | – Usually only appears in people already infected with hepatitis B – Exposure to contaminated blood and, in rare cases, transmission through sexual intercourse – Sharing of contaminated personal items | – Jaundice – Discomfort – Loss of appetite – Pain in the area stomach – Dark urine – Tired – Absence of symptoms possible | – Hepatitis B vaccine – Safe sex – Avoid sharing items that may be contaminated with blood (toothbrush, razor, nail clippers, needles, drug snorting equipment) |
Hepatitis E | – Widespread in developing countries – Faecal-oral transmission (i.e. when contaminated stools get into a person’s mouth from improper hand washing or when stool containing hepatitis A contaminates water which is then consumed) – Transmission mostly through exposure to contaminated water or food prepared with contaminated water – Hepatitis E can be passed from mother to child, but it is more common in adults | – Jaundice – Discomfort – Loss of appetite – Stomach ache – Dark urine – Tired – 90% of children infected with hepatitis E have no symptoms | – Cuci tangan dengan benar sebelum dan sesudah menyiapkan dan makan makanan – Kewaspadaan ganda di negara berkembang |
Hepatitis G | – Affected individuals are often coinfected with other viruses, such as hepatitis C, hepatitis B and human immunodeficiency virus (HIV) – Exposure to infected blood or blood products – Possible transmission by sharing personal items contaminated with the virus – Possible transmission from mother to child at birth – Possible transmission during sex | No symptoms | – Hepatitis B vaccine – Safe sex – Avoid sharing items that may be contaminated with blood (toothbrush, razor, nail clippers, needles, drug snorting equipment) |
A pregnant woman infected with hepatitis B or hepatitis C can transmit the virus to her baby.
Viruses
Virus | Genre / form | Transmission | Genome | Chronicity | Vaccine |
VHA | Hepatovirus | Oral | ARN-sb | – | + |
VHB | Hepadnavirus | Blood | ADN-dbp | + | + |
VHC | Flavivirus | Blood | ARN-sb | +++ | |
VHD | Viroid | Blood | ARN-sb | + | |
VHE | HEV | Oral | ARN-sb | – |
Screening tests for Hepatitis viruses
When prescribed by a doctor, a blood sample may be collected in a hospital or other medical setting and sent to a laboratory for analysis. A simple blood test can detect hepatitis for:
- A virus (HAV) involves testing the blood for antibodies to the A virus (HAV). tests measures :
- A immunoglobulin M (IgM anti-HAV) antibody test: When a person is first infected with hepatitis A, the body produces IgM anti-HAV antibodies. These antibodies are usually detectable from two weeks after symptoms begin to around six months later.
- A immunoglobulin G (IgG anti-HAV) antibody test: The IgG anti-HAV antibody test detects IgG antibodies that develop later in the course of the disease. IgG antibodies are detectable in the body for life, providing protection against a future A virus infection. The IgG anti-HAV test is used to detect past HAV infections and may occasionally be used to determine if an individual has developed immunity from a previous infection or vaccination.
- A antibody test: The total HAV antibody test detects both IgM and IgG antibodies and thus is used to identify both current and past infections.
- B virus (HBV) antigens are proteins that appear in different areas of the virus.
- C virus (HCV) detects antibodies to HCV in the blood, but the results are not clear cut and should be interpreted carefully.
- D virus (HDV) causes the most aggressive form of viral hepatitis, with rapid progression to cirrhosis and hepatic decompensation in comparison with its better-known counterparts, B virus (HBV) and C virus (HCV). The D in HDV stands for delta, but it can be thought of as defective or destructive, given its dependence on HBV coinfection for its pathogenesis and potent clinical impact.
- E virus (HEV). The virus has at least 4 different types: genotypes 1, 2, 3 and 4. Genotypes 1 and 2 have been found only in humans. E infection is usually based on the detection of specific anti-HEV immunoglobulin M (IgM) antibodies to the virus in a person’s blood; this is usually adequate in areas where the disease is common. Rapid tests are available for field use.
- G virus (HGV). Currently, no serologic test is available. PCR tests for HGV are not widely available.
Information: Cleverly Smart is not a substitute for a doctor. Always consult a doctor to treat your health condition.
Sources: PinterPandai, HGV virus (NCBI: National Center for Biotechnology Information), World Health Organization (WHO), Medicinet, Healthline, Centers for Disease Control and Prevention (CDC), HBV (NCBI: National Center for Biotechnology Information), HCV (NCBI: National Center for Biotechnology Information)
Photo credit: Wellcome Collection
Licence: Public Domain Mark
Photo explanations: a diseased liver with abcesses: two figures showing symptoms of abscessus hepatis e periphlebitide. Chromolithograph by W. Gummelt, ca. 1897.
