Hepatitis means inflammation of the liver caused by hepatitis virus. The pathogen involved in this is called hepatitis virus which includes Hepatitis A virus (HAV virus), Hepatitis B virus (HBV virus), Hepatitis C Virus (HCV virus), Hepatitis D virus (HDV virus) & Hepatitis E virus (HEV). There exists Hepatitis G virus and Hepatitis TT virus but it does not cause hepatitis. These agents cause the same similar symptoms, though they all have different route of transmission.
Hepatitis A virus It is RNA virus which belongs to Genus hepatovirus and Family picornavirus. It replicates in the liver and is excreted in the faeces of infected persons for about 2 weeks before the onset of clinical symptoms.
Mode of Transmission Contaminated food or water (Faecal- oral route).
Incubation period 4 weeks
Signs & symptoms Infected patient may have mild flu like symptoms of anorexia, Vomiting, fatigue, malaise, head ache and low grade fever. Later it could be followed by jaundice with dark urine and pale stools. Pain in joints and rash can go together with the jaundice. There may be enlargement of the liver.
Investigation Anti-hepatitis A immunoglobulin M remains for 3-6months after the primary infection and it shows acute infection.
Anti-hepatitis A immunoglobulin stays for many years.
Levels of liver enzymes Alanine aminotransferase and Aspartate aminotransferase are increased. Serum bilirubin level can be increased as well.
There is lecuopenia with a relative lymphocytosis. Prothrombin time is prolonged in severe cases and Erythrocyte sedimentation rate is increased.
Treatment Usually supportive. Your immune system will take care of the offender. You have to make sure you do not drink or eat fatty food.
Prophylaxis If you are travelling to high risk zones of hepatitis A then it is advisable to avoid eating in such conditions especially anything uncooked or raw.
Immunisation One could get vaccinated if he knows that he is travelling to a high risk country 4-6 weeks before travel. A single doses turns out to produce antibodies for one year. When a booster is given, immunity then can lasts for up to 10years.
Prognosis It has excellent with most patients having complete recovery. Death may occur due to fulminant hepatic necrosis. Some cases may occur with prolonged course with 7-20 weeks and is called ‘cholestatic viral hepatitis’. There might be hindrance with weakness following resolution of symptoms and biochemical parameters. This is known as post-hepatitis syndrome.
Hepatitis B Virus It is a DNA virus which belongs to hepadnovirus.
Mode of Transmission Unprotected sexual contact with infected, Sharing of contaminated needles & syringes, vertical transmission from mother to child especially during child birth. All bodily fluids saliva, semen, vaginal secretions and blood contains hepatitis B virus.
Incubation Period 1-6 months
Hepatitis B virus usually can occur in two phases. It can be acute phase when one gets infected and chronic phase when the virus persists in the body.
Signs & Symptoms Patient will feel generally unwell, abdominal pains, vomiting and fever. Later on patient will develop jaundice.
Symptoms usually disappear in few weeks and virus is cleared from the body within 3-6months. In some cases it develops into chronic hepatitis which stays for life long. When a patient is with chronic infection, it might be symptomless and the virus will remain in the body and the patient will be a carrier or a chronic inactive hepatitis B.
In some cases liver is inflamed all throughout and it is called chronic active hepatitis in which patient might experience symptoms or can be asymptomatic.
In later years after infection with hepatitis B virus patient may develop cirrhosis of the liver which is scarring of the liver and it results in deterioration of the function of the liver.
There is risk of developing hepatocellular carcinoma.
Investigation
Blood test shows presence of hepatitis B surface antigen.
Liver function tests which will show the elevation of the liver enzymes
Ultrasound scans of the liver. Biopsy of the liver should be done to check if there is any progressing cirrhosis of the liver.
Various other portions of the virus particles can be seen which shows various stages of infection.
Treatment
No treatment can be helpful but they can ease the symptoms.
In case of chronic hepatitis treatment is given to reduce the progression of liver damage.
Interferon: It is a substance which helps to fight against the immunity. It fights against infection by providing stronger immunity.
Anti-viral drugs: These drugs which help to fight against the infection.
Liver transplantation can be helpful as well.
Diet and Alcohol Normal balanced diet can be continued. It is advisable to avoid cirrhosis.
Prophylaxis Avoid risk factors such as shared needles, multiple male homosexual partners and prostitutes.
Standard precautions must be followed in hospitals to avoid accidental needle punctures and contact with infected body fluids.
Immunisation should be done to people at high risk.
Hepatitis D It is caused by Hepatitis D virus or Delta virus. It is a RNA virus which does not have the capability to replicate on its own but is usually active only in the presence of Hepatitis B virus.
Investigation Ig M anti-delta along with presence of Ig M anti-HBc appears at one week and disappears by 5-6 years when serum Ig G anti-delta is seen.
Hepatitis C
It is a single stranded RNA virus of the Flaviviridae family. It consists of six genotypes. Out of which, genotype one is the most common in U.K.
Mode of transmission Intravenous drug users and blood transfusion (In England from 1991 September blood has been screened for Hepatitis C virus)
Haemodialysis
Sexual contact with infected individual
Needle stick injuries
Perinatal transmission
Signs & symptoms Usually asymptomatic
People will experience malaise, anorexia and weakness with jaundice. Most patient present in later years with abnormal liver function test or with Chronic liver disease.
Extrahepatic manifestations include Arthritis, Glomerulonephritis associated with cryoglobulinaemia and porphyria cutanea tarda.
Investigation HCV RNA can be detected 1 or 2 weeks after infection
Anti-HCV is usually positive 6 weeks from infection
Treatment Patient should be educated about the disease.
Patient should not donate blood, tissue or organ.
Alcohol could accelerate the destruction of the liver; hence excess alcohol intake must be avoided.
Pegainterferon alfa-2a and ribavirin can be prescribed .
Hepatitis E It is a RNA virus which belongs to the family Calicivirus.
Mode of transmission Contaminated water is the main source of infection
Zoonotic spread with dogs, pigs and rodents carrying the virus.
Signs & symptoms Clinical features similar to Hepatitis A virus
It is self limiting.
Investigation
HEV RNA can be detected in the serum or stools by PCR
IgM anti HEV and IgG anti HEV
Treatment Usually supportive
Prevention Good hygiene and sanitation
Avoid tap water in high risk area
No vaccine is available
We will meet in the next blog with another interesting disease.
