HUMAN DISEASES: HEPATITIS

· Hepatitis is a communicable viral disease characterized by infection and inflammation of the liver.
· It is caused by viruses, toxic substances (drugs) and circulatory disturbances.
· There are many well-known heterogenous hepatitis viruses that cause viral hepatitis.
· In addition to type A and B viral hepatitis, type C, D, E, and G have also been reported as communicable viral diseases.

· The types are distinguished serologically i.e. by the antibodies produced to combat the infections.

Hepatitis ‘A’ (Infectious Hepatitis)

· It is endemic in developing countries.

· It is usually not fatal but in rare cases, its fatal rate is 0.1%.

· It is benign.

Causative agent: Hepatitis ’A’ virus:

· It is a small unenveloped symmetrical RNA virus that measures approximately 27 nm.

· Due to its very small size, the virus can easily transfer through the normal water filtration system.

· The virus invades liver cells and is excreted in bile and faeces.

Source of infection: Infected people can transmit the virus 2 weeks before or 1 week after the appearance of Jaundice.

Mode of transmission: Through faecal-oral route (through the mouth and alimentary canal), direct person to person contact or indirect with the ingestion of contaminated water, food or milk. Sexual transmission is also well reported.

Environmental factor: Common in the rainy season but can occur throughout the year.

Host: Affecting mainly children, but all age -groups and both sexes are infected.

Immunity: Once a person has recovered from Hepatitis A, he or she is immune to re-infection with hepatitis A for life. This is because effective antibodies are developed against the hepatitis A virus.

Incubation period: 15-40 days

Signs and symptoms:
· Non-specific symptoms like headache, chills, fever, fatigue, generalized weakness.

· Anorexia (loss of appetite), nausea, vomiting.

· Hepatomegaly (enlargement of the liver) and abdominal pain.
· Jaundice (The colour of the skin, white of the eyes are changed into yellow.)
· Dark urine
· No chronic hepatitis and liver cancer

Diagnosis:
· Detection of viral particles in faeces
· Abnormal liver function tests
· It is usually made on finding anti- HAV IgM in the serum though it is theoretically possible to also find the virus in faecal samples very early in the disease.

· Anti- HAV IgG may be found within 1 to 2 weeks and this remains detectable for many years conferring long term immunity to the individual.

· Liver function tests including serum bilirubin, aspirate, aminotransferase and alanine aminotransferase are elevated.

Treatment
Symptomatic treatment:
· Bed rest, soft and palatable food
· Single-dose hepatitis ‘A’ vaccine is available which provides protection from the virus for at least 10 years.
· Hepatitis A virus is made of killed hepatitis A viruses and causes the body’s immune system to produce antibodies against the hepatitis A virus.

· In most vaccine recipients, antibodies start to develop immediately after the first dose but do not reach protective levels for 2-4weeks.

· A second dose of the vaccine is recommended at least six months after the first dose to provide prolonged protection.

Prevention and Control
· Prevention of faecal contamination of food and water
· By improving personal and community hygiene
· Control of susceptible population by vaccination
· Public awareness through health education
· Control of flies and screening of kitchens and latrines
· During the epidemic, boiled or chlorinated water should be taken.

Hepatitis ‘B’ (Serum hepatitis or Transfusion hepatitis)

· It is the most widespread and versatile viral hepatitis.

Causative agent: Hepatitis ‘B’ virus (HBV). It is a DNA virus. It is also called Dane particle.

Source of infection: Only infected person

Mode of transmission: Hepatitis ‘B’ virus is a blood-borne virus and is transmitted by infected blood inoculation, from mothers to their babies, by sexual route, tattoos (both amateur and professionally done.), saliva and parenteral contact (taken in a body in a manner other than through digestive tract), shared personal items (such as toothbrushes, razors and nail clippers) with an infected person.

Hosts: Those people who come in contact with blood and blood products in their daily work like:
· Doctors mainly surgeons
· Laboratory technicians and workers
· Persons who need repeated blood transfusion.
· Intravenous drug abusers
· Prostitutes and homosexuals
· Infants of infected mothers

Immunity: After recovery from infection, the body may develop immunity.

Incubation period: 50-180 days

Signs and symptoms
i. Similar to that of hepatitis ‘A’. Dark urine (the colour of cola or tea), pale coloured stools (greyish or clay coloured)
ii. Progressive HBV infection may cause progressive liver disease including chronic active hepatitis and hepatocellular carcinoma.

Diagnosis
a) Liver function tests
b) Liver biopsy (Biopsy is an examination of tissue removed from a living body to discover the presence, cause or extent of a disease.)

Treatment: There is no antiviral treatment. Prevention is the main aim of managing it.

Prevention and Control
i. Hepatitis ‘B’ vaccination
ii. Proper handling of blood and blood products.
iii. Screening of blood donors.
iv. To avoid contact with blood, semen and other body fluids of patients and carriers.
v. To avoid promiscuous sex.
vi. Awareness to carriers for their generations to prevent transmission.

Hepatitis C (Non ‘A’ and non ‘B’ hepatitis)

· It has been known to cause 90-95% of cases of transfusion-associated virus (through the needles).
· Currently, there is no hepatitis ‘C’ vaccine.
· The chance of transmission is through blood and blood products.
· It is very common in Intravenous drug abusers and also occurs as a complication of blood transfusion.
· The chance of transmission is less from infected mother to child and from natural safe sex but more from unnatural unsafe sex.

Symptoms: Feel heavy on the upper left side of the stomach, get tired immediately

Diagnosis: Blood test (Anti HCV positive), PCR test, Video X-ray of the liver, Endoscopy, LFT, Prothrombin Time, Fibroscan

Treatment:
· Alpha interferon (1991 AD) - side effects, as well as reoccurrence, is common.
· Ribavarian (1998 AD)
· Alpha interferon and Ribavarian both
· Beta interferon (2001 AD)
· Teleprever and Bociprever

Hepatitis ‘D’ (Delta hepatitis)

· It is caused by Hepatitis ‘D’ virus (HDV virus).
· HDV is a defective virus for which HBV is a helper.

· Thus, hepatitis ‘D‘ develops when there is concomitant hepatitis ‘B’ infection as its genome lacks certain genes.
· Vaccine against hepatitis ‘B’ is effective.

Hepatitis ‘E’

· It is a waterborne infection.

· It was first reported in Delhi in 1955 AD.
· It spreads through contaminated water and food.

· The incubation period is of 2-8 weeks.

· Symptoms are similar to those of hepatitis ‘A’ but Bilirubin levels are usually higher.
· Jaundice is deeper and prolonged.
· Personal cleanliness, boiled water, properly heated, cooked and clean food articles and control of flies are essential in the period of epidemic.
· Vaccine is available.
· A characteristic feature of hepatitis ‘E’ infection is the high mortality rate among pregnant women (around 20%).

Hepatitis ‘G’

· It is caused by Hepatitis GB virus.

· Little is known about it.
· It has been shown that it is transmitted through blood transfusion.

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