Hepatitis A :-
Viral hepatitis is the most common cause of hepatitis worldwide. Hepatitis is an inflammation of the liver. It is lethal and can be progressed into fibrosis (scarring), cirrhosis or liver cancer. However, the condition can be self-limiting, hepatitis is caused by hepatitis virus. there are 5 different types of hepatitis viruses, namely A, B, C,D and E. these 5 types are of greatest concern, because it is the world-wide burden apart from this other factor such as toxic substance ( e.g. alcohol, certain drugs ), and autoimmune disease can also cause hepatitis.
More particularly, types B and C lead to chronic disease in hundreds of millions of people and, together, are the most common cause of liver cirrhosis and cancer.
Hepatitis A and E are mainly transmitted by ingestion of contaminated food or water while hepatitis B, C and D usually occur as a result of parenteral contact with infected body fluids. Common modes of transmission for these viruses include receipt of contaminated blood or blood products, invasive medical procedures using contaminated equipment.
Acute infection may occur with limited or no symptoms, or may include symptoms such as jaundice (yellowing of the skin and eyes), dark urine, extreme fatigue, nausea, vomiting and abdominal pain.
Hepatitis A virus is very common in areas of the world with poor sanitation. The disease is easily transmitted to others through blood, the oral-fecal route, anal sex, and contaminated food and water. The virus travels through the bloodstream to the liver where it infects hepatocytes, cells that form the liver’s main tissue and make up most of its mass.
It is simple, made up of only nucleic acid and proteins, but it is still able to take over normal cell functions and convert them to make more viruses.
Complications: It does not cause long-term liver damage. Sudden loss of liver function. Acute liver failure is the complications of the infection.
HAV differs from other hepatitis strains because it’s member of the picornavirus family. Pincornavirus are small, non-enveloped, icosahedron-shaped virus. it is a single stranded RNA virus with icosahedron 3-diamensional figure bcontaining 20 faces resembling a soccer ball.
It contains protein and nucleic acid. The protein of the nucleocapsid, called the capsid.in some cases, the capsid helps the virus to enter inside the host and protects the virus from the host immune system. The genome only has the genes needed to shut down the host cell and make more viruses. These features of hepatitis A Virus (HAV) are described below.
The capsid of HAV is made up subunits called capsomeres as shown in figure. Each capsomere is made up of five protomers. Each protomer of HAV is made of three proteins; VPI, VP2, And VP3, which have a role in cell entry.
Genome: Figure shown the genome of HAV is a single strand of RNA that is divided into three sections. The genome of HAV is positive-sense, sin-glestranded RNA, written as ss (+) RNA. Because the virus is positive –sense RNA, it can be used as m RNA and converted (translated) into protein upon entering the cell. The genome has an at toms.
Pathogenesis: -
Source – food handler, patient, contaminated water mode of transmission
Drinking contaminated water
Eating raw shellfish from water polluted with sewage
Being in close contact with a person who’s infected –even if that person has no signs or symptoms
Sexual contact
It is not spread through sneezing or coughing
Symptoms :
Fatigue
Sudden nausea and vomiting
Abdominal pain or discomfort, especially on the upper right side beneath your lower ribs ( by your liver )
Clay- coloured bowel movements
Loss of appetite
Low-grade fever
Dark urine joint pain
Yellowing of the skin and the whites of yours eyes (jaundice)
Intense itching
Prevention: The hepatitis A vaccine can be administered to prevent infection with the virus. The vaccine is typically given in two shots. The first one is followed by a booster shot six months later. The centers for disease control and prevention recommends a hepatitis a vaccine foe following people:
All children at age 1, or older children who ditn’t receive the childhood vaccine laboratory by B
A Man who have sex with men.
People with other risk factors who work or travel in parts of the world where hepatitis A is common people who use any type of illegal drugs, not just injected ones.
People who receive treatment with clotting-factor concentrate people with chronic liver disease. If you’re concerned about your risk of hepatitis A, ask your doctor if you should be vaccinated.
Safety precautions when travelling: Peel and wash all fresh fruits and vegetables Do not intake raw or uncooked meat and fish. Avoid all beverage of unknown purity, with or without ice. If bottled water is not available, boiled tap water can be used.
Practice good hygiene: Hands should be washed thoroughly especially after using the toilet or changing a diaper and before preparing food or eating.
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