L ETS BACK TRACK A L ITTLE : During the past three or more centuries “epidemic jaundice” or viral hepatitis A has been recognised as an important millitary disease,especially during periods of war.Outbreaks were recorded in Germany in 1692 and in the British Army in Flanders in 1743.Other epidemics occurred during Boer War in South Africa and in the Japanese Navy.This trend continued during the course of all subsequent conflicts.
A N OUTLINE Types : seven Namely Hepatitis A,B,C,D,E,F and G The causative agent can either be a DNA or RNA virus, enveloped or non-enveloped. he deadliest of all is Hepatitis C while Hepatitis B is reputed to be the most infectious. he most common : HAV,HBV,HCV. Most of the symptoms and diagnostic techniques are common to all types.
Also known as infectious hepatitis, first identified in 1973. Caused by HAV non-enveloped RNA virus Contains a positive sense single-stranded RNA packaged in a protein shell. Family : Picornaviridiae Size : 27-32 nm in diameter Serotype : only one known type Genotypes : I, II and III
TREATMENT Hepatitis A usually clears up on its own and does not require any treatment. However patients should:- Get plenty of rest. Avoid drinking alcohol. Avoid eating food enriched with fatty acids. Take nutritious food.
P REVENTION Two vaccines:- “Havrix” “VAQTA” The vaccine is given in series of two shots. Second shot is given 6-8 months after first shot. Protection starts after 2-4 weeks of first shot Second shot of vaccine is for long term protection(20 years).
♦ Also known as “SERUM HEPATITIS” ♦ It is caused by enveloped DNA virus ♦ Family : HEPADNAVIRIDAE ♦ Genome : partially double stranded,circular DNA. ♦ Size : 42nm ♦ Capsid Shape : Icosahedral ♦ Genotypes : 8 i.e., A-H ♦ Serotypes : 4 i.e, adr,adw,ayr and ayw
♦ It is hundred times more infectious than HIV. ♦ About 1/3 of the population is suffering from Hepatitis B. ♦ Approx. 1.2 million people die each year. ♦ HBV is able to survive in dried blood for longer than 1 week. ♦ Its virion particle is also called DANE particle. ♦ The receptor site is still unknown
MODE OF TRANSMISSION ♦ Mainly transmitted through body fluids such as urine,semen,vaginal fluids and blood. ♦ Blood transfusion ♦ Reuse of needles ♦ Sexual contact
SYMPTOMS ♦ 50% of Hepatitis B patients don’t show any symptoms. ♦ Symptoms develop within 30-180 days of exposure to virus. ♦ It usually has flu-like symptoms. ♦ Other symptoms as mentioned for Hepatitis A.
♦ Blood test ♦ CT scan and Ultrasound ♦ Liver biopsy
TREATMENT ♦ Acute patients can recover on their own without any treatment. ♦ For chronic patients ANTIVIRAL MEDICATIONS are required such as:- ♦ ALFA-INTERFERON:- slows down viral ability to liver damage. ♦ LAMIVUDINE:- inhibits viral DNA synthesis
BARACLUDE:- It is the latest known anti-viral drug for the treatment of chronic Hepatitis B that inhibits DNA polymerase activity.
PREVENTION ♦ Hepatitis B vaccine boosts up immune system. ♦ Can be given to any age group. ♦ 3 doses for 6 months. ♦ Hepatitis B immune globulin plus Hepatitis B vaccine combination prevents chronic Hepatitis B in about 70% of the patients. ♦ Avoid unsanitary tattoo methods. ♦ Avoid unsanitary body piercing methods. ♦ Avoid needle stick injury.
♦ 2 billion people suffer from Hepatitis B worldwide. ♦ 350 million are chronic Hepatitis B patients.
o Also known as non-A,non-B Hepatitis, discovered in 1989. o Causative agent : Hepatitis C virus,an enveloped RNA virus. o Viral genome : positive sense, single stranded RNA o Family : Flaviviridae o Size : 55-65 nm o Structure:- Capsid shape : Icosahedral
o Envelope : lipid envelope of cellular origin. o Glycoproteins : E1 and E2 are embedded in the lipid envelope. o Genotype : 6 but genotype 1 is the most difficult to treat. o Gene codes : HCV codes for 10 different genes.
MUTATION o Evolutionary mutation i.e., different genotypes from 1-6. o Quasispecies: Genetic variants. It is the mutation in a single genotype of HCV RNA within the infected host. o Heterogenous character is most evident in hypervariable region 1(HVR 1) of the envelope gene. o Role of Heterogeneity in Quasispecies: viral persistence cellular tropism and pathogenesis of hepatic disease response to antiviral therapy
S TEPS INVOLVED IN LIVER DAMAGE DURING HEPATITIS C INFECTION
RISK FACTORS, MODE OF TRANSMISSION AND PREVENTION o Majorly transmitted through blood o Haemophilic majorly before 1987 o Injected drugs o Long term kidney dialysis o Organ transplant before July 1992 o HCV mother to child o Tatoos,body peircing o Sexual transmission =low o Health care workers
SYMPTOMS o Mostly asymptomatic but symptoms may appear during liver cirrhosis. o Fluid retention causing swelling of the belly(ascites) legs or whole body. o Persistance jaundice. o Disturbance in sleeping. o Vomitting with blood in it. o Mental disturbance such as confusion, lethargy and extreme sleepiness o Difficult blood clotting.
TESTS AND DIAGNOSIS o Blood screening o ELISA o RIBA (recombinant immunoblot assay) o Hepatitis C RNA assay o Liver biopsy Note: Blood test show elevated levels of liver enzymes, a sign of liver damage.
TREATMENT o No vaccine available yet. o Drugs : combination therapy of pegylated interferon and ribavirin. o Different patterns of responses to antiviral treatment Note : Response to treatment may vary based on individual factors,genotype,viral load. Highest response shown by genotype 2 and 3 infected patients, least by genotype 1 and 4.
o 200 million are infected with HCV worldwide. o In Pakistan out of 180 million about 10 million people are infected with HCV.