WEEK9- Trans 8 - Hepatits Viruses PDF

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MYCOLOGY AND VIROLOGY LECTURE

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HEPATITIS VIRUS

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DATE:APRIL 4,2022 PROF: ROCHELLE D. DARLUCIO-YABUT, RMT, MPH

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TOPIC OUTLINE Hepatitis A Virus (HAV) Hepatitis C Virus (HCV) Hepatitis E Virus (HEV) Hepatitis B & D Virus (HBV and HDV)

Hepatitis Viruses Involves the liver Usually, when a patient is infected with hepatitis, at early stages the patient will exhibits flu-like symptoms, such fever and headache, pain (mild to moderate) on upper-right quadrant of the abdomen (Liver) Will lead to hepatomegaly, jaundice, dark urine, light colored feces because of bilirubin Different Types of Hepatitis [They have different Families]  Hepatitis A Virus – Infectious Hepatitis  Hepatitis B Virus – Serum Hepatitis  Can be transmitted through blood  Only dsDNA  Hepatitis C Virus  Hepatitis D Virus  Hepatitis E Virus Hepatitis A and E – can be transmitted through fecal-oral Hepatits B and D - Parenteral Hepatitis A Virus Infectious hepatitis Single-stranded RNA virus, icosahedral, naked (no envelope) Genus Hepatovirus Family Picornaviridae It was first provisionally classified as enterovirus 72 Average incubation period is 2-6 week. (1 month) So called epidemic or infectious hepatitis

Blood Stool Urine Saliva, Semen

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Occurrence of Virus 2 week before to ≤ 1 week after jaundice 2 weeks before to 2 weeks after jaundice Rare Rare

Clinical and Laboratory Features Flu-Like symptoms Onset: Abrupt (within 24 hours) Fever: > 38OC (100.4oF) Duration of aminotransferase elevation (Liver enzymes such as ALT): 1-3 weeks Immunoglobulin (IgM) Levels: Elevated Complications: Uncommon, no chronicity Mortality rate (icteric cases): 85oC (185oF) for 1 minute and disinfecting surfaces with sodium hypochlorite (1:100 dilution of chlorine beach) are necessary to inactivate HAV.  Since it can be transmitted through fecal-oral Laboratory Diagnosis Clotted venous blood, 5-10 mL  We will get the serum and check for the IgM and IgG Hepatitis A IgM (IgM is marker of acute infection)  Becomes positive 5 days after the onset of symptoms  Positive up to 4-6 months Hepatitis A IgG  Becomes positive from a week after onset of illness or receiving hepatitis A vaccination and persists throughout life.  When detected alone, for example without IgM, it signifies immunity to infection due to either past infection or vaccination. Feces PCR for hepatitis A virus

Treatment Treatment is supportive Fulminant Hepatitis – When liver begins to fail and not function correctly  Liver transplantation may be indicated

Pre-exposure Prophylaxis (Prevention)  Killed Hepatitis A virus vaccine is available.  Two doses given one year apart offer for up to 10 years.  A booster may be required at 10 years but recent evidence suggests that the two doses will give lifelong protection. Post-exposure Prophylaxis (Exposed Already)  Normal human immunoglobulin and/or hepatitis A vaccine should be given to household contacts within 14 days of exposure.  Immune(gamma) globulin (IG): given within 1-2 weeks after exposure to hepatitis A Disease

Components of System HAV

Hepatitis A

Anti-HAV IgM antiHAV

Definition Hepatitis A virus. Etiologic agent of infectious hepatitis. A picornavirus, the prototype of genus Hepatovirus Antibody to HAV. Detectable at onset of symptoms; lifetime persistence IgM class antibody to HAV. Indicated recent infection with

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MYCV311

HEPATITIS VIRUSES hepatitis A; positive result up to 4-6 months after infection.

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Hepatitis C Virus Hepatitis C virus is a single-stranded RNA virus Family Flaviviridae Genus Hepacivirus The resulting diseases was termed non-A, non-B (NANB) Hepatitis. Common cause of post transfusion hepatitis  Can be acquired through blood The average incubation period is 2-6 weeks, but may be as long as 3 months Route of Infection  Predominantly parenteral – through inoculation of needle, blood transfusion, and etc Infectious throughout their lifetime Route of Spread Blood and blood product transfusion Intravenous drug use Iatrogenic (through medical treatment)  If the medical equipment are not thoroughly sterilized Organ and tissue donation from infected donors  That why we need to make sure that the donors do not have communicable diseases Renal dialysis, if proper precautions are not followed. Infection can be transmitted after a sharps or needlestick injury from an infected source patient to an HCW. Ear and body piercing, tattooing Sexual, and vertical (from mother to baby) transmission

Acute and Chronic HCV Infection Acute infections are asymptomatic Malaise, fatigue, nausea and jaundice

Chronic HCV Infection  Develop cirrhosis of the liver after 20-30 years, a small proportion of whom will develop hepatocellular carcinoma.  Cirrhosis is a major risk factor for hepatocellular carcinoma.

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For Establishing Infection Patient for Treatment  Hepatitis C PCR for HCV RNA.  Mostly quantitative (viral load) assay  Positive result indicates either acute or chronic infection.  Negative result indicates clearance of infection either naturally or post-treatment. Assessment of Infected Patient for Treatment  EIAs that detect serum antibodies to HCV proteins are available as screening tests  Antibodies are directed against core. Envelope, and NS3 and NS4 proteins and tend to be relatively low in titer.

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Screening for Acute or Chronic HCV Infection  5-10 mL of clotted venous blood – get the serum because of antibodies  Hepatitis C Antibody Positive: Indicated infection, initial screen MUST be confirmed by repeat testing.

Hepatitis E Virus Hepatitis E Virus is a small (32 to 34 nm), naked, ssRNA Virus Genus Hepevirus  Previous classification: Calicivirus Family Hepeviridae/Hepadnaviridae Naked, icosahedral capsid Agent of enterically transmitted hepatitis

Genotypes  Genotypes 1 and 2 are limited to humans only  Genotypes 3 and 4 have animals as their reservoir and therefore are zoonotic infections  Genotype 3: U.S. Avian HEV: Chickens Swine: Worldwide Wild Deer: Japan

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 Laboratory Diagnosis Anti-HCV EIA: screening  Anti- means you have the presence of antibodies  Antibodies are usually checked in serologic tests Anti-HCV immunoblot RT-PCR and Quantitative branched chain DNA: Viral therapy monitoring HCV RNA: should be negative after 6 months of therapy

There is no HCV specific IgM test available to distinguish acute from chronic infection.

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Route of Spread Hepatitis E is spread by the fecal-oral route, mostly through drinking water and probably by eating contaminated food. Waterborne The average incubation period is 6 weeks Self-limiting viral hepatitis  Almost the same with hepatitis A virus  Early symptoms have flu-like symptoms High Fatality rate among pregnant women: 3rd Trimester of pregnancy  Fulminant Hepatitis Laboratory Diagnosis Dark urine, pale feces, jaundice Increased Liver enzymes

Acute Hepatitis  Clotted Venous Blood, 5-10mL – serum then check for IgG and IgM  Hepatitis E IgM o Becomes positive within first week of acute hepatitis and remains positive for up to 3 months. o Signifies acute infection  Hepatitis E IgG o Becomes positive from 1 to 2 weeks after onset of illness.

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HEPATITIS VIRUSES

When detected alone, for example without IgM, signifies immunity to infection due to past infection. Treatment Treatment is supportive Fulminant Hepatitis: Liver transplantation may be indicated There is no vaccine or passive prophylaxis available o

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Hepatitis B (and D viruses) Hepatitis B virus (HBV) us a member of the Hepadnaviridae family of viruses, and has a doublestranded circular DNA and a DNA polymerase enzyme Serum Hepatitis Two Major Proteins

Hepatitis B surface antigen (HBS Ag) Hepatitis B Core Antigen

Hepatitis Be Antigen (HBe Ag)

An outer protein expressed in an excess when the virus replicates in the liver An inner protein, which is expressed only within hepatocytes in the liver. Other Proteins Envelope Antigen.Also shed in the blood when the virus replicates, and its presence (Positive) is associated with high infectivity. Marker of High Infectivity

persistent hepatitis, chronic hepato-cellular carcinoma.

Hepatitis D Virus  Hepatitis D Virus (HDV) is a defective DNA virus, which cannot replicate in humans in the absence of HBV.  Patients can be co-infected with HBV and HDV, or HBV infected patients can be super-infected with HDV.  Co-infection – having both diseases (HBV and HDV)  Super Infection – After a long term period the patient develops HDV

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Component of System HBV

HBsAg

HBeAg Hepatitis B

HBcAg Anti-HBs

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Incubation period Infection can develop from 6 weeks to 6 months after exposure to the virus.

Acute Hepatitis B Acute infection is accompanied with a rise in ALT (Alanine Aminotransferase) of >500 IU/L and jaundice. Fulminant hepatitis (Defect on Liver) and death 95% of adults clear the virus within 6 months after an acute infection.

cirrhosis,

Serologic Markers for the Diagnosis of Hepatitis B Virus Infection Hepatits B surface antigen, the envelope protein consisting of three polypeptides; First marker to appear at the end of incubation period (Time when the patient is infected with the virus until the presence of signs HBsAg and symptoms. During incubation period we cannot perform serologic tests because there are no signs and symptoms, and antibodies.) Antibody to Hepatitis B surface Antigen; Appears at the end of the acute stage; The HBsAg will eventually decrease and the Anti-HBs body will produce antibody; Also indicates immunity. When you have vaccine, you will be positive in Anti-HBs. Antibody to Hepatitis B core Antigen; indicates Anti-HBc the convalescent stage, or recovery Hepatitis B Envelope Antigen. Antigen associated with the nucleocapsid, also found as HBeAg soluble protein in serum. Indicates active viral replication. When the patient is positive in HBeAg, the patient is most infectious. Antibody to hepatitis B e Antigen; Indicates Anti-HBe that the infection is resolving. Disease

Route of Spread Parenteral (Blood Exposure) Sexual Vertical (From Mother to Baby).

hepatitis,

Anti-HBe

Anti-HBc

IgM antiHBc

Definition Hepatitis B Virus. Etiologic agent of serum hepatitis. A hepadnavirus Hepatitis B surface antigen. Surface antigen(s) of HBV detectable in large quantity in serum; several subtypes identified Hepatitis B e Antigen. Associated with HBV nucleocapsid; indicates viral replicates; circulates as soluble antigen in serum Hepatits B core antigen Antibody to HBeAg. Presence in serum of HBV carrier suggests lower titer of HBV Antibody to HBeAg. Presence in serum of HBV carrier suggests lower titer to HBV Antibody to HBcAg. Indicates infection with HBV at some undefined time in the past. IgM class antibody to HBcAg. Indicates recent infection with HBV; positive result for 4-6 months after infection

Treatment (for Hepatitis B)  

Chronic Hepatitis B Persistence of hepatitis B infection beyond a period of 6 months subsequent to acute infection. Failure to clear the virus may lead (over a period of several years) to progressive liver damage with

Acute Hepatitis B  Acute infection is self-limiting and 95% of immunocompetent adults clear the virus within 6 months of onset of acute hepatitis.

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Chronic Infection  A small number of patients will spontaneously clear the virus, with 10-15% of HBe Ag positive patients per year seroconverting to anti-HBe positive status and then over a period of time clearing the virus altogether.

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HEPATITIS VIRUSES

Fulminant hepatitis may occur in...