Hepatitis A Testing and Diagnosis

Hepatitis Testing

• Detecting antibodies and antigens in patient sera aids in pinpointing the virus responsible, the stage of infection, and the patient's immune status.
• ELISA, or Enzyme-Linked Immunosorbent Assay, is a commonly employed test method.

Hepatitis A

• HAV belongs to the Picornaviridae family.
• Transmitted via the fecal-oral route and spreads through fecal contamination of food or water, causing epidemics.
• Infections can be asymptomatic, especially in children, or symptomatic.
• Incubation takes about 10-50 days.
• Symptomatic infections manifest as fever, anorexia, vomiting, fatigue, abdominal pain, malaise, and jaundice, with pregnant women experiencing more severe symptoms.
• Recovery generally occurs within 2-4 weeks, mortality rate stands at 0.1%, and chronic disease is rare.
• Inactivated vaccines, available since 1995, benefit travelers, drug abusers, and children.
• Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels rise, peaking before jaundice occurs, along with hyperbilirubinemia, decreased albumin, tea-colored urine, and pale stools.
• Paired sera, collected at the onset of symptoms and 3-4 weeks later, assess the increase in anti-HAV antibodies or a single acute sample with a higher titer of IgM over IgG suggests acute infection.
• Anti-HAV antibodies appear at the onset of symptoms and persist for years.

Hepatitis B

• HBV is a partially double-stranded DNA virus belonging to the Hepadnaviridae family.
• The Dane particle represents the complete HBV virus (42 nm) that causes infection.
• HBV transmits through mucous membranes (sexual contact), wounds contacting contaminated blood/body fluids, parenteral routes like transfusions, hemodialysis, IV drug use, contaminated needles, tattoos, acupuncture, or ear piercing.
• High-risk groups include IV drug users, men with men, hemodialysis patients, and healthcare workers.
• Incubation period is 50-180 days.
• Symptoms include fever, anorexia, vomiting, fatigue, malaise, jaundice, and arthralgia.
• Acute infection can extend up to 6 months, with most patients recovering within this timeframe.
• About 5% develop chronic infections, remaining HBsAg positive, which can lead to severe liver damage, cirrhosis, or hepatocellular carcinoma if active.
• All chronic carriers shed the virus.
• Recombinant HBV vaccine recommended for healthcare workers and routine vaccination for all children in the U.S.
• HBsAg appears first, peaking midway through acute infection, indicating infectivity.
• HBeAg appears soon after HBsAg, peaking at same time, disappearing about two-thirds through the acute infection phase.
• Antibody to hepatitis B core (anti-HBc) rises weeks into acute infection, peaking at the end, then falls below detection before anti-HBs appears, marking the "core window."
• Anti-HBc IgM peaks weeks after acute infection, disappearing in about 6 months during recovery whilst Anti-HBc IgG persists for decades.
• Anti-HBe rises and peaks 2-16 weeks later at the end of the acute stage, decreasing slightly over time.
• Anti-HBs appears at the end of the acute stage and beginning of recovery, peaks and never disappears, indicating immunity.
• Those with chronic infections do not produce detectable anti-HBs, HBsAg persists, making them carriers at risk for cirrhosis and hepatocellular carcinoma.

Hepatitis C

• HCV is a single-stranded RNA virus belonging to the Hepacivirus family.
• Parenteral transmission is most widespread, with sexual and perinatal transmission being less common.
• Incubation takes 2-26 weeks.
• Acute infections are asymptomatic or mild, causing nausea, vomiting, abdominal pain, fatigue, malaise, and jaundice.
• 50-80% of cases progress to chronic, with 25% leading to cirrhosis, with about 20% of these cirrhosis cases developing into cancer.
• Anti-HCV indicates HCV infection, but anti-HCV IgM does not differentiate between acute and chronic infections as both IgM and IgG antibodies persist for years.

Delta Hepatitis

• HDV is an unclassified, single-stranded RNA virus that requires HBsAg from HBV infection to replicate.
• Globally spreads via parenteral and transmucosal routes.
• Coinfection occurs when patients concurrently acquire HBV and HDV.
• Superinfection occurs when those with established HBV acquire HDV, potentially progressing to chronic HBV/HDV infection.
• Chronic HBV/HDV infection implies severe liver damage, inflammation, and cirrhosis with poor prognosis, which can be prevented via HBV vaccination.
• HBsAg positive patients tested for HDV.
• HDV-Ag is the earliest marker, appearing 1-4 days before symptoms.
• IgM anti-HDV appears, followed by low levels of IgG anti-HDV, with a switch to high levels of IgG indicating past HDV infection.

Jaundice

• Jaundice is defined by yellow skin, whites of the eyes and mucous membranes due to a high level of bilirubin.

Liver cirrhosis

• A condition of scarring and permanent liver damage.

Hepatitis A Transmission, Prevention and Treatment

• Transmission: Eating contaminated food or drinking contaminated water
• Prevention: Practicing good hygiene, Vaccine
• Treatment: No treatment

Hepatitis B Transmission, Prevention and Treatment

• Transmission: Contact with the blood or bodily fluids of an infected person
• Prevention: Practicing good hygiene, Vaccine, Blood screening
• Treatment: Alpha interferon, Peginterferon

Hepatitis C Transmission, Prevention and Treatment

• Transmission: Blood-to-blood contact
• Prevention: Practicing good hygiene, Avoid sharing needles, toothbrushes, razors or nail scissors
• Treatment: Direct-acting antiviral drugs

Hepatitis D Transmission, Prevention and Treatment

• Transmission: Contact with infected blood (only occurs in people already infected with hepatitis B)
• Prevention: Hepatitis B vaccine, Avoid sharing needles, toothbrushes, razors or nail scissors
• Treatment: Interferon

Hepatitis E Transmission, Prevention and Treatment

• Transmission: Eating contaminated food or drinking contaminated water
• Prevention: Practicing good hygiene, Avoid drinking water that has come from a potentially unsafe source
• Treatment: No treatment