Viral Hepatitis Flashcards
What questions do you ask to screen for viral hepatitis?
- Any recent travel, contact history, sexual history?
- Any illicit drug use? Exposure to needles?
- Any blood donations?
- Any tattoos?
- Eaten any undercooked meat, shellfish, canned food?
- Have you been Vaccinated against Hep A & B?
- Are you a chronic Hep B carrier?
Acute vs chronic presentation
- Hep A
- Hep B
- Hep C
- Hep D
- Hep E
Hep A- always acute
Hep B: acute / chronic presentation
- ADULT-acquired: majority (95%) do NOT get CHB
- PERINATAL infection: majority (90%) get CHB
Hep C: usually chronic presentation
- 80% of acute Hep C is SUBCLINICAL; >85% dev CHC
- Hence Hep C most commonly p/w chronic hep
Hep D: always chronic, against B/G of CHB infection
Hep E: always acute unless immunocompromised
Phase 1: Length of incubation period
- Hep A
- Hep B
- Hep C
- Hep D
- Hep E
Hep A: 2-6 weeks
Hep B/D: 2-6 months
Hep C: 1-5 months
Hep E: 2-8 weeks
What are the symptoms during the prodromal phase of hepatitis (Phase 2)?
Usually precedes jaundice by 1-2 weeks, lasts 3-5 days
Flu-like symptoms
- Anorexia, Lethargy
- N&V, arthralgia, myalgia, headache
- pharyngitis, cough
What are the symptoms during the icteric phase of hepatitis (Phase 3)?
Fever, Tender Hepatomegaly
N&V, +/- Change in bowel habits
Splenomegaly & Tender Cervical Lymphadenopathy (10-20%)
If severe – features of liver impairment
- Clinical Jaundice only in 1/3 of pt!
Pale stools, Dark urine
If fulminant: signs of ALF. Pt p/w encephalopathy
Phase 4: Length of recovery phase
- Hep A
- Hep B
- Hep C
- Hep E
Hep A/E: 2-12 weeks
Self-limiting Hep B/C: 3-4 months
Chronic hepatitis B/C: >6 months
Hepatitis A
- route of transmission
- Clinical presentation
- investigations
- Management
A/W poor water quality 🡪 F/O route (sewage)
Acute illness common in children (c/f 50% of adults). Rarely Fulminant, more common in elderly or Hep B/C pt
Dx: anti-HAV IgM (IgG used for vaccine response/past exposure)
Mx: supportive
Hepatitis E
- route of transmission
- Clinical presentation
- investigations
- Management
Spread via F/O route: uncooked meat/shellfish
Incubation: 2-8 weeks
Presentation:
- Acute illness common in children (c/f 50% of adults).
- Rarely Fulminant, more common in elderly or Hep B/C pt
- May have Neuro involvement: Bell’s palsy, GBS (Guillian-Barre), meningoencephalitis or other neuropathies
- Pancreatitis
- Arthritis
- High mortality if pregnant / immunoC 🡪 can become chronic in these pt
Dx: anti-HEV IgM, HEV RNA
Tx:
- Supportive (usually self-clearing)
- If serious: KIV ribavirin
Hepatitis B
- route of transmission
- investigations
- Management
Spread via blood or sexual contact
Dx: HDV-IgM
Tx: PEG-IFN
Hep C
- route of transmission
- clinical presentation
- investigations
- Management
RFs: IVDU (sexual/vertical transmission less common than Hep B)
Acute infection
- Of the acute infections, 80% of pt are subclinical: they may p/w simply flu-like S&S
- 10-20% of acute HCV infection presents with icteric acute hepatitis
Chronic Infection
- 50-85% of acutely Hep C become chronic carriers 🡪 Risk of Cirrhosis and HCC
Dx:
- Anti-HCV ELISA 🡪 RIBA (recombinant immunoblot assay) / EIA
- Consider PCR for HCV RNA (for HIV pt with negative EIA)
How to treat Hep C
- Old therapy: Ribavirin + Peg-INF (aka a form of INF-a)
- New: NS3/4A protease inhibitors (boceprevir, simeprevir, telaprevir), NS5B polymerase inhibitors (sofosbuvir)
- Cure is possible! – up to 95% cure 😊
Natural history of hepatitis B:
Acute infection: majority of SUBCLINICAL
- Of the acute infections, 70% of pt are Subclinical 🡪 aka they present with ______________ (hence Dx of Acute Hep B is missed)
- 30% of acute HBV infection presents with _____________
- 1% presents with __________________
Chronic infection
- ______ of adult-acquired acute Hep B becomes chronic
- _______ of perinatal (aka vertical) Hep B becomes chronic
- Hence chronic Hep B most commonly occurs in children
Its better to contract Hep B as adult than as child via vertical transmission
Of all chronic HBV 🡪 ________ leads to cirrhosis
- Usually HCC develops after cirrhosis
- However, there is ↑ HCC risk even BEFORE cirrhosis in chronic HBV infection
- HENCE: despite majority of Hep B attacks are ACUTE, most people present with CHRONIC Hep B infection instead, since majority of acute infection is subclinical
flu like symptoms;
Icteric Acute Hepatitis;
fulminant Hepatitis!
<5%;
> 90%;
20%
How is Hep B spread?
Blood, Sexual contact, IVDU, Vertical Transmission (MOST COMMON!)
Hence, highest risk of chronic status in children (>90%, c/f 20-30% in adults)
What does the window period of acute hepatitis mean?
What are the HBsAg, anti- HBs, HBcAg results
Interpretation:
- Could be from early infection before HBsAg appears
- OR Could be between disappearance of HBsAg & synthesis of Anti-HBs Ab
HBsAg -ve; Anti-HBs Ab -ve; HBcAg +ve 🡪 This means: even though pt does not have HBsAg, pt is still having infection as virus has not been cleared (no HBsAb; HBV DNA is still present in blood
What is the interpretation of this results in this patient with chronic HBV infection?
- ALT normal
- HBsAg high
- HBV DNA >10^7 IU/ mL
- HBeAg positive
- Anti Hbe Ab -ve
- none/ minimal liver disease
IMMUNE TOLERANT
Immune system tolerates infection virus multiples w no immune reaction hence no illness symptoms + no damage to liver.
This is seen exclusively in children who are infected via vertical transmission.
This is due to their weak immune system which cannot mount IR. Transits into immune active phase after decades
No reliable treatment at this stage.
What is the interpretation of this results in this patient with chronic hep B?
- HBsAg high/ immediate
- ALT elevated
- HBV DNA 10^4 IU/ mL - 10^7 IU/ mL
- HBeAg positive
- Anti Hbe Ab negate
- Moderate/ severe liver disease
Immune reactive HBeAg positive.
10-20% of these patients convert to HBeAg -ve every year.
