Viral Hepatitis Flashcards
(36 cards)
1
Q
What is hepatitis E virus?
A
- HEV is RNA virus that is found worldwide but more common in LMIC
- HEV genotypes 1 and 2 are found in humans
- HEV genotypes 3 and 4 are zoonotic diseases with reservoirs in both humans and animals
e.g. pigs, monkeys, dogs
2
Q
How is hepatitis E virus transmitted?
A
- Via contaminated food and water
e.g. poor sanitation and water purification - Many animals have been identified as viral reservoirs
e.g. pig, shellfish, rodents, deer, cow - Transmission via blood transfusion may occur
- Perinatal transmission is rare and controversial
3
Q
How to prevent hepatitis E virus transmission?
A
Cooking food and boiling water inactivates the virus
4
Q
Incubation of HEV?
A
Incubation of 15-60 days
5
Q
Clinical features of HEV?
A
Most are asymptomatic or mildly symptomatic
6
Q
Liver pathology of HEV?
A
- acute hepatitis, usually self-limited
- Liver failure in a small proportion (1-5%)
- more common in pregnant women, people with malnutrition, and those with pre-existing liver disease. - Cholestatic jaundice may linger for >3 months
7
Q
Extrahepatic manifestations of HEV infection?
A
- pancreatitis
- hematological abnormalities
- neuro syndromes
e.g. GBS, aseptic meningitis, others
8
Q
HEV diagnosis?
A
- anti-HEV IgM antibodies - active infection
- anti-HEV IgG antibodies - past infection
- PCR - can detect HEV RNA in stool and serum samples
- anti-HEV IgG assays
- suffer from low specificity so if the clinical picture does not fit, a positive may be a false positive - liver biopsy
9
Q
Prevention of HEV?
A
General WASH measures
- Water Sanitation Hygiene
10
Q
What is hepatitis C?
A
- RNA virus discovered in the mid/late 1980s.
- 6 genotypes (1 to 6)
11
Q
Epidemiology of HCV?
A
Uncommon in Malawi and most of Southern Africa but worldwide causes infection in 150 million.
12
Q
Transmission of HCV?
A
- via percutaneous exposure
- IV drugs
- blood transfusions
- needlestick injury
- exposure to contaminated medical equipment or supplies
- dialysis
NB: People who inject drugs are a key pop - organ transplantation
- Rare: mother-to-child, sexual
13
Q
Risk factors for HCV infection?
A
- injection drug use
- past or current, esp. long term - HBV or HIV positive
- hx of incarceration
14
Q
HCV natural history?
A
- Acute and chronic phases of infection
- 30-60% progress from acute to chronic while the rest self-resolve.
- In chronic HCV, liver inflammation occurs slowly over several decades, and leads progressively to liver fibrosis and then cirrhosis.
- Once cirrhosis sets in there is risk of Hepatocellular carcinoma (HCC)
- Death is due to cirrhosis and/or HCC
15
Q
Acute vs chronic HCV?
A
- acute - HCV infection that develops during the first 6 months following the exposure
- chronic - HCV infection that persists beyond 6 months following the exposure
16
Q
Incubation period of HCV?
A
2 weeks to 6 months
17
Q
3 stages of acute inflammation of the liver due to hepatitis virus infection?
A
- prodromal stage
- fever, malaise, anorexia, nausea, vomiting, RUQ pain and tender hepatomegaly - icteric phase
- jaundice, dark urine, pruritis - resolution of symptoms
- usually within 4 weeks in HAV and HEV infection, can become chronic in HBV and HCV infection
18
Q
HCV tests?
A
- anti-HCV antibodies (EIA/ELISA immunoassay)
- HCV RNA (qualitative PCR)
- if anti-HCV antibody test is positive
19
Q
HCV diagnosis?
A
- Diagnosis is based on detection of HCV RNA in blood
- Usually in thousands to hundred thousand IU/ml - To reduce cost, we first do HCV antibody test
- If positive, confirm infection with HCV RNA.
20
Q
HCV Ab-positive and HCV RNA-negative explained?
A
- the patient resolved after acute infection
- s/he was cured with medications, and
- the antibody was a false positive.
In low prevalence settings
- is very common because the antibody assays are not very accurate
Note: In Malawi, it could be that most of the HCV-antibody-positive patients are HCV RNA negative
21
Q
When to do a HCV RNA test first?
A
- prior HCV infection
- immunocompromised
22
Q
How long do the HCV tests take?
A
- anti-HCV antibodies - may take as long as 6 weeks after HCV exposure to be detectable on tests
- HCV RNA - may take as long as 2-3 weeks after viral exposure to be detectable on tests
23
Q
Old HCV treatment?
A
Interferon alpha weekly subcutaneous injections plus ribavirin for 6 months
24
Q
Side effects of interferons?
A
- flu-like syndrome
- neuropsychiatric effects (fatigue, depression, suicidal ideations)
- autoimmune disorders
- hematologic problems (pancytopenia)
25
Side effects of Ribavirin?
1. teratogenic
2. can cause hemolytic anemia, cardiac events
26
Who is prioritized in treatment of HCV?
Treatment is universal, but patients with advanced liver disease and those with HIV are prioritized
27
Was the old treatment for HCV effective?
In the old way, many dropped out and only around 40% were cured
28
New treatment of HCV?
- Direct-acting antivirals (DAA) were developed in past 10 years
- DAAs are very well tolerated and achieve cure >90% of the time with 8-12-week course of daily pills
- If no cirrhosis, shorter (as little as 8 weeks), and if cirrhosis, you treat for 12-24 weeks.
29
What is hepatitis A?
RNA virus - Very common in Malawi and other LMIC
30
Transmission of HAV?
fecal-orally, usually via contaminated food
- Outbreaks can occur, when the person preparing the food is shedding the virus and not using good hygiene
31
Incubation period for HAV?
Incubation period about 21 days.
32
Clinical features of HAV?
1. Some are asymptomatic but perhaps ~70% get acute symptoms of hepatitis.
2. The illness self-resolves over a period of 2-4 months.
3. <1% develop fulminant liver failure
4. Liver failure is most likely if the person already has chronic HCV or HBV.
33
Diagnosis of HAV?
1. HAV IgM - positive
2. HAV IgG - positive is less helpful when the prevalence is high in the population
- unless you have excluded other types of viral hepatitis.
34
HAV treatment?
supportive care
35
HAV prevention?
1. WASH measures
2. A very effective and safe vaccine exists; however, not widely used in many LMIC.
- Patients with chronic HBV (HBsAg-positive) and chronic HCV (HCV RNA-positive) should be prioritized for HAV vaccine
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