39 - Viral Infections of the GI Tract I Flashcards
1
Q
What is hepatitis?
A
A disease marked by inflammation of the liver
2
Q
What are the three main clinical presentations of hepatitis?
A
- Acute hepatitis
- Chronic hepatitis
- Fulminant hepatitis
3
Q
What are the symptoms of acute viral hepatitis?
A
- Jaundice
- Dark urine
- Alcoholic stool
- Prodrome
4
Q
What is “alcoholic stool”?
A
A light or clay-colored stool due to reduction in bile production
5
Q
What is prodrome?
A
1-2 weeks prior to jaundice
- Headache
- Myalgia
- Arthralgia
- Fatigue
- Nausea
- Vomiting
- Pharyngitis
- Mild fever
6
Q
Why do we see jaundice?
A
Because bilirubin is not properly recycled, so it is elevated in the body
7
Q
What do we define jaundice as?
A
More that 3 mg/dL of bilirubin
8
Q
What does bilirubin in the urine indicate?
A
Liver disease
9
Q
What liver enzymes will be elevated in hepatitis?
A
ALT: alanine aminotransferase
AST: aspartate aminotransferase
10
Q
When will these enzymes become elevated?
A
In the prodrome phase
11
Q
Are these enzymes typically more elevated in a viral infection or in hepatitis from alcoholism, etc.?
A
Higher in viral infection
12
Q
How do we define chronic viral hepatitis?
A
- Hepatitis which does not resolve within 6 months
13
Q
What does chronic viral hepatitis predispose individuals to?
A
Hepatocellular carcinoma and cirrhosis
14
Q
What phases would someone in chronic viral hepatitis go through?
A
There is damage, but also regeneration, so you can go through phases of better and worse
15
Q
What is fulminant viral hepatitis?
A
Rapid and severe hepatitis which results in massive hepatic necrosis
16
Q
What else does fulminant viral hepatitis cause?
A
- Encephalopathy
- Edema
- GI bleeding
- Sepsis
- Organ failure
17
Q
What does the encephalopathy cause?
A
CNS effects
- Confusion
- Disorientation
- Coma
Cerebral edema can compress the brainstem
18
Q
What is something that can be lifesaving to patients with fulminant viral hepatitis?
A
Liver transplant
19
Q
What are the five types of hepatitis?
A
Hepatitis A Hepatitis B Hepatitis C Hepatitis D Hepatitis E
20
Q
What virus family is Hepatitis A from?
A
Picornavirus
21
Q
What is the invubation period for Hepatitis A?
A
2-4 weeks
22
Q
What is the transmission type for both Hepatitis A and Hepatitis E?
A
Fecal-oral route
23
Q
What else do Hepatitis A and Hepatitis E have in common?
A
Neither can cause a chronic infection
24
Q
What is the virus family for Hepatitis B?
A
Hepadnavirus
25
What is the incubation period for Hepatitis B?
6 weeks to 6 months
26
What type of transmission do we see for Hepatitis B, Hepatitis C and Hepatitis D?
Body fluids
27
What else do Hepatitis B, Hepatitis C, and Hepatitis D have in common?
They can cause a chronic infection
28
What virus family is Hepatitis C from?
Flavivirus
29
What is the incubation period for Hepatitis C?
2 months
30
What is the virus family for Hepatitis D?
Deltavirus
31
What is the incubation period for Hepatitis D?
2 to 12 weeks
32
What is the virus family for Hepatitis E?
Hepevirus
33
What is the incubation period for Hepatitis E?
6 to 8 weeks
34
Which Hepatitis virus is the ONLY one with a DNA genome?
Hepatitis B
All the others have a RNA genome
35
What age groups are most susceptible to Hepatitis A?
All age groups
Children are usually asymptomatic
36
How long does it typically take to resolve an infection from Hepatitis A?
2 months
37
Can Hepatitis A cause fulminant hepatitis?
Very rarely
38
How do you diagnose Hepatitis A?
Test for IgM antibodies against the Hepatitis A virus
39
Why wouldn't you want to test for IgG antibodies against Hepatitis A virus?
Because these are protective immunity and are normally present (does NOT indicate an infection)
40
How do we prevent Hepatitis A?
Vaccination
The inactivated vaccine has been available since 1995
Two IM doses, universally recommended for infants
41
What can you do prophylactically after an exposure?
Vaccinate or give anti-HAV IgG antibodies
42
What is unique about the Hepatitis B virus?
is has a partially dsDNA genome
43
What does this allow to be part of the viruses life cycle?
Reverse transcription
Not a retrovirus though
44
How do you diagnose Hepatitis B?
- Viral antigens and anti-HBV antibodies
45
What marks an active infection?
HBsAg (HB=hep B, Ag=antigen) in the blood
46
When would you see Hepatitis B antigens in the blood (HBsAg)?
Acute infection
| Chronic infection
47
When would you see antibodies for the Hepatitis B antigen in the blood?
(anti-HBsAg)
Vaccinated individuals
| Previously infected individuals
48
When would you see IgM antibodies against Hepatitis B?
Acutely infected only
49
When would you see all antibodies against Hepatitis B?
Acutely infected
Chronically infected
Previously infected
50
What are some ways that Hepatitis B can be transmitted through body fluids?
- Sexual
- Needle stick
- Perinatal
51
What percentage of infected adults are asymptomatic?
50%
52
Are the acute symptoms of Hepatitis A or Hepatitis B more severe?
Hepatitis A
Acute hepatitis symptoms of Hepatitis B are often milder than Hepatitis A
53
What are Hepatitis B infected individuals at risk for?
Chronic infection
54
What is the risk of chronic infection correlated with?
Age at the time of infection
The younger the individual is, the higher the risk of chronic infection
55
How do we treat acute Hepatitis B?
There is no treatment for the acute infection
56
How do we treat chronic Hepatitis B?
- Lamivudine (reverse transcriptase inhibitor)
- Famcyclovir/Adefovir dipivoxil (nucleoside inhibitor)
- Interferon-alpha
57
What does a vaccine for Hepatitis B contain?
Purified HBsAg protein
58
How soon after birth of an infant exposed to Hep B during labor would you want to give the vaccine?
Within 12 hours
Along with HBIG
59
What is the difference between premature births and full term births interms of Hep B treatment?
If you don't know it the mother was Hep B positive or not and the infant was premature, you give the treatment as a precaution
If the baby is full term, only give the treatment if you knwo the mother is Hep B positive
60
When else would you give this preventative treatment?
Health care worker exposure
61
Do we test donated blood for Hep B?
YES
- Hep B surface antigen
- Hep B core antibody
Also, the general test for hepatitis is ALT elevation
Hep C is the other one that is specifically tested for
62
What is Hepatitis C typically associated with?
Injection drug use
It is estimated that 45% of injection drug users between 18 and 45 have Hepatitis C
63
How else can you get Hepatitis C?
- Tatoos
- Needle sticks
- Perinatal transmission
- Sexual encounters
64
How do you diagnose Hepatitis C?
- Screening test - antibody test for anti-HCV antibodies
| - Confirmatory test - neucleic acid based tests for detection of the viral genome
65
In what order will you be able to detect Hepatitis C from laboratory results?
1 - Hepatitis C virus RNA
2 - ALT elevation
3 - Anti-Hepatitis C virus antibodies
66
Is the acute disease from Hepatitis C more or less severe than Hepatitis A and B?
Less severe
67
How do you treat Hepatitis C?
It depends on the genotype of chronic Hepatitis C that your patient has
68
How do you treat chronic genotype I Hepatitis C virus?
Three options
1 - ledipasvir/sofosbuvir
2 - paritaprevir/ritonavir/ombitasvir, dasabuvir, and ribavirin
3 - sofosbuvir and simeprevir ± ribavirin
KEY drug: Sofosbuvir
69
How do you treat chronic genotype II or III Hepatitis C virus?
sofosbuvir and ribavirin
KEY drug: Sofosbuvir
70
How do you treat chronic genotype 4, 5 or 6 Hepatitis C virus?
No guidelines
71
What drug do you need to remember for the treatment of chronic Hepatitis C
Sofosbuvir
72
Why is there controversy over Hepatitis C treatment?
$84,000 for a 12-week course of treatment
That's $1000 per pill
73
How do we prevent Hepatitis C?
No vaccine available
- Reduce risky behaviors
- Screen blood donation supply
74
How do we screen blood for Hepatitis C?
- Nucleic acid test
- Hepatitis C antibody test
- ALT elevation (general)
75
What is unique about Hepatitis D?
It only infects cells that have been previously or are currently infected with Hepatitis B
76
What types of proteins does Hepatitis D encode?
- Delta short antigens
- Delta long antigens
These proteins cover the virion
77
What type of virus does this make Hepatitis D?
A unique helper-dependent virus
78
How do Hepatitis B and Hepatitis D interact?
Hepatitis B surface antigen forms the external surface of the virion.
Replication of Hepatitis D requires Hepatitis B
79
What percent of Hepatitis B patients are infected with Hepatitis D?
5%
80
What is more likely when someone is infected with both Hepatitis B and D?
Fulminant hepatitis
81
What is very unique about the pathogenesis of Hepatitis D?
It is the ONLY hepatitis virus that directly injures hepatocytes
82
How do we diagnose a Hepatitis D infection?
ELISA to detect Hepatitis D antibodies or the delta antigens on its surface
83
How do we treat Hepatitis D?
No specific recommendation
84
How do we prevent Hepatitis D?
Prevent Hepatitis B
85
How is Hepatitis E transmitted?
Fecal-oral route
86
Can Hepatitis E cause a chronic infection?
No
87
What are most cases in the US associated with?
Recent travel
88
What areas do we see epidemics of Hepatitis E?
- India
- Pakistan
- Nepal
- Burma
- N Africa
- Mexico
89
What population is at high risk for fatality from Hepatitis E?
Pregnant women - etiology is unknown
90
How do we treat Hepatitis E?
Supportive
91
How do we prevent Hepatitis E?
Clean water and proper food handling
