Hepatitis B

Question 1

What is the vertical transmission rate of HBV in women with HBeAg+?

Answer 1

95%

Question 2

What is the vertical transmission rate of HBV in women who are HBsAg+ but HBeAg-?

Answer 2

25%

Question 3

What is the vertical transmission rate of acute HBV in the third trimester?

Answer 3

90%

Question 4

Without intervention, what percent of newborns infected with HBV develop chronic hepatitis? How many develop complications?

Answer 4

90%, with 25% of chronic HBV carriers eventually dying of complications (cirrhosis, hepatocellular cancer)

Question 5

What vaccines do newborns born to women with HBV receive? Efficacy?

Answer 5

HBIg, HB vaccine, within 12 hrs of birth, prevents 90% of neonatal HBV infection

Question 6

Is breastfeeding contraindicated in HBV+ mothers?

Answer 6

Breast-feeding is not contraindicated, as long as the mother is HBeAg- and HIV-, and the newborn receives appropriate immunoprophylaxis.

Question 7

Labs for serologic diagnosis of acute HBV

Answer 7

HBsAg+, HBcAb+, HBcIgM+, HBsAb–

Question 8

Labs for serologic diagnosis of chronic HBV

Answer 8

HBsAg+ >6 months, HBsAb–

Question 9

Differential diagnosis of hepatitis

Answer 9

Hepatic A, B, or C virus
Cytomegalovirus (CMV)
Epstein–Barr
Varicella (VZV)
Coxsackie B
Herpes (HSV)
Rubella
Autoimmune

Question 10

Diagnosis of newborn HBV

Answer 10

Detection of persistent (e.g., >9 months of age) HBsAg. Only HbsAb is attributable to newborn vaccination: HBcAb arises only as the result of actual HBV infection.

Question 11

Symptoms of acute HBV

Answer 11

Only 30% to 50% of patients acutely infected have symptoms such as loss of appetite, malaise, nausea, and vomiting. About 10% have jaundice. The onset is usually insidious.

Question 12

Natural history of HBV infection

Answer 12

One-third of the world’s population (two billion people) have been infected with HBV: 90% have complete resolution, while about 10% overall develop chronic HBV infection; but this incidence is 90% in children 5 years old. About 25% of HBV chronic infection patients die of liver disease (4000/yr in the United States, >1 million/yr world-wide—0.5% mortality)

Question 13

HBV vaccine efficacy

Answer 13

The vaccine is about 95% effective against HBV.

Question 14

HBV incubation period

Answer 14

60-90 days

Question 15

HBV antigens

Answer 15

“s” surface—infected. If present >6 months = chronic HBV infection
“c”—core
“e”—infectious

Question 16

HBV antibodies

Answer 16

“s”—immune

“c”—covers “window” period, and usually precedes HBsAb conversion

Question 17

Risk of chronic HBV infection

Answer 17

About 5% of HBV infections become chronic. This can lead to cirrhosis, hepatocellular carcinoma, and death.

Question 18

Interpret this HBV panel:
HbsAg -
Anti-HBc -
Anti-HBs -
Vertical transmission rate?

Answer 18

Susceptible

0%

Question 19

Interpret this HBV panel:
HbsAg -
Anti-HBc +
Anti-HBs +
Vertical transmission rate?

Answer 19

Immune bc of natural infxn

0%

Question 20

Interpret this HBV panel:
HbsAg -
Anti-HBc -
Anti-HBs +
Vertical transmission rate?

Answer 20

Immune bc of HB vaccine

0%

Question 21

Interpret this HBV panel:
HbsAg +
Anti-HBc +
Anti-HBc IgM +
Anti-HBs -
Vertical transmission rate?

Answer 21

Acutely infected
First trimester: 10% 
Third trimester: 90% 
HBeAg -: 10–20% 
HBeAg +: 90%

Question 22

Interpret this HBV panel:
HbsAg +
Anti-HBc +
Anti-HBc IgM -
Anti-HBs -
Vertical transmission rate?

Answer 22

Chronically infected
HBeAg -: 2–10%
HBeAg +: 90%

Question 23

Interpret this HBV panel:
HbsAg -
Anti-HBc +
Anti-HBs -

Answer 23

Four interpretations possible:

1. May be recovering from acute HBV infection
2. May be distantly immune and test is not sensitive enough to detect very low level of anti-HBs in serum
3. May be susceptible with false-positive anti-HBc
4. May be an undetectable level of HBsAg present in the serum and the person is actually a carrier

Question 24

Blood transfusion HBV transmission risk

Answer 24

1/137,000 transfused units of screened blood

Question 25

HBV risk factors

Answer 25

``` Intravenous drug abuse Sexually transmitted diseases Multiple sex partners House contacts Metal institution/prison Acupuncture are other risk factors HBV-infected patients are at higher risk of HIV and HCV infections. ```

Question 26

Complications of HBV

Answer 26

- Ninety percent of patients resolve the infection (clear the s and e Ag) and develop HBsAb - 10% develop chronic HB (maintain HBsAg). Of these, most are asymptomatic with normal liver function tests (LFTs), and no HBV detectable by PCR. - The other 15% to 30% of chronic HB has persistent viral replication: these patients can develop cirrhosis and hepatocellular cancer. Mortality is 0.5% to 1%. This is more common in pts coinfected with HCV or HIV.

Question 27

Lamivudine for HBV - efficacy, dosing

Answer 27

-FDA category B - >95% efficacy to achieve <150,000 HBV DNA, 167% HbeAg negativity -Can reverse cirrhosis of the liver. Given usually as 100 mg from 28 weeks to one month after birth in HBV carrier mothers, has been associated with a significant decrease in the HBV mother-to- child transmission

Question 28

How to treat HBV exposure in pregnancy

Answer 28

Check serologies, LFTs. If HBsAg- and sAb-, give HBIg and begin the HB vaccine series (preferably within 24 hours of exposure): this combination will prevent 75% of transmission. Must give HBIg within 14 days of sexual contact. Repeat HBIg within one month if blood or mucous membrane exposure.

Question 29

What is HDV?

Answer 29

Incomplete RNA virus, which can super- infect 20% to 25% of chronic HBV-infected patients. HDV infection worsens chronic HBV infection, so that 25% may die from disease. If HBV is prevented, HDV infection is prevented too. HDV has no effect on pregnancy or fetus/ neonate.

Question 30

Presence of HBeAg indicates:

Answer 30

Active viral replication and a high level of infectivity.

Question 31

When should you start lamivudine treatment for HBV in pregnancy, if the pt has had a previous perinatal transmission?

Answer 31

28 weeks | HBV DNA >/= 200,000 IU/mL or >10^6 copies/mL

Question 32

When should you start lamivudine treatment for HBV in pregnancy, if the pt has NOT had a previous perinatal transmission?

Answer 32

28 weeks | HBV DNA >/= 2,000,000 IU/mL or >10^7 copies/mL

Question 33

In clinical trials, effect of lamivudine prophylaxis on perinatal HBV transmission with lamivudine prophylaxis decreases by?

Answer 33

The overall effect favored lamivudine prophylaxis when these studies were combined (RR 0.31, 95% CI 0.15-0.63).