Vertical transmission of the hepatitis C virus: Current knowledge and issues

Question 1

What percentage of adult Canadians have HCV?

Answer 1

1-3%

Question 2

Which populations are at higher risk of HCV infection?

Answer 2

1. Inuit
2. First Nations
3. Hemophiliacs who received untreated FVIII concentrates
4. IVDU
5. Sexual contact minor cause

Question 3

What are the major risk factors for pregnant women to have hepatitis C seropositivity?

Answer 3

1. Previous or current IVDU
2. Sexual partner of IVDU
3. Blood transfusion before 1990

Question 4

How do you interpret a child <2mo born to an HCV infected mother with HCV Ab +ve and HCV RNA PCR -ve?

Answer 4

Too early to interpret result as may not be viremic yet

Question 5

How do you interpret a child 2-17mo born to an HCV infected mother with HCV Ab +ve and HCV RNA PCR -ve?

Answer 5

Vertical transmission of HCV did not occur, or the child has cleared HCV

Test HCV Ab @ 18mo and if still present repeat HCV RNA PCR to ensure clearance

Question 6

How do you interpret a child >6mo born to an HCV infected mother with HCV Ab +ve and HCV RNA PCR +ve for >6mo?

Answer 6

Chronic HCV
Usu. persists indefinitely in absence of antiviral therapy, but spontaneous clearance likely more common in children than in adults

Question 7

How do you interpret a child >18mo born to an HCV infected mother with HCV Ab +ve and HCV RNA PCR -ve?

Answer 7

Clearance of HCV

Occurs spontaneously ~25% of acute HCV and small amt of chronic HCV

Question 8

How do you interpret a child of any age born to an HCV infected mother with HCV Ab -ve?

Answer 8

No need to test HCV RNA PCR. Vertical transmission did not occur or clearance

Question 9

How do you interpret a child of any age with detectable HCV RNA PCR <6mo or <6mo after a negative Ab or PCR test?

Answer 9

Acute HCV
75% develop chronic HCV
25% clear HCV

Question 10

How do you interpret a child of any age with absent HCV Ab and RNA PCR and HCV RNA present in liver or PBMCs?

Answer 10

Occult HCV

No pediatric studies

Question 11

How do you interpret a child of any age with absent HCV Ab and HCV RNA PCR present?

Answer 11

Seronegative (immunosilent) HCV, or very early acute HCV (infection typically occurred 20 to 60 days prior)
Seronegative HCV mainly described in HIV coinfected adults and other immunosuppressed patients with the incidence in children not known.

Question 12

What is the vertical transmission rate of HCV?

Answer 12

5%

If mother HCV RNA negative lower

Question 13

What are risk factors for vertical transmission of HCV?

Answer 13

1. Higher maternal viral titre
2. Elevated ALT level in year before pregnancy
3. Maternal cirrhosis
4. ?IVDU
5. HIV coinfection

Question 14

What should all women with HCV infection be screened for?

Answer 14

HIC

Chronic HBV infection

Question 15

What is the role of mode of delivery and breast milk in HCV transmission?

Answer 15

1. Insufficient evidence so mode of delivery should not be determined by maternal HCV status
2. Avoid scalp electrodes and amniocentesis
3. Breastfeeding is allowed unless maternal jaundice postpartum or cracked and bleeding nipples

Question 16

Should all pregnant women be routinely screened for HCV infection?

Answer 16

No, as no method to prevent vertical transmission and no known benefits to early detection

Question 17

Which groups of women are high risk and should get HCV screening?

Answer 17

Past or present IVDUs;
1. Recipients of blood products before 1990 in developed countries and/or at any time in developing countries;

2. Patients with unexplained elevated aminotransferase levels; and
3. Patients who have undergone organ or tissue transplantation from unscreened donors.

Question 18

What is the role of antiviral therapy for pregnant HCV-infected women or infected women contemplating pregnancy?

Answer 18

Treatment before pregnancy might be considered in women who are currently not IVDUs and who agree to use effective birth control until they complete antiviral therapy. The efficacy of antivirals administered during pregnancy or to the infant for prevention of vertical transmission has not been studied. Ribavirin is teratogenic in animals, and its safety in newborns has not been evaluated.

Question 19

What is the proper management of a child born to an infected mother?

Answer 19

1. No special precautions are required for newborn care
2. HCV serology @ 12 and 18mo
3. If significant parental anxiety to HCV RNA test @2mo
4. If 2mo HCV RNA positive req. HCV RNA and aminotransferase levels q6m
5. If 2mo HCV RNA negative do serology @ 12-18mo
6. Refer chronic HCV infection to peds GI, hepatologist or ID
7. HepB vaccine in 1st month of life
8. Hepatitis A vaccine at 1yo
9. No restriction for for daycare or sports and do not need to notify school or supervisors of chronic HCV
10. Theoretical risk of transmission if blood loss during contact sports

Question 20

What are the CPS recommendations?

Answer 20

1. Approximately 5% of pregnant women with chronic HCV infection will transmit the virus to their infants.
2. Currently, there are no specific interventions known to decrease perinatal transmission.
3. The primary diagnostic test for exposed infants is HCV serology performed at 12 to 18 months of age. HCV RNA performed after two months of age is a sensitive and specific, but expensive, test. Use should be considered if there is significant parental anxiety or if there is concern that the infant will be lost to follow-up.
4. Approximately 25% of infected infants will clear the virus spontaneously. The other 75% generally have only mild hepatitis throughout childhood, but they require follow-up because a small percentage will develop progressive liver disease and are at risk for hepatocellular carcinoma.