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Hepatitis C Infection
Transmission
Hepatitis C virus (HCV) is a single-stranded RNA virus in the
Flaviviridae family.The average time to seroconversion after exposure to HCV is 8 to 9 weeks.
Acutely infected individuals may develop clinically apparent hepatitis with
loss of appetite, nausea, vomiting, fever, abdominal pain and jaundice.
60%-70% of patients with acute HCV infection are asymptomatic. [1]
Injecting-drug use currently accounts for 60% of HCV transmission in the
United States.Blood transfusion, is now an uncommon cause of recently acquired
infections [1]. Sexual transmission of HCV appears to be inefficient relative to
hepatitis B virus (HBV). Transmission between sexual partners of persons
with chronic HCV infection with no other risk factors for infection is about
5% (range, 0% to 15%) [1-4] Household contact with an infected person has been associated with a
nonsexual transmission rate of 4% (range, 0% to 11%) [2,5,6 ]. Approximately 7-8% of hepatitis C virus-positive women transmit hepatitis
C virus to their offspring with a higher rate of transmission seen in women coinfected with HIV [7] .
Sequelae
Acute HCV infection progresses to chronic HCV infection in most persons
(75%--85%). Cirrhosis develops in 10%-20% of persons with chronic hepatitis C and hepatocellualr carcinoma in 1%-5%.[1]. In one small study acute maternal hepatitis (type B or nontype B) had no
effect on the incidence of congenital malformations, stillbirths, abortions,
or intrauterine malnutrition. However, acute hepatitis did increase the
incidence of prematurity [8]. Pregnancy does not appear to be adversely affected by chronic HCV [9,10].
Who to Test [1]
“Persons who ever injected illegal drugs, including those who injected
once or a few times many years ago and do not consider themselves as drug
users.
Persons who received clotting factor concentrates produced before 1987;
Persons who were ever on chronic (long-term) hemodialysis; and
Persons with persistently abnormal alanine aminotransferase levels.
Prior recipients of transfusions or organ transplants, including
- Persons who were notified that they received blood from a donor who later
tested positive for HCV infection;
- Persons who received a transfusion of blood or blood components before
July 1992; and
- Persons who received an organ transplant before July 1992.
Healthcare, emergency medical, and public safety workers after needle
sticks, sharps, or mucosal exposures to HCV-positive blood.
Children born to HCV-positive women. “
Diagnosis
The diagnosis of HCV infection can be made by detecting either anti-HCV
by enzyme
immunoassay (EIA) or HCV RNA using the reverse transcriptase polymerase
chain
reaction (RT-PCR). If the HCV RNA result is negative supplemental testing
should be
performed. The CDC recommends confirmation of a positive EIA with supplemental
recombinant immunoblot assay (RIBA TM) or RT-PCR for HCV RNA. (Figure 1). Supplemenatal testing using RIBA
TM may be run on the same sample as the EIA.
However, If RT-PCR is used to confirm anti-HCV results, a separate serum
sample will
need to be collected.
The present supplemental RIBA TM detects four viral antigens. The test is
considered
positive if at least two antigens are detected. The test is indeterminate if
only one antigen
is detected. If the RIBA TMis indeterminate , further laboratory testing
might include
repeating the anti-HCV in two or more months or testing for HCV RNA and ALT
level.[11] Table1.[1] may be helpful at arriving at a proper diagnosis.
Table 1: Use of diagnostic tests in hepatitis C
| Category |
ELISA |
RIBA | HCV RNA |
ALT |
| Chronic hepatitis C |
Positive |
Positive | Positive |
Raised |
| Hepatitis C carrier |
Positive |
Positive |
Positive |
Normal |
|
Recovered HCV infection |
Positive |
Positive |
Negative |
Normal |
|
False positive anti-HCV |
Positive |
Negative |
Negative |
Normal |
ELISA=anti-HCV by enzyme-linked immunoassay;
RIBA=anti-HCV by recombinant immunoblot assay; ALT=alanine aminotransferase.
From Di Bisceglie AM. Hepatitis C Lancet 1998; 351: 351-55
Antepartum
Treatment
Persons with hepatitis C should be referred to health-care professionals with
experience in the treatment of hepatitis C.Current approved therapy for HCV-related chronic liver disease includes alpha
interferon alone or in combination with the oral agent ribavirin. Alpha-interferon-2b and ribavirin are the current treatment. Interferon does
not appear to have an adverse affect the embryo or fetus. However, the data is
limited, and the potential benefits of interferon use
during pregnancy should clearly outweigh possible hazards[12-14].Because there are no large studies of ribavirin use during human pregnancy,
and ribavirin is
teratogenic (causes birth defects) in multiple animal species the use of
ribavirin during pregnancy is presently contraindicated [15].
Pregnant patients with hepatitis C should be advised to
Obtain vaccination against hepatitis viruses A and B as indicated.
Abstain form alcohol use.
Avoid hepatotoxic drugs such as acetaminophen (Tylenol) that may worsen liver
damage.
Inform the infant’s pediatrician of the mother’s hepatitis C status.
Not donate blood, body organs, other tissue, or semen.
Not share any personal items that may have blood on them (e.g., toothbrushes
and razors).
Discuss the low but present risk for transmission with their partner and
discuss the need for counseling and testing. However, HCV-positive persons with
one long-term, steady sex partner do not need to change their sexual practices.
[1]
Liver enzymes and PCR should be obtained at the beginning of pregnancy, and
as needed thereafter [16]
The following recommendations from The Society of Obstetricians and
Gynecologists of Canada may be helpful in counseling women considering
amniocentesis.
SOGC Recommendations [17]
“Amniocentesis in women infected with hepatitis C does not appear to
significantly increase the risk of vertical transmission, but women should be
counseled that very few studies have properly addressed this possibility.
In HIV-positive women all noninvasive screening tools should be used prior to
considering amniocentesis.
For women infected with hepatitis B, hepatitis C, or HIV, the addition of
noninvasive methods of prenatal risk screening, such as nuchal translucency,
triple screening, and anatomic ultrasound, may help in reducing the age-related
risk to a level below the threshold for genetic amniocentesis.
For those women infected with hepatitis B, hepatitis C, or HIV who insist on
amniocentesis, every effort should be made to avoid inserting the needle through
the placenta. “
Delivery and Postpartum
The risk of vertical transmission of HCV appears to be related to the level
of viremia in the pregnant mother and not to the route of delivery. The virus
does not appear to be transmitted when a woman's titer is < 10^6/mL or is
negative [18-20]. Although Tejari et al [21] and Conte et al [22] did not find cesarean section
to be protective against transmission of HCV to the neonate Gibb et al have
found the HCV maternal to child (MTC) transmission rate to be reduced in patient
delivered by elective cesarean[23]. The latter study has yet to be confirmed.
Elective cesarean to reduce MCT transmission of HCV is not presently recommended
by the Centers for Disease Control, American Academy of Pediatrics or the
American College of Obstetricians and Gynecologists (ACOG)[1,7,24]. At delivery staff and the baby’s pediatrician should be notified of the
mother’s hepatitis C carrier state.Breastfeeding does not appreciably increase the risk of transmitting HCV to a
neonate [21, 24-26]
REFERENCES:
1. CDC Recommendations for Prevention and Control of Hepatitis C Virus (HCV)
Infection and HCV-Related Chronic Disease
MMWR October 16, 1998 / 47(RR19);1-39
2. Bjoro K, et al. Hepatitis C infection in patients with primary
hypogammaglobulinemia after treatment with contaminated immune globulin. N Engl
J Med. 1994;331:1607-1611 MEDLINE
3. Alter MJ, Hadler SC, Judson FN, et al: Risk factors for acute non-A, non-B
hepatitis in the United States and association with hepatitis C virus infection.
JAMA 264:2231-2235, 1990.MEDLINE
4. Alter MJ, Coleman PJ, Alexander WJ, et al: Importance of heterosexual
activity in the transmission of hepatitis B and non-A, non-B hepatitis. JAMA
262:1201-1205, 1989.MEDLINE
5. Dienstag JL: Sexual and perinatal transmission of hepatitis C. Hepatology
26:66S-70S, 1997.
MEDLINE
6. Meisel H, Reip A, Faltus B, et al. Transmission of hepatitis C virus to
children and husbands by women infected with contaminated anti-D immunoglobulin.
Lancet 1995;345:1209-1211 MEDLINE
7. ACOG educational bulletin. Viral hepatitis in pregnancy. Number 248, July
1998 . American College of Obstetricians and Gynecologists. Int J Gynaecol
Obstet. 1998;63:195-202.
MEDLINE
8. Hieber JP, Dalton D, Shorey J, Combes B.Hepatitis and pregnancy. J Pediatr.
1977;91:545-9.
MEDLINE
9. Floreani A, Paternoster D, Zappala F, Cusinato R, Bombi G, Grella P,
Chiaramonte M.Hepatitis C virus infection in pregnancy. Br J Obstet Gynaecol.
1996;103:325-9.
MEDLINE
10 Jabeen T, Cannon B, et al.. Pregnancy and pregnancy outcome in hepatitis C type 1b.QJM. 2000 Sep;93(9):597-601.
MEDLINE
11. Guidelines for Laboratory Testing and Result Reporting of Antibody to
Hepatitis C Virus* February 7, MMWR 2003 / 52(RR03);1-16
12. Ozaslan E, Yilmaz R, Simsek H, Tatar G. Interferon therapy for acute
hepatitis C during pregnancy. Ann Pharmacother. 2002;36:1715-8.MEDLINE
13. Hiratsuka M, Minakami H, Koshizuka S, Sato I. Administration of
interferon-alpha during pregnancy: effects on fetus. J Perinat Med.
2000;28:372-6. MEDLINE
14. Briggs GG,Freeman RK, Yaffe SJ, Drugs in Pregnancy and Lactation 5th
edition,Baltimore, MD:
Williams & Wilkins,1998 p 716-720.
15. Briggs GG,Freeman RK, Yaffe SJ, Drugs in Pregnancy and Lactation 5th
edition,Baltimore, MD:
Williams & Wilkins,1998 p 1219.
16. Paternoster DM, Santarossa C, Grella P, Palu G, Baldo V, Boccagni P,
Floreani A. Viral load in HCV RNA-positive pregnant women. Am J Gastroenterol.
2001;96:2751-4. MEDLINE
17. Davies G et al Society of Obstetricians and Gynaecologists of Canada.
Amniocentesis and women with hepatitis B, hepatitis C, or human immunodeficiency
virus. J Obstet Gynaecol Can. 2003;25:145-48, 149-52.MEDLINE
18. Ohto H, Terazawa et al.Transmission of hepatitis C virus from mothers to infants. The Vertical
Transmission of Hepatitis C Virus Collaborative Study Group. N Engl J Med.
1994;330:744-50.
MEDLINE
19. Ferrero S, Lungaro P, Bruzzone BM, Gotta C, Bentivoglio G, Ragni
N.Prospective study of mother-to-infant transmission of hepatitis C virus: a
10-year survey (1990-2000).Acta Obstet Gynecol Scand. 2003;82:229-34.MEDLINE
20. Thomas SL, Newell ML, Peckham CS, Ades AE, Hall AJ. A review of hepatitis C
virus (HCV) vertical transmission: risks of transmission to infants born to
mothers with and without HCV viraemia of human immunodeficiency virus infection.
Int J Epidemiol 1998; 27: 108-17. MEDLINE
21. Tajiri H, Miyoshi Y, Funada S, Etani Y, Abe J, Onodera T, Goto M, Funato M,
Ida S, Noda C, Nakayama M, Okada S. Prospective study of mother-to-infant
transmission of hepatitis C virus.Pediatr Infect Dis J. 2001;20:10-4.
MEDLINE
22. Conte D, Fraquelli M, Prati D, Colucci A, Minola E. Prevalence and clinical
course of chronic hepatitis C virus (HCV) infection and rate of HCV vertical
transmission in a cohort of 15,250 pregnant women.Hepatology. 2000;31:751-5.
MEDLINE
23. Gibb DM, Goodall RL, Dunn DT, et al Mother-to-child transmission of
hepatitis C virus: evidence for preventable peripartum transmission. Lancet.
2000 Sep 9;356(9233):904-7.
MEDLINE
24. Hepatitis C virus infection. American Academy of Pediatrics. Committee on
Infectious Diseases.
Pediatrics. 1998 ;101(3 Pt 1):481-5
MEDLINE
25. Hunt CM, Carson KL, Sharara AI. Hepatitis C in pregnancy. Obstet Gynecol.
1997;89:883-90.MEDLINE
26. ACOG Committee Opinion: Breastfeeding and the Risk of Hepatitis C Virus
Transmission, August 1999Int J Gynaecol Obstet. 1999;66:307-8.
MEDLINE
ADDITIONAL READING:
Vertical
transmission of the hepatitis C virus : current knowledge and issues
Canadian Medical Association
Hepatitis
Center for Disease Control and Prevention
Created: 12/10/2000
Last update: 11/30/2003
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