Monitoring Infants for Hepatitis C Virus

Research published in Open Forum Infectious Diseases addressed a lack of consistent strategies to clinically manage infants born to mothers with chronic hepatitis C virus infection (HCV). The authors analyzed data from one pediatric infectious disease center looking for clinical evidence that may suggest a useful age at which infants should be tested for vertical transmission of HCV.

The report said that 7000 new cases of prenatally acquired HCV are likely to occur in the United States, with 3% of those developing significant liver pathology. This poses a public health concern that could become costly without established best practices for screening and monitoring.

Managing the risk of HCV and liver disease among infants born to mothers with chronic HCV is a challenge that lacks clear evidence or guidelines, the report said. Four professional authorities on this subject all give different recommendations.

The American Academy of Pediatrics recommends testing infants for HCV antibodies (the anti-HCV test) after 12 months of age provided the infected mother is not routinely tested for HCV ribonucleic acid (RNA). The National Institutes of Health suggests testing infants for HCV RNA between the ages of 2 to 6 months and giving the anti-HCV test after the age of 15 months.

The European Society and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition recommends the anti-HCV test at 18 months old. The Centers for Disease Control and Prevention endorses HCV testing before the age of 18 months, including an initial HCV RNA test after 1 to 2 months of age and continued monitoring for HCV viremia regardless of initial result.

The decision on when to test an infant for HCV is further complicated by the fact that no approved medications for infant therapy currently exist.

Clinical Data Collection and Analysis

A study analyzed demographic and clinical data for 142 mother-infant pairs. Infants were born between 1998 and 2013 to mothers with chronic HCV.

Results of initial infant tests for HCV antibodies and HCV RNA were assessed by c² test to determine any patterns related to infant age.

Multiple regression models looked for any links between the number of tests administered before the age of 18 months, age at initial test, and results of initial test. Multiple regression also evaluated factors associated with infant age when antibody clearance was first detected.

Correlation analysis looked for any relationship between the infant’s year of birth and age of testing initiation.

Findings on the Clinical Screening of Infants at Risk of HCV

Among the 142 studied mother-infant pairs, 93.7% of mothers were intravenous drug users (IVDUs), 2.1% were HIV positive, and 77.5% had delivered vaginally.

Most of the infants had a gestational age of at least 35 weeks (96.5%) and were formula fed (90.8%).

Among 142 infants observed in their first 18 months of life, 3.5% were diagnosed with HCV infection, 1.4% had intermittent viremia, 66.9% had at least 1 positive result of anti-HCV antibody and negative HCV RNA, and 28.2% had negative anti-HCV antibody and HCV RNA.

HIV-HCV coinfection was present in the mother of 1 infant diagnosed with HCV.

“Initiation of HCV testing after 10 months of age was associated with a significant decline in the probability of obtaining a positive HCV antibody of maternal origin,” the study authors wrote.

Average infant age at first recorded HCV antibody clearance was 14.0 ± 2.7 months. Clearance of antibody was detected in 27.4% of infants before the age of 12 months and in 48.5% of infants between 12 and 16 months of age. Age at HCV antibody clearance was indirectly associated with the number of tests performed, but independent of the age at initiation of anti-HCV test.

Age at initiation of testing for HCV antibody and HCV RNA significantly correlated with the infant’s year of birth, suggesting that differing literature of the time influenced clinical decisions. About 50% of infants were tested within the first 4 months of life.

Regardless of the time of testing initiation, only a few initial HCV RNA tests were positive in the first 18 months of life.

Conclusion

Authors found their observations to be consistent with other research and concluded that postponing testing for anti-HCV antibody and HCV RNA up to 18 months of age is a reasonable approach in the management of infants born to mothers with HCV.

Even though they said it would be unlikely to detect and confirm true HCV transmission before 10 months of age, they acknowledged that early testing might assuage parental concerns and facilitate parental counseling, education, and consideration of treatment options.