HCV Screening: Focus on Special Populations

According to Centers for Disease Control and Prevention (CDC), the incidence of hepatitis C virus (HCV) infections in the United States has almost tripled from 2011 to 2015. While the number of cases reported to the agency in 2015 was just under 2500, CDC estimates that approximately 34,000 new HCV infections actually occurred that year.¹ This increase is largely thought to be secondary to the rising rates of injection drug use, especially among persons aged < 30 years. Young women and men who inject drugs are equally at risk of contracting HCV.

[[{"type":"media","view_mode":"media_crop","fid":"60185","attributes":{"alt":"","class":"media-image media-image-right","id":"media_crop_3894244321497","media_crop_h":"0","media_crop_image_style":"-1","media_crop_instance":"7576","media_crop_rotate":"0","media_crop_scale_h":"0","media_crop_scale_w":"0","media_crop_w":"0","media_crop_x":"0","media_crop_y":"0","style":"height: 222px; width: 300px; float: right;","title":" ","typeof":"foaf:Image"}}]]A subset of the young population that is of interest is pregnant women with HCV. Mother-to-child transmission (MTCT) is thought to be the most common cause of new infections in children in the developed world. The risk of HCV from MTCT is thought to be low with a rate of 3 to 5%. Unfortunately there was a 68% increase nationally in children born to HCV infected mothers from 2011 to 2014 with a 22% increase in HCV detection in women of childbearing age.² As with the overall increase in rates of HCV, this rise is also attributed to the escalation in injection drug use and particularly associated with the current US opioid epidemic. The CDC stresses the importance of HCV testing among women of childbearing age, particularly those with a history of injection drug use, followed by linkage to appropriate care, and treatment. Also infants who are born to mothers with HCV should be tested for HCV and monitored closely as per CDC guidelines.²

The potential teratogenic effects of ribavirin and interferon prohibit HCV treatment during pregnancy. Newer agents, ie the direct acting antivirals, have not been approved for use in pregnancy or during breastfeeding. Women should be evaluated for HCV treatment after the appropriate postpartum period.²

Another population subset to consider for HCV screening is persons who may have contracted HCV through sexual exposure.  Although very low, risk of contracting HCV with sexual activity should be considered. According to CDC, 15 to 20% of patients with acute HCV (estimated duration of infection < 6 months) have contracted the infection via sexual exposure. Having multiple sexual partners is a risk factor for acute HCV and the risk is higher in men who have sex with men.^3,4

The CDC has mandated HCV testing of high risk populations such as injection drug users, “baby boomers” (adults born between 1945 and 1965), and those with HIV infection.⁵ Of equal importance for screening are other high risk populations such as women of childbearing age, pregnant females, those who have sexual encounters with HCV-positive persons, and men who have sex with men. Every patient encounter is an opportunity to identify a member of a population at high risk of contracting or transmitting the infection; screening and follow up tests should be offered.

References:

1. CDC. Summary of Trends in Viral Hepatitis – United States, 2015

https://www.cdc.gov/hepatitis/statistics/2015surveillance/commentary.htm

2. Increased Hepatitis C Virus (HCV) Detection in Women of Childbearing Age and Potential Risk for Vertical Transmission - United States and Kentucky, 2011–2014. MMWR. 2016;65;705–710 https://www.cdc.gov/mmwr/volumes/65/wr/mm6528a2.htm?s_cid=mm6528a2_e

3. Sexual Transmission and Viral Hepatitis Key Facts about Sexually Active Adults and Viral Hepatitis.

https://www.cdc.gov/hepatitis/populations/stds.htm

4. CDC. 2015 Sexually Transmitted Diseases Treatment Guidelines.

https://www.cdc.gov/std/tg2015/default.htm

5. CDC Testing Recommendations for Hepatitis C Virus Infection. https://www.cdc.gov/hepatitis/hcv/guidelinesc.htm