The opioid epidemic currently plaguing the country is being blamed for a dramatic increase in the number of pregnant women with hepatitis C.
An estimated 3.5 million Americans live with hepatitis C, making it the country's.
A new report released Thursday finds that hep C infections among pregnant women nearly doubled from 2009 to 2014. Rural areas of states including Tennessee and– the same areas hit hardest by the opioid epidemic – were disproportionately affected.
"If I overlayed a map of the United States and looked at rates ofafter birth, it would be very similar," lead author Stephen Patrick, M.D., an assistant professor of pediatrics and health policy at Vanderbilt University Medical Center, told CBS News. "We suspect this is highly linked to the opioid epidemic."
Injection drug use is the main risk factor for contracting the hepatitis C virus.
Overall, the number of new hepatitis C virus infections reported to the U.S. Centers for Disease Control and Prevention nearly tripled from 2010 to 2015, hitting a 15-year high. People with hep C often don't experience symptoms, and the CDC estimates that half of those infected don't know they have it. Left untreated, the infection can eventually cause severe liver disease and can be fatal.
The report found thatinfections in women at the time of childbirth increased 89 percent, from 1.8 to 3.4 instances per 1,000 live births from 2009 to 2014. This is equivalent to 35 infants exposed to the virus per day.
The study, which was done in conjunction with the Tennessee Department of Health, was published in the CDC's Morbidity and Mortality Weekly Report (MMWR).
The researchers noted substantial state-by-state variation, with rural states and Appalachian counties most affected. West Virginia had the highest infection rate in 2014 at 22.6 per 1,000 live births.
In Tennessee, where the rate of infection in 2014 was 10.1 per 1,000 live births, the chances of a hepatitis C infection at birth were approximately three times higher for women living in rural counties. In some counties in the state, nearly 8 percent of pregnant women were documented as being infected with hepatitis C at the time of delivery.
The researchers also found a higher risk for hepatitis C for women whoand for those who were also infected with hepatitis B.
The authors say the findings highlight the importance of ensuring that women of childbearing age have access to hepatitis C screening and treatment.
"Women need treatment and they can't get treatment during pregnancy," Patrick said. "One strategy to prevent transmission would be to screen and target women of reproductive age before they get pregnant and if they're infected to treat them before."
The authors also stressed the need for a system to ensure all infants exposed to hepatitis C are monitored to see if they get the virus and offer care.
Patrick said the findings have major implications for public health, particularly when it comes to how policymakers approach the opioid epidemic.
"Providers need to be aware of this increased risk of hepatitis C in pregnant women and so that they are testing for it, especially in high prevalence areas," he said. "More broadly, as we think about our response to the opioid epidemic, it's just another reason why we need to have a public health approach that focuses on primary prevention of opioid use before it even becomes a problem and expansion of treatment."
Tennessee Department of Health Epidemiologist Tim Jones, M.D., also notes that the study is an important reminder of the growing epidemic of hepatitis C in high-risk populations throughout the United States.
"While this study focuses on pregnant women and a high-risk area in Tennessee, it is also important to remember that hundreds of thousands of people throughout the U.S. have hepatitis C, and a large percentage of them do not know it," Jones said in a statement. "Anyone born between 1945-1965, or who has ever used IV drugs, or is otherwise worried about hepatitis infection, is encouraged to discuss with their clinicians whether testing may be appropriate for them."