The U.S. Preventive Services Task Force (USPSTF) now recommends the hepatitis C virus (HCV) infection screening for adults in the age group 18 to 79 years. This update comes against the background of increasing HCV over the last ten years, primarily due to higher injection drug use, and closer monitoring. The recommendation ensures that this screening will be covered by insurance as well without cost-sharing.
HCV – the problem
About 2.4 million people in the U.S. have HCV infection, and over 4 million have or have had it at some point. Acute HCV infection has increased almost fourfold over the last ten years, primarily due to better detection and injectable opioid drug use by young adults.
HCV causes more deaths than all the rest of the 60 leading infectious diseases together, including tuberculosis and HIV. This virus infects the liver and causes significant damage. It is primarily transmitted by infected blood through the sharing of needles for injection drug use. Sexual transmission is possible but rare.
Symptoms of HCV are mild at first infection, but the virus establishes itself in the majority of individuals, causing chronic HCV, found in about 1% of Americans. Over several years or decades, the liver is destroyed and replaced by fibrous tissue. Liver failure and cirrhosis are potential outcomes, and the only treatment is a liver transplant. Liver cancer and death are the usual terminations in other patients.
Hepatitis Virus Cell in detailed view. Image Credit: decade3d - anatomy online / Shutterstock
Screening for HCV
Formerly, the decision to screen for HCV was based on the investigation of several risk factors such as a past history of injection drug use (“risk-based screening”). The efficiency of detection was about 80%, and about 12% of patients were being screened using these criteria. The treatment was built around the combination of injectable pegylated interferon alfa with oral ribavirin, but with a less than 1 in 2 chance of cure for the most common type of virus, the type 1 HCV. The use of interferons led to flu-like symptoms and lasted for 48 weeks, which made patients less compliant with the regimen.
The high prevalence of HCV in the population born from 1945 through 1965, which accounted for 3 of every 4 HCV-positive individuals, caused the Centers for Disease Control and Prevention (CDC) to recommend a one-time screening for this group, which led to the USPSTF recommendation to this effect in 2013, along with the older risk-based screening. The diagnostic yield was similar, at 75%.
However, in 2013, the U.S. Food and Drug Administration (FDA) approved two highly effective direct-acting antiviral (DAA) drugs that could achieve a cure. These need to be used for 12 weeks only. The current drugs efficiently achieve sustained virologic response or cure – the virus is not detectable in the serum at 12 weeks or more after a course of treatment – in 99% of cases.
Moreover, these drugs change the course of the disease, averting the risk of liver cirrhosis, liver cancer, and liver-related death in about 60%, 70%, and 90% of patients, respectively. The adverse effects of these drugs are relatively less than with older interferon-based regimens.
The drugs were extremely costly when introduced, but competition has driven down the prices till now, a cure for HCV costs less than a year’s worth of medication to control HIV.
The second reason to recommend universal screening is the opioid epidemic raging in the U.S. in people born after 1965, which is causing thousands of new HCV cases among adults 20-39 years old who have used injection drugs. Adolescents can be treated with these drugs. These drugs have not been extensively tested in adolescence and pregnant women.
Screening is also indicated for all pregnant women because many women aged 15-44 years are increasingly testing HCV positive, and the babies are born infected. While these women are not typically treated during pregnancy due to lack of clinical evidence, they are treated postpartum and the baby is also monitored for any signs of infection. HCV transmission is more likely if the membranes were ruptured for over 6 hours, and if internal fetal monitoring is used. Early detection ensures treatment before any risk of significant liver damage occurs in the baby.
Some scientists want to extend the program to provide free sterile needles and other harm reduction measures – encouraging and facilitating injectable drug use with one hand even while trying to control the infection introduced by it with the other! Their professed aim is to meet the World Health Organization (WHO) HCV eradication targets.
The blood test used to screen for HCV looks for the anti-HCV antibody, and if positive, the level of the virus is evaluated in the blood by HCV-RNA. The reason for screening with this test is to pick up HCV at the asymptomatic stage when it can be cured without significant liver damage, because
The screening is done only once if there are no symptoms. However, those at continuing risk, such as those who are using drugs actively, must be screened regularly. Again, those who have a higher risk, such as those who were using injection drugs in the recent past or are currently on them, should be screened, at any age.
From moving to non-risk-related screening for HCV, the USPSTF has now moved to make recommendations for screening of all adults, 18-79 years, without risk assessment, and of adolescents after risk assessment, and of pregnant adolescents. These cases should be linked to care to ensure they are treated for a cure. While there is no direct evidence that DAAs affect clinical outcomes following HCV infection, they do produce SVR over 95% and have few adverse effects. Meanwhile, an SVR achieved with antiviral therapy is associated with better clinical outcomes than in patients with no SVR.
- Jin, J., Screening for hepatitis C virus infection. JAMA patient page, March 2, 2020. doi:10.1001/jama.2020.1761
- Graham, C. S. and Trooskin, S. Universal screening for hepatitis C virus infection: a step toward elimination. JAMA March 2, 2020. doi:10.1001/jama.2019.22313
- Chou, R., Dana, T., Fu, R., Zakher, B., Wagner, J., Ramirez, S., Grusing, S., and Jou, J. H. Screening for Hepatitis C Virus Infection in adolescents and adults: updated evidence report and systematic review for the U.S. Preventive Services Task Force. JAMA March 2, 2020. doi:10.1001/jama.2019.20788
- USPSTF. Screening for Hepatitis C Virus Infection in adolescents and adults: U.S. Preventive Services Task Force recommendation statement. JAMA March 2, 2020. doi:10.1001/jama.2020.1123