SILVER SPRING, MD — New cases of acute and chronic hepatitis C (HCV) have dropped sharply among U.S. servicemembers since 2008, bucking the nationwide trend.

For the general population, the national Centers for Disease Control and Prevention (CDC) estimates that the incidence of acute HCV infection has more than tripled in the past decade, largely as a result of the opioid epidemic.

The crude annual incidence rate dropped from 17.6 diagnoses per 100,000 servicemembers in 2008 to 7.5 diagnoses per 100,000 in 2016, according to a study published in Medical Surveillance Monthly Report.1

The drop is particularly notable, given an increase in screening for hepatitis C as a result of a CDC recommendation to perform one-time screening for all patients born between 1945 and 1965. Individuals born in that 20 year period—the “baby boom”—account for 75% of all HCV infections in the U.S.

The screening recommendation might explain some of the differences seen in the rate of conversion of acute hepatitis C to the chronic disease in Military Health System (MHS) data, compared to the national rates of 75% to 85% estimated by the CDC. Researchers led by Shauna Stahlman, PhD, MPH, of the Armed Forces Health Surveillance Branch, found that 92% of servicemembers diagnosed with acute hepatitis C received a diagnosis of chronic hepatitis C in a median of 23 days.

The researchers posited that the CDC recommendation for screening of all baby boomers may have increased identification of chronic hepatitis C cases in the MHS. Stahlman and colleagues determined that active duty members of the Armed Forces born before 1965 had 4.5 times the rate of chronic hepatitis C seen in younger cohorts, 49.8 per 100,000, compared to 11.3 per 100,000 in those born between 1965 and 1980 and 11.2 per 100,000 in those born after 1980.

In addition, they suggested that the high rate could be attributed in part to initial misclassification, as HCV screening assays do not distinguish between acute, chronic and resolved infections. Acute HCV infection frequently has no symptoms, and many individuals may unknowingly have HCV for decades. Follow-up evaluations would lead to reclassification of some acute cases as actually chronic.

Scheduling of additional testing to clarify infection type in recent years “may also suggest enhanced attention to follow-up of newly diagnosed cases in the MHS, perhaps in an effort to link patients with new U.S. Food and Drug Administration approved medications indicated for treatment of chronic HCV genotype-specific infections,” the researchers noted.

The Defense Health Agency added all HCV direct-acting antivirals to the military treatment facility formulary in 2015. Those are approved for use in accordance with their FDA-approved indications or as recommended in the current guidelines issued by the American Association for the Study of Liver Diseases and the Infectious Diseases Society of America.

In 2017, the Defense Health Agency Pharmacy and Therapeutics Committee recommended making sofosbuvir/ledipasvir step-preferred and all other HCV direct-acting antiviral medications as nonstep-preferred but still formulary. Those include daclatasvir, grazoprevir/elbasvir, paritapreir/ritonavir/ombitasvir/dasabuvir (regular and ER), paritaprevir/ritonavir/ombitasvir, simeprevir, sofosbuvir, and sofosbuvir/velpatasvir.

All therapies require manual prior authorization. Generally, the drugs achieve sustained viral response in more than 94% of patients within 12 weeks.

With a cure possible, screening for HCV infection has the potential to significantly improve long-term health in affected individuals, as HCV significantly increases the risk of hepatocellular carcinoma and other liver disease. Despite the benefit, initial response with the MHS to the CDC’s recommendation to screen the highest risk population has been slow.

Marginal Screening Increase

In the first year after the August 2012 CDC recommendation to screen all baby boomers for hepatitis C, the MHS reported only a marginal increase in screening. A study published in Public Health Reports that drew on the MHS medical claims database compared screening rates from July 2011 to July 2012 to those between September 2012 and September 2013. It found that, of 108,233 individuals born between 1945 and 1965, 1,812 (1.7%) received screening in the year before the CDC recommendation. In the year after the recommendation, 109,768 baby boomers were eligible for screening, and 2,599 (2.4%) were screened for HCV.2

Individuals with TRICARE Prime had three times the screening rate of those with other TRICARE coverage or unknown benefit types in both periods and their rate rose from 2.5% before the CDC recommendation vs. 3.5% after it. All active-duty servicemembers must use TRICARE Prime.

“A systemwide policy and increased awareness by providers and the baby boom population may be most effective for increasing HCV screening rates in the MHS,” explained Janna Manjelievskaia, PhD, MPH, lead author of the screening study and senior research analyst at Truven Health Analytics in Bethesda, MD. Manjelievskaia was formerly a health services researcher at the Henry M. Jackson Foundation for the Advancement of Military Medicine.

Both providers and patients might have attitudes that reduce the rate of screening, she noted. “The main barriers to screening are competing priorities in the baby boomer population (other co-morbid conditions), lack of perceived importance of HCV screening in this population among providers and a lack of awareness among baby boomers,” she told U.S. Medicine.

Screening rates also might appear lower than they are because some individuals who receive care through the Military Health System also have other non-DoD health insurance, such as Medicare or coverage through a spouse, she said. The study authors also noted that the CDC recommendations had just come out during the period studied, and adoption of screening recommendations often takes a few years in any health system.

Until recently, the elevated rates of HCV infection among individuals born between 1945 and 1965 had been attributed to high-risk behaviors such as injection drug use, high-risk sex, unsafe tattooing and, particularly among those who served in the military, travel to areas with high endemic rates of HCV. Those explanations have contributed to a stigma in connection to hepatitis C that a study published in The Lancet Infectious Diseases said is unwarranted. The study determined through phylogenetic analysis that the HCV epidemic likely began with battlefield blood transfusions during World War II and spread through the use of glass and metal syringes in hospitals through the 1950s.3

The Lancet study brings the importance of screening in military recruits and servicemembers full circle. HCV’s spread among individuals now in their late 50s to early 70s might have started on the battlefields of Europe and Asia, but, for the young men and women fighting today, Stahlman and her colleagues noted it remains “an important public health concern, because emergency battlefield blood supply and operation capabilities may be compromised.”

1Stahlman S, Williams VF, Hunt DJ, Kwon PO. Viral hepatitis C, active component, U.S. military service members and beneficiaries, 2008-2016. MSMR. 2017 May;24(5):12-17.

2Joy JB, McCloskey RM, Nguyen T, Liang RH, Khudyakov Y, Olmstead A, Krajden M,Ward JW, Harrigan PR, Montaner JSG, Poon AFY. The spread of hepatitis C virus genotype 1a in North America: a retrospective phylogenetic study. Lancet Infect Dis. 2016 Jun;16(6):698-702.

3Manjelievskaia J, Brown D, Shriver CD, Zhu K. CDC Screening Recommendation for Baby Boomers and Hepatitis C Virus Testing in the US Military Health System. Public Health Rep. 2017 Sep/Oct;132(5):579-584. doi: 10.1177/0033354917719446.Epub 2017 Aug 2.