A new study published in the BMJ on 22nd March found that the current US Centers for Disease Control (CDC) guidelines on hepatitis C virus testing would not be able to diagnose 1 in 4 infected individuals. One-time testing for all adults over 18 years of age from high risk urban populations will not be very effective in hepatitis C diagnosis. Current testing protocol will miss some individuals visiting an emergency department (ED) who are infected with the hepatitis C virus (HCV); only those with a chronic form of HCV will be diagnosed.

Currently about 2.7 to 3.9 million individuals i.e., 1.0% to 1.5% of the US population, are suffering from the chronic form of hepatitis C, which is a disease characterized by the inflammation of the liver. The HCV is a blood-borne virus transferred by sharing infected needles. In 75% to 85% of cases infected with HCV, the illness develops into a long-term chronic affliction which can even result in death. Hepatitis C has no vaccine or cure and the only way to prevent infection is avoiding infected needles. In 2013, an estimated 29,718 new cases of acute HCV infections were reported and the prevalence is expected to have risen in the US.

Yu-Hsiang Hsieh was the lead author of the study, from Johns Hopkins School of Medicine’s Department of Emergency Medicine in Baltimore. Hsieh and co-workers carried out a Sero-prevalence i.e., the level of a pathogen in a population as measured in blood serum, study at the Johns Hopkins Hospital ED in 2013. They tested for HCV antibodies in the excess blood serum samples taken from 4,713 adult patients, taken over a period of eight weeks. The demographic and clinical data such as documented HCV infection were also obtained from the electronic medical records.

The CDC has recommended testing for HCV at least once for individuals born between 1945 and 1965 and especially those with a history of injected drug use, since these populations have higher risk of contracting infection. The testing criteria set by the CDC for HCV is also known as the birth cohort testing. However, due to practical reasons and hectic schedules many emergency departments only use taking history and filling questionnaires on HIV status and drug use using needles, as a risk based screening tool.

“Hepatitis C virus (HCV) is an increasing cause of morbidity and mortality in the United States,” said Dr John Ward MD, the Director of the Division of Viral Hepatitis at National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention (NCHHSTP), CDC. “CDC is augmenting previous recommendations for HCV testing to recommend one-time testing without prior ascertainment of HCV risk for persons born during 1945-1965, a population with a disproportionately high prevalence of HCV infection and related disease. Persons identified as having HCV infection should receive a brief screening for alcohol use and intervention as clinically indicated, followed by referral to appropriate care for HCV infection and related conditions. These recommendations will be reviewed every five years and updated to include advances in the published evidence.”

The results of the serum testing found about 652 (13.8%) of the patients tested positive for HCV sero-prevalence, meaning they were either actively infected or had been in the past. Out of the 652 patients, about 204 (31.3%) were not documented as having HCV in their medical records, meaning previously they had remained undiagnosed. The study also concluded out of the 204 undocumented HCV cases, about 99 individuals i.e., 48.5% could have been identified for HCV through birth cohort testing. Another 54 undocumented individuals i.e., 25% with undocumented HCV may have been identified on the basis of risk based testing. However, 51 patients with HCV i.e., the rest of the 25% of the study group from the undocumented cases would not have been identified at all.

The study concluded that on the basis of estimates, if we suppose there are 7,727 unique cases of HCV infection every year, then the current CDC, birth cohort plus risk-based testing guidelines would be able to identify 1,815 undocumented infections. However, a total of 526 patients with chronic HCV may remain undiagnosed in the US every year due to the current CDC testing program and the frantic situation of in hospitals.

The CDC testing criteria for HCV has been formulated for the general population but is not compatible with diagnosis of infected populations in urban ED, especially adult populations, in which the HCV sero-prevalence is high the current testing is not very effective. So a new HCV management and testing system along with new treatment resources are needed in the US emergency departments. The new ED-based HCV testing would also ensure more than 6,700 patients with chronic hepatitis C would be diagnosed per year.

“Birth cohort-based testing would augment identification of undocumented HCV infections in this ED twofold, relative to risk-based testing only,” said Yu-Hsiang Hsieh. “However, our data demonstrates that one-quarter of infections would remain undiagnosed if current CDC birth cohort recommendations were employed, suggesting that in high-risk urban ED settings a practice of universal one-time testing might be more effective.”

It was concluded that routine usage of the birth cohort testing may increase HCV diagnosis by twofold in emergency departments, but it will still not be able to diagnose 25% of the cases with HCV and a new testing system is required for them.