CDC's Count of Acute Hepatitis C Is Tip of the Iceberg, Say Researchers
August 6, 2015
The number of Americans infected with acute hepatitis C (HCV) is vastly underreported to the U.S. Centers for Disease Control and Prevention (CDC), according to a case study from Massachusetts General Hospital, and funded by the National Institutes of Health.
The CDC gleans its nationwide estimate from local public health officials, who report the number of confirmed cases in their respective regions. In 2010, for example, local health authorities across the country reported a total of 850 acute HCV cases to the CDC. Therefore, the CDC estimated that 17,000 cases occur annually in the U.S.
Yet, the case study suggests those figures are dramatically low. The paper, which was published in the Annals of Internal Medicine, didn't pull any punches. In their conclusion, the authors wrote, "Clinical diagnoses of acute HCV infection were grossly underascertained by formal surveillance reporting."
Senior author Arthur Kim, M.D., of the Massachusetts General Hospital Division of Infectious Diseases, likened the instance of HCV to an iceberg, of which only the tip is visible, according to a press release.
Kim and the other authors drew their conclusions after conducting the 10-year case study in Massachusetts. The team followed 183 research participants diagnosed with acute HCV from 2001 to 2011. Of those cases, they were trying to determine how many were actually reported to the CDC.
They found that only 149 cases were reported to the Massachusetts Department of Public Health (DPH), and entered into the database. What's more, due to limiting "case definitions" allowed by the Massachusetts DPH, 130 cases were defined as "past or present HCV," and 43 were defined as "potential acute HCV."
Moreover, because of the intricacies of the reporting and classification system, only one case actually met CDC reporting criteria for a confirmed case of acute HCV. All other patients were disqualified from the final count because of a myriad of complex criteria.
For example, some patients were lacking certain symptoms, or their lab tests didn't meet certain thresholds. Sometimes, lab tests went missing at the Massachusetts DPH, or patients were disqualified if they had never been screened negative for hepatitis A and B.
The authors point out that Massachusetts features one of the best health systems in the country, so reporting might be even worse in other states. (However, the paper offers a disclaimer that the finding might not apply to other jurisdictions because of variation in resources.)
The Massachusetts example demonstrated that only a fraction of the actual HCV cases reported to local authorities are counted in the nationwide statistics reported by the CDC. According to Kim and the other study authors, this example is a strong indicator that the CDC's national HCV estimates are low. Kim recommended that more resources be devoted to surveillance, according to the press release.
Even though the incidence of HCV has been declining since the 1990s, the boom in opioid use is likely leading to an increase in the number of infections. With the burden of disease shifting to new communities, it is even more crucial to have accurate reporting of infection rates -- both at a national and regional level.
The Massachusetts DPH already changed some of its reporting procedures in response to this study, Kim points out in the press release. In addition, an organization called the Council of State and Territorial Epidemiologists changed its case definitions for "active" and "chronic" HCV infections -- those changes will be adopted by the CDC in January 2016.
This article was provided by TheBody.com.
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