Hepatitis C: The Problem with Numbers, by Alan Franciscus, Editor-in-Chief

Originally Published July 15, 2015

A recently released journal article estimated that the real number of acute hepatitis C cases are much higher than the figures published by the Centers for Disease Control and Prevention (CDC).  This is not a revelation to those who work in HCV.  In this article, I will discuss the published numbers of acute and chronic HCV and what some experts believe is a better estimate of the number of acute, chronic and annual deaths caused by hepatitis C.

Acute
The CDC estimated that there were 29,700 acute cases of HCV in 2013 (range 23,500 to 101,400).  In the article, “Underascertainment of Acute Hepatitis C Virus Infections in the U.S. Surveillance System: A Case Series and Chart Review,” by S Onofrey, MPH et. al., published in the Annals of Internal Medicine, the authors challenged the way the CDC defined an acute case and compared the actual diagnosed cases to the number of diagnosed cases that fit the CDC definition. 

Note:  There are many problems with diagnosing acute HCV—there are no viral markers to distinguish acute vs. chronic.  Another issue is that most people acutely infected have no symptoms.

The current study took place in Massachusetts from 2001 to 2011.  There were 183 patients diagnosed with acute HCV, but only 149 cases were reported to the Massachusetts Department of Public Health.  Of these, 130 were classified as potential acute infection.  But only ONE met the national case definition that was reported to the CDC.  

This means that only 1% of acute HCV cases were ever reported to the CDC.  We know that there have been outbreaks of acute HCV around the country including recent outbreaks in regions in or near the Appalachia area. 

Chronic Hepatitis C
The CDC estimated that in 2013 there were 2.7 to 3.9 million people who were chronically infected with hepatitis C.  However, the NHANES survey doses not count certain populations such as prisoners, homeless, nursing home residents, people in mental institutions, nor active duty military—many of these populations have a very high incidence of hepatitis C.  If the populations that were excluded from the NHANES survey were to be included the number of people with chronic hepatitis C could reach 5 million Americans. 

Also if you include the surge of the new acute infections that would turn chronic this would also increase the total chronic infections.  It is all connected. 

HCV Deaths
The CDC estimated that there were 19,368 deaths caused by HCV in 2013.  There was also a footnote that read “Current information indicates these represent a fraction of deaths attributable in whole or in part to chronic hepatitis C.” 

Another article, “Mortality among Persons in Care with Hepatitis C Virus Infection—The Chronic Hepatitis Cohort Study (CHeCS), 2006–2010,” by R Mahajan and colleagues, was published in Clin Infect Disease 2014 Jun; 59(12)1792.  The study estimated the number of deaths caused by hepatitis C

In the study, 2,143,369 patients (MCOD group—all patients) seen between 2006 – 2010 at the CHeCS clinics were included in the analysis.  There were 11,703 (0.5%) HCV patients.  A total of 1,590 (14%) died and had HCV listed as the cause of death.  The majority were born between 1945 and 1965 (75%), white (50%), and male (68%).  The mean age was 59 yo. 

To illustrate why HCV is under reported on death certificates the following was mentioned in the study:

“Among the 1590 CHeCS members who died, only 306 (19%) had HCV infection listed as an underlying cause on their death certificate. Among people who died of liver cancer, only 32% had HCV listed as an underlying cause. Death certificates did not list HCV for most deaths regardless of whether the deaths were liver-related or not. Among CHeCS members who died, medical records (ICD-9 codes) noted liver disease in 63%, and FIB-4 scores indicated liver disease in 76%.”