In a related analysis described in the May 15 edition of Clinical
Infectious Diseases, Kathleen Ly and colleagues from the Division
of Viral Hepatitis looked at trends in hepatitis C-related mortality in the US
compared to trends for 60 other nationally notifiable infections routinely
reported to the CDC.
The researchers used death certificate
information from the National Center for Health Statistics to analyse
multiple-cause-of-death data from 2003 to 2013. To calculate mortality
rates, the number of deaths associated with HCV infection and other notifiable
infections were divided by the total US census population for each year and
adjusted for the age distribution of the population.
From 2003 to 2013 the number of deaths
associated with hepatitis C rose from 11,051 to 19,368, for an average annual
increase of 865 deaths per year or +6.2%. The hepatitis C mortality rate
increased from 3.72 to 5.03 deaths per 100,000 persons. Just over half of these
deaths occurred among people age 55 to 64.
In contrast, the number of deaths associated
with 60 other notifiable infectious diseases fell from 24,745 in 2003 to 17,915
in 2013, an average annual decrease of 718 deaths per year or -3.4%. The
mortality rate for these other infections decreased from 8.51 to 5.25 deaths
per 100,000 persons. Thus, since 2012 the number of hepatitis C-related deaths
surpassed that of the 60 other notifiable infections.
The decline in deaths due to other infectious
diseases was mostly attributable to decreasing HIV-related mortality (from
15,168 to 8831 deaths; -41.8%), as well as declines in deaths due to
pneuomococcal disease (from 1283 to 885 deaths; -31.0%) and tuberculosis (from
1382 to 992 deaths; -28.2%).
"One explanation for the increasing
HCV-related mortality could be that many HCV-infected persons are not receiving
antiviral therapy and achieving a sustained virologic response indicative of a
cure," the authors wrote. One study found that only 19% of people with hepatitis
C and 16% of patients with HIV/HCV co-infection were eligible for and received
treatment; 13% and 11%, respectively, completed therapy; and 3% and 6%,
respectively, were cured.
Furthermore, they noted that in one analysis
only 19% of hepatitis C patients who died had HCV listed anywhere on their
death certificate – although 75% had indications of substantial or extensive
liver disease at time of death – leading them to believe that "these data
greatly underestimate the true hepatitis C mortality burden."
They suggested that "underappreciation of
the seriousness of HCV infection" may be due in part to "the lack of
cohesive and vocal advocacy groups as many patients were former injection drug
users" and "a new therapeutic nihilism not about the efficacy of
antivirals but about their perceived cost, despite evident
cost-effectiveness."
"The unabated increasing trend in the
number of hepatitis C-related deaths documented from 1999 to 2013,
predominantly among middle-aged persons, underscores the urgency in finding,
evaluating, and treating patients in the largest infectious disease epidemic in
the United States," the authors concluded.