End Hep C SF, a consortium of public health workers, medical providers, advocates and
people living with hepatitis C, has released the first-ever estimate of the
number of people thought to be living with active hepatitis C virus (HCV)
infection in San Francisco.

The new estimate suggests that nearly 13,000 city residents are
currently living with hepatitis C. People who inject drugs, baby boomers and
men who have sex with men are disproportionately affected, according to a summary of the report. Complete findings will appear in a forthcoming
medical journal article.

San Francisco is one of the only cities in the US to have a robust
estimate of how many people are living with hepatitis C, said Emalie Huriaux of
Project Inform, who sits on the End Hep C SF steering committee.

“Having this information is critical, as it both illustrates the great
impact hepatitis C has on the city – with nearly two out of every 100 residents
living with the virus – and it gives us a baseline by which we can measure our
success toward the goal of eliminating the public health threat of hepatitis C
in San Francisco,” Huriaux said.

Hepatitis C
often has no symptoms at early stages and many people are not aware they carry
the virus. But over years or decades, chronic HCV infection can lead to serious
liver disease including cirrhosis and liver cancer. There are now effective and
well-tolerated treatments that can cure most people in two to three months, but
due to their high cost they are not available to everyone who needs them.

To learn more about the hepatitis C epidemic in San
Francisco, End Hep C SF compiled and analysed public health data from multiple
sources.

The study found that approximately
23,000 people – or 2.7% of the 2015 San Francisco population of about 860,000 –
have antibodies against HCV, indicating past exposure to the virus. This is
significantly higher than the national antibody prevalence of about 1.7%, according to the report.

About one in five people will clear HCV naturally, and
others do so with treatment, leaving an estimated 13,000 people – or about 1.5%
of the population – with active infection. People with active HCV infection are
susceptible to progressive liver damage and can transmit the virus to others.

Nationwide, the Centers for Disease Control and
Prevention (CDC) estimates that approximately 3.5 million people are currently living
with HCV, out of a total population of around 325,000 million.

The new San Francisco data reveal substantial differences
in hepatitis C rates across population subgroups.

In San Francisco, as is the case nationwide and
globally, people who inject drugs have the highest likelihood of having
hepatitis C, as the virus is readily transmitted via syringes and other drug injection
equipment. While people who inject drugs make up only 3% of the city’s total
population, they account for 70% of people with active HCV infection.

Baby boomers – people born between 1945 and 1965 –
traditionally have the highest rate of hepatitis C in the US, and the CDC
recommends that everyone in this age group should
be screened for HCV at least once
. In San Francisco, this age group
makes up 21% of the population, but accounts for 38% of active HCV infections.

Gay and bisexual men, who make up around 8% of the city’s
population, account for 13% of active HCV infections, according to the report.
Sexually transmitted acute HCV infection is mostly seen among HIV-positive men who have sex with men. HCV transmission has been
linked to a variety of sexual activities including condomless anal sex and
fisting; it is not yet clear whether the virus is transmitted through semen as well as blood.

Transgender women in San Francisco appear to have a
particularly high rate of hepatitis C. Although this group makes up just 0.1%
of the city’s population, the report estimates that one in six may be living
with HCV.

The estimated 13,000 people with active HCV
infection is roughly similar to the approximately 16,000 people thought to be living with HIV in San Francisco. But
the distribution is quite different. Gay and bisexual men account for nearly
90% of people with HIV, while people who inject drugs account for about 20%
(some people fall into both categories). Nearly three-quarters of gay men with HCV also have HIV, according to the
report.

The consortium estimates that more than 4500 people
have been treated for hepatitis C based on reports from local health care facilities.
The report says that “a few thousand” people have been cured, but
this number is not easy to determine.
While the newest direct-acting antiviral therapies have cure rates exceeding 95%,
older therapies were less effective and many people stopped treatment early due
to side-effects.

“Given
recent medical advances, we now have the potential not just to reduce but to
eliminate hepatitis C as a public health threat in San Francisco,” concluded
End Hep C steering committee member Dr
Annie Luetkemeyer of the University of
California at San Francisco.