HCV And HBV Spreading More Slowly Among Injection
Drug Users In San Francisco
Science Daily - Injection drug users are still at a
very high risk of acquiring hepatitis C (HCV) and
hepatitis B (HBV); however, needle-sharing is less
common, and users do not become infected as quickly
as they did in the past, according to a new study.
Both HCV and HBV raise the risk of liver cancer and
other life-threatening liver disease and past
studies have shown that most injection drug users
became infected with both viruses soon after they
take up the habit. To address this danger, groups
have implemented interventions such as needle
exchange programs for at-risk populations.
Recently, researchers sought to determine what
effect such interventions may have had, by
determining the current prevalence and patterns of
acquisition of those diseases among injection drug
users. The investigation was led by Fan-Chen Tseng
and Thomas R. O'Brien of the National Cancer
Institute, and Brian R. Edlin of Weill Cornell
Medical College's Center for the Study of Hepatitis
C and the former Director of the Urban Health Study
at the University of California, San Francisco.
They used data from the Urban Health Study, which
recruited injection drug users in the San Francisco
Bay area from 1986 to 2005. That study collected
demographic information along with blood samples
which were analyzed for seroprevalence of
blood-borne infections. Tseng and colleagues focused
on HCV and HBV antibody prevalence in users who
participated between 1998 and 2000 and compared them
to those of users who participated in 1987.
Of the 2,296 drug users included in the Urban Health
Study between 1998 and 2000, 91 percent had antibody
to HCV and 80 percent to HBV. However, those who had
recently started injecting drugs had far lower
rates. Only 47 percent of participants who had been
injecting drugs for less than two years were
infected with HCV, compared to 71 percent who had
been using for 6-9 years. Comparable rates among the
1987 population were 76 percent and 91 percent.
For HBV, about 5 percent of the population had
serologic evidence of vaccination against the virus.
Among the others, 41 percent of those who had
injected drugs for less than 2 years, and 57 percent
of those who had been using for 6-9 years were
infected. Comparable rates among the 1987 population
were 45 percent and 80 percent.
Only 34 percent of the participants from 1998-2000
said they had shared syringes in the past 30 days,
compared to about 59 percent who had done so in
1987.
Although the population examined in this study was
not a random sample, and the authors had no way to
pinpoint the reasons for the improvements over time,
the reductions in infection rates the authors
observed coincided with the institution of
street-based outreach, HIV counseling and testing,
and needle exchange programs.
The findings suggest that there is now a longer
window of opportunity for interventions among this
at-risk population. To reduce infection rates
further, the authors suggest, it is also of
paramount importance to reduce the number of people
who start injection drug use and to make substance
abuse treatment available to those who wish to stop.
The authors conclude, "It is encouraging that the
frequency of HCV and HBV appears to have decreased
markedly among new initiates to injection drug use
in the San Francisco Bay area. If the reductions in
the prevalence of these infections can be sustained,
the risk of end stage liver disease and liver cancer
should decrease in this population."
Reference: "Seroprevalence of Hepatitis C Virus and
Hepatitis B Virus Among San Francisco Injection Drug
Users, 1998-2000." Tseng, Fan-Chen; O'Brien, Thomas;
Zhang, Mingdong; Kral, Alex; Ortiz-Conde, Betty;
Lorvick, Jennifer; Busch, Michael P.; Edlin, Brian.
Hepatology; September 2007; (DOI: 10.1002/hep.21765).
Note: This story has been adapted from a news
release issued by John Wiley & Sons, Inc..
http://www.sciencedaily.com/releases/2007/09/070905123852.htm |
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