Global epidemiology of hepatitis B and hepatitis C in people who inject drugs: results of systematic reviews.

[Guest guest]

Lancet. 2011 Jul 27. [Epub ahead of print]

Global epidemiology of hepatitis B and hepatitis C in people who inject drugs:

results of systematic reviews.

PK, Mathers BM, Cowie B, Hagan H, Des Jarlais D, Horyniak D, Degenhardt

L.

Source

National Drug and Alcohol Research Centre, University of New South Wales,

Sydney, NSW, Australia.

Abstract

BACKGROUND:

Injecting drug use is an important risk factor for transmission of viral

hepatitis, but detailed, transparent estimates of the scale of the issue do not

exist. We estimated national, regional, and global prevalence and population

size for hepatitis C virus (HCV) and hepatitis B virus (HBV) in injecting drug

users (IDUs).

METHODS:

We systematically searched for data for HBV and HCV in IDUs in peer-reviewed

databases (Medline, Embase, and PsycINFO), grey literature, conference

abstracts, and online resources, and made a widely distributed call for

additional data. From 4386 peer-reviewed and 1019 grey literature sources, we

reviewed 1125 sources in full. We extracted studies into a customised database

and graded them according to their methods. We included serological reports of

HCV antibodies (anti-HCV), HBV antibodies (anti-HBc), or HBV surface antigen

(HBsAg) in studies of IDUs with more than 40 participants (<100% HIV-positive)

and sampling frames that did not exclude participants on the basis of age or

sex. With endorsed decision rules, we calculated prevalence estimates with

anti-HCV and anti-HBc as proxies for exposure and HBsAg as proxy for current

infection. We combined these estimates with IDU population sizes to calculate

the number of IDUs with positive HBV or HCV statuses.

FINDINGS:

We located eligible reports with data for prevalence of anti-HCV in IDUs for 77

countries; midpoint prevalence estimates suggested 60-80% of IDUs had anti-HCV

in 25 countries and more than 80% of IDUs did so in 12 countries. About 10.0

million (range 6.0-15.2) IDUs worldwide might be anti-HCV positive. China (1.6

million), USA (1.5 million), and Russia (1.3 million) had the largest such

populations. We identified eligible HBsAg reports for 59 countries, with

midpoint prevalence estimates of 5-10% in 21 countries and more than 10% in ten

countries. Worldwide, we estimate 6.4 million IDUs are anti-HBc positive

(2.3-9.7 million), and 1.2 million (0.3-2.7 million) are HBsAg positive.

INTERPRETATION:

More IDUs have anti-HCV than HIV infection, and viral hepatitis poses a key

challenge to public health. Variation in the coverage and quality of existing

research creates uncertainty around estimates. Improved and more complete data

and reporting are needed to estimate the scale of the issue, which will inform

efforts to prevent and treat HCV and HBV in IDUs.

FUNDING:

WHO and US National Institutes of Health (NIDA R01 DA018609).

Copyright © 2011 Elsevier Ltd. All rights reserved.

PMID: 21802134 [PubMed - as supplied by publisher]