Changes in blood-borne infection risk among injection drug users

[Guest guest]

J Infect Dis. 2011 Mar;203(5):587-94. Epub 2011 Jan 31.

Changes in blood-borne infection risk among injection drug users.

Mehta SH, Astemborski J, Kirk GD, Strathdee SA, KE, Vlahov D, DL.

Department of Epidemiology, s Hopkins Bloomberg School of Public Health,

Baltimore, MD 21205, USA. shmehta@...

Comment in:

J Infect Dis. 2011 Mar;203(5):571-4.

Abstract

BACKGROUND: Population-level hepatitis C virus (HCV) infection incidence is a

surrogate for community drug-related risk.

METHODS: We characterized trends in human immunodeficiency virus (HIV) and HCV

infection incidence and HCV infection prevalence among injection drug users

(IDUs) recruited over 4 periods: 1988-1989, 1994-1995, 1998, and 2005-2008. We

calculated HIV and HCV infection incidence within the first year of follow-up

among IDUs whose test results were negative for these viruses at baseline (n =

2061 and n = 373, respectively). We used Poisson regression to compare trends

across groups.

RESULTS: HIV infection incidence declined significantly from 5.5 cases/100

person-years (py) in the 1988-1989 group to 2.0 cases/100 py in the 1994-1995

group to 0 cases/100 py in the 1998 and 2005-2008 groups. Concurrently, HCV

infection incidence declined but remained robust (22.0 cases/100 py in the

1988-1989 cohort to 17.2 cases/100 py in the 1994-1995 cohort, 17.9 cases/100 py

in the 1998 cohort, and 7.8 cases/100 py in the 2005-2008 cohort; P = .07).

Likewise, HCV infection prevalence declined, but chiefly in younger IDUs. For

persons aged <39 years, relative to the 1988-1989 cohort, all groups exhibited

significant declines (adjusted prevalence ratio [PR] for the 2005-08 cohort,

..73; 95% confidence interval [CI], .65-.81). However, for persons aged ™ 39

years, only the 2005-2008 cohort exhibited declining prevalence compared with

the 1988-1989 cohort (adjusted PR, .87; 95% CI, .77-.99).

CONCLUSIONS: Although efforts to reduce blood-borne infection incidence have had

impact, this work will need to be intensified for the most transmissible

viruses, such as HCV.

PMID: 21282191 [PubMed - indexed for MEDLINE]

[Guest guest]

J Infect Dis. 2011 Mar;203(5):587-94. Epub 2011 Jan 31.

Changes in blood-borne infection risk among injection drug users.

Mehta SH, Astemborski J, Kirk GD, Strathdee SA, KE, Vlahov D, DL.

Department of Epidemiology, s Hopkins Bloomberg School of Public Health,

Baltimore, MD 21205, USA. shmehta@...

Comment in:

J Infect Dis. 2011 Mar;203(5):571-4.

Abstract

BACKGROUND: Population-level hepatitis C virus (HCV) infection incidence is a

surrogate for community drug-related risk.

METHODS: We characterized trends in human immunodeficiency virus (HIV) and HCV

infection incidence and HCV infection prevalence among injection drug users

(IDUs) recruited over 4 periods: 1988-1989, 1994-1995, 1998, and 2005-2008. We

calculated HIV and HCV infection incidence within the first year of follow-up

among IDUs whose test results were negative for these viruses at baseline (n =

2061 and n = 373, respectively). We used Poisson regression to compare trends

across groups.

RESULTS: HIV infection incidence declined significantly from 5.5 cases/100

person-years (py) in the 1988-1989 group to 2.0 cases/100 py in the 1994-1995

group to 0 cases/100 py in the 1998 and 2005-2008 groups. Concurrently, HCV

infection incidence declined but remained robust (22.0 cases/100 py in the

1988-1989 cohort to 17.2 cases/100 py in the 1994-1995 cohort, 17.9 cases/100 py

in the 1998 cohort, and 7.8 cases/100 py in the 2005-2008 cohort; P = .07).

Likewise, HCV infection prevalence declined, but chiefly in younger IDUs. For

persons aged <39 years, relative to the 1988-1989 cohort, all groups exhibited

significant declines (adjusted prevalence ratio [PR] for the 2005-08 cohort,

..73; 95% confidence interval [CI], .65-.81). However, for persons aged ™ 39

years, only the 2005-2008 cohort exhibited declining prevalence compared with

the 1988-1989 cohort (adjusted PR, .87; 95% CI, .77-.99).

CONCLUSIONS: Although efforts to reduce blood-borne infection incidence have had

impact, this work will need to be intensified for the most transmissible

viruses, such as HCV.

PMID: 21282191 [PubMed - indexed for MEDLINE]