TY - JOUR
T1 - Prevalence and incidence of hepatitis C in injecting drug users attending genitourinary medicine clinics
AU - Balogun, Monsurudeen
AU - Murphy, N.
AU - Nunn, S.
AU - Grant, A.
AU - Andrews, Nicholas
AU - Teo, C. G.
AU - Ramsay, Mary
AU - Parry, John
PY - 2009
Y1 - 2009
N2 - Surveillance reports and prevalence studies have indicated that injecting drug users (IDUs) contribute more to the hepatitis C epidemic in the United Kingdom than any other risk group. Information on both the prevalence and incidence of hepatitis C in IDUs is therefore essential to understanding the epidemiology of this infection. The prevalence of hepatitis C in specimens from the Unlinked Anonymous Prevalence Monitoring Programme collected in 1995, 1996, 1998, 1999, 2000, and 2001 was determined using residual syphilis serology specimens from IDUs attending 15 genitourinary medicine (GUM) clinics in and outside London. These specimens were tested for antibodies to hepatitis C virus (anti-HCV). Using this cross-sectional design, anti-HCV-negative specimens were tested for HCV RNA to identify incident infections during the 'window' period of infection, and thus to estimate HCV incidence. Results of the multivariable analysis showed that there was marked variation in prevalence by clinic (P < 0·0001) and age (P < 0·0001). Overall the majority of infections were in males and the overall prevalence in injectors declined over the study period from 36·9% to 28·7%. The annual incidence in these injectors was estimated as being 3·01% (95% CI 1·25-6·73). Over the study period HCV incidence decreased by 1·2% per year. Genotyping of the incident infections identified the most common genotype as type 1 with type 3 being more frequently seen after 1998. Of the prevalent infections, genotype 1 was the most common. The study has confirmed a higher prevalence of anti-HCV in IDUs in the London area compared to those outside London. How representative of the current injecting drug user population are IDUs attending GUM clinics is unclear. Even so, such studies allow prevalence and incidence to be estimated in individuals who have ever injected drugs and inform ongoing public health surveillance.
AB - Surveillance reports and prevalence studies have indicated that injecting drug users (IDUs) contribute more to the hepatitis C epidemic in the United Kingdom than any other risk group. Information on both the prevalence and incidence of hepatitis C in IDUs is therefore essential to understanding the epidemiology of this infection. The prevalence of hepatitis C in specimens from the Unlinked Anonymous Prevalence Monitoring Programme collected in 1995, 1996, 1998, 1999, 2000, and 2001 was determined using residual syphilis serology specimens from IDUs attending 15 genitourinary medicine (GUM) clinics in and outside London. These specimens were tested for antibodies to hepatitis C virus (anti-HCV). Using this cross-sectional design, anti-HCV-negative specimens were tested for HCV RNA to identify incident infections during the 'window' period of infection, and thus to estimate HCV incidence. Results of the multivariable analysis showed that there was marked variation in prevalence by clinic (P < 0·0001) and age (P < 0·0001). Overall the majority of infections were in males and the overall prevalence in injectors declined over the study period from 36·9% to 28·7%. The annual incidence in these injectors was estimated as being 3·01% (95% CI 1·25-6·73). Over the study period HCV incidence decreased by 1·2% per year. Genotyping of the incident infections identified the most common genotype as type 1 with type 3 being more frequently seen after 1998. Of the prevalent infections, genotype 1 was the most common. The study has confirmed a higher prevalence of anti-HCV in IDUs in the London area compared to those outside London. How representative of the current injecting drug user population are IDUs attending GUM clinics is unclear. Even so, such studies allow prevalence and incidence to be estimated in individuals who have ever injected drugs and inform ongoing public health surveillance.
KW - Genotype
KW - Hepatitis C virus
KW - Incidence
KW - Injecting drug users
KW - Prevalence
KW - Window period infections
UR - http://www.scopus.com/inward/record.url?scp=67650477573&partnerID=8YFLogxK
U2 - 10.1017/S0950268808001660
DO - 10.1017/S0950268808001660
M3 - Article
C2 - 19102796
AN - SCOPUS:67650477573
SN - 0950-2688
VL - 137
SP - 980
EP - 987
JO - Epidemiology and Infection
JF - Epidemiology and Infection
IS - 7
ER -