- Email: [email protected]
P.442 HCV and HIV seroprevalences and at-risk behaviors among drug users, ANRS-Coquelicot study, France, 2004
Posters: 14. Epidemiology, public policy cause and CLD and HC as contributing causes. Population data from the US Census Bureau were used to calculate annual age-adjusted HC mortality rates. Linear models were fit to annual age-adjusted mortality rates to quantify rate changes over time. Results: Annual HC-related deaths increased from 2798 in 1995 to 7347 in 2003, representing a 135.2% increase in age-adjusted mortality rates (1.09 to 2.47 deaths/100,000 population). Ageadjusted mortality rates increased 90.9% from 1995 to 1999 (1.09 to 2.03 deaths/100,000) and increased 6.4% from 2000 to 2003 (2.34 to 2.47 deaths/100,000). A similar pattern was observed among males and females. However, among persons aged 45-54 and 55-64 mortality rates continued to rise substantially from 2000 to 2003, each increasing about 21% during that time. In 2003, mortality rates were 2.5 times higher in males than in females (3.58 versus 1.43/100,000) and age-specific mortality rates were highest among 45-54 year olds (8.17 deaths/100,000). In 2003, 932 HC-related deaths (12.7%) listed hepatocellular carcinoma and 389 (5.3%) listed HIV/AIDS as a cause of death. Conclusion: HC mortality rates increased substantially during 1995-2003, but more slowly after 1999 compared to earlier years. Observed increases early in the study period could be attributed to real increases in HC deaths and increased testing for HCV infection, while more recent trends likely reflect patterns in HC-related mortality. The number of deaths identified likely represents a minimum estimate because of the use of a highly specific case definition and underreporting of HC on death certificates. Elevated mortality rates among males and 45-54 year olds are consistent with HC prevalence data. :
~
Prevalence of hepatitis B and hepatitis C in France, 2004
C. Meffre 1 *, E. DelarocqueAstagneau 1, Y. LeStrat 1, F. Dubois 2, J. Steinmetz 3, J.M. Lemasson 4, D. Coste 5, J.E Meyer6, D. Antona 1, J. Warszawski 7, S. Leiser 8, J.R Giordanella 8, R. Gu~guen 3, J.C. Desenclos 1. 1Infectious Disease Department, National Institute
for Public Health Surveillance, Saint-Maurice; 2Laboratory, IRSA, Tours; 3Laboratory and Statistics Department, Social Security Health Centers Coordinating Unit, Saint-Etienne; 4Laboratory, 5Medical Department, Social Security Health Center, Poitiers; 6Laboratory, Social Security Health Center, Saint-Brieuc; 7Unit 569, INSERM, Le Kremfin-Bic#tre; 8Health Poficy Department, CNAMTS, Paris, France Background and Objectives: In France, a first national prevalence survey of hepatitis C markers was conducted in 1994. Hepatitis B markers prevalence estimates were obtained from heterogeneous sources in the early 1990s. In order to monitor the prevalence of these infections and to evaluate the impact of prevention efforts, a cross-sectional survey was conducted in 2004 among French metropolitan residents. Methods: A two-stage, stratified, random and proportional probability sample design was used. The survey included 14,416 participants aged 18-80 who came to selected social security health centers and gave informed consent. Information was collected on demographic, occupational, behavioural characteristics and history of nosocomial exposure. Serum samples were tested for antibody to HCV (anti-HCV), HCV RNA, anti-HBc antibodies and for HBs antigen (HBsAg). Data were analysed with SUDAAN ® software. Results are weighted estimates for the French metropolitan population. Results: The overall prevalence of anti-HCV was 0.84% (95% CI: 0.65-1.10), corresponding to 367,055 persons nationwide (95% CI: 269,361-464,750). Among the anti-HCV positive persons, 57% (95% CI: 43-71) knew their sero-status and 65% (95% CI: 50-78) were positive for HCVRNA, indicating that 221,386 persons (95% CI: 158,909-283,862) were chronically infected. In multivariate analysis, factors associated with anti-HCV seropositivity were: IV drug use, nasal drug use, blood transfusion, prior surgery, tattoo, age over 29, social deprivation, birth-continent where anti-HCV prevalence >2.5%. The HBsAg prevalence was 0.65% (95%C1: 0.45-0.93) corresponding to 280,821 chronic carriers (95%C1: 179,730-381,913). Among these, 45% (95% CI: 23-69) knew they were HBsAg seropositive. In multivariate analysis, factors associated with seropositivity for anti-HBc were: IV drug use, blood transfusion, homosexuality, social deprivation, less than 12 years of education,
$197 accidental needle-stick injuries, highly endemic birth-continent (HBsAg prevalence >8%), age over 29. Conclusion: In 2004, the anti-HCV prevalence is close to the 1990s estimates (1.05%; 95% CI: 0.75-1.34) whereas H BsAg prevalence is higher than the previous estimates (0.2-0.4%). Current screening policy should be sustained for hepatitis C. HBsAg screening should be strengthened.
•lP.•
Serological, epidemiological and molecular aspects of hepatitis B virus infection in the largest Afro-Brazilian isolated community
R. Martins 1 *, M. Dias 1, S. Teles 1, A. Motta-Castro 2, S. Gomes 3.
1Universidade Federal de Goias, Goias; 2Universidade Federal de Mate Grosso do Sul, Mate Grosso do Sul; 3Institute Oswaldo Cruz, Rio de Janeiro, Brazil Background and Objectives: Hepatitis B virus (HBV) infection prevalence and genotypes have distinct geographical distribution. In Brazil, African individuals were introduced by slave trade. Some of them escaped from gold mines or farms and stayed in isolated communities, called "Quilombos", without significant additional admixture since their establishment. In this study, the prevalence of HBV infection in the largest Afro-Brazilian isolated community was sought. Risk factors associated with this infection and HBV genotypes distribution were also determined. Methods: A total of 878 individuals living in the Kalunga community in the State of Goi~s, Central Brazil, were interviewed for possible risk factors and serum samples screened for the presence of HBV serological markers. HBV positive sera were tested for HBV DNA by polymerase chain reaction and positive samples were genotyped by restriction fragment length polymorphism (RFLP). Results: Of the 878 individuals, 16 (1.8%) were positive for HBsAg and anti-HBc, 19 (2.2%) were anti-HBc only, and 276 (31.4%) had anti-HBs and anti-HBc markers, resulting in an overall HBV infection prevalence of 35.4% (95% CI: 32.3-38.7). Multivariate analysis of risk factors showed that mean age, male gender, illiteracy and history of multiple sexual partners were associated with this infection. HBVDNA was present in 75% (12/16) of the HBsAg and antiHBc positive serum samples. Of these, genotyping was performed in 11 samples: 10 (91%) belonged to genotype A (subtype Aa) and 1 (9%) to genotype R All anti-HBc only positive samples were HBVDNA negative. Five anti-HBs and anti-HBc positive samples were HBV DNA positive (genotype A, subtype Aa), resulting in an occult HBV infection rate of 1.7% (5/295) among anti-HBc positive individuals. Conclusion: The present study showed higher prevalence rates for the overall HBV infection and HBsAg in this community, when compared with rates found in local blood donors (10.7% and 0.8% for anti-HBc and HBsAg markers in blood donors, respectively). In addition, our findings suggest that the presence of HBV isolates from genotype A (subtype Aa) in Brazil may be the result of the displacement of African populations during the slavery trade period. Financial support: CNPq.
IR•
HCV and HIV seroprevalences and at-risk behaviors among drug users, ANRS-Coquelicot study, France, 2004
M. Jauffret-Roustide 1 *, E. Couturier 1, F. Barin 2, Y. Le Strat 1, J. Emmanuelli 1, C. Semaille 1, J. Desenclos 1. 1Maladies
Infectieuses, Institut de Veille Sanitaire, Saint-Maurice; 2Laboratoire de Virologie, CHU Bretonneau, Tours, France Background and Objectives: In France, a harm reduction policy was implemented for drug users (DUs) in 1993. Prevalence surveys among DUs monitored self-report HIV and HCV prevalences. Selfreport underestimates HCV prevalence. We did a seroepidemiological study among DUs in 2004 to estimate HCV and HIV seroprevalences, to compare self-reported and biologic prevalences, and to describe at-risk behaviors. Methods: Between September and December 2004, a crosssectional multicenter survey was done among DUs having injected
$198
Journal of Clinical Virology 2006, Vol 36 (suppl 2)
or snorted drugs at least once. DUs were recruited through lowthreshold services, needle exchange programs, drug treatment centers, post-treatment centers, therapeutic apartments and general practitioners. DUs were included according to a two-stage stratified sampling design. First, services and survey days were randomly selected. Second, DUs were randomly selected among attendees in those days. A sociobehavioral questionnaire was administered by professional interviewers. Selected DUs were also asked to selfcollect a fingerprick blood sample with a micro-blade on blotting paper. Blotting papers were tested for HIV and HCV antibodies by EIA. Prevalences and proportions were estimated taking into account the survey design using the Stata8 software. Results: Of all DUs selected, 1462 (61%) accepted to participate. HCV seroprevalence was 58.5% [ 95% Confidence Interval (CI): 51.4-65.2]. Of HCV-infected DUs, 32% [95% CI: 24.2-41.7] were unaware of their status. Of DUs under 30 years, 33% [95%C1: 19.6-49.2] were HCV seropositive. HIV seroprevalence was 9% [95% CI: 6.1-12.8]. HIV self-reported prevalence was 13.3% [9.8-17.8]. Only 0.3% [95% CI: 0.7-1.4] of DUs under 30 years were HIV positive. Of all DUs, 9% [95%C1: 5.8-11.3] were HIV/HCV coinfected. During the month prior to interview, 15% of DUs had shared syringe(s), 35% other injection equipment, and 28% snorting equipment. Sharing of injection equipment was more frequent among DUs under 30 years (48%) than among older DUs (29.3%), p<0.06. Conclusion: According to previous studies, harm-reduction policy seems to have had a marked impact on HIV transmission among French DUs (40% in 1988 versus 20% in 1996), but a much more limited impact on HCV (51% in 1993 versus 57% in 1996). Our results suggest that self-report was reliable for HIV but not for HCV, stressing the need for regular HCV testing of DUs. High HCV seroprevalence among young DUs suggests that they had been infected early during drug use. High-risk behaviours persist, particularly among young DUs which may contribute to sustain HCV and HIV transmission in this population in years to come.
I - P - - ~ Sustained transmission of hepatitis B in the Netherlands, despite vaccination targeted towards high-risk groups R. Van Houdt 1 *, S.M. Bruisten 1, N.H.T.M. Dukers 1, J.A.R. Van den Hoek 1, R.A. Coutinho 2, M. Mostert 3, H.G.M. Niesters 4, J. Richardus 4, R.A. De Man 4, E.L.M. Op de Coul s, F.D.H. Koedijk s, M.J.W. Van de Laar s, H.J. Boot s. 1Infectious Diseases, 2GGD, Health Service, Amsterdam; 3Infectious Diseases, GGD, Health Service, 4 Virology, Erasmus MC, Rotterdam; 5Centre of Infectious Diseases Control, National Institute for Health and Environment, Bilthoven, Netherlands
Background and Objectives: The Netherlands is a low endemic country for hepatitis B virus (HBV), which is why the Netherlands adopted a policy of vaccination targeted towards high-risk groups, rather than universal vaccination. Through molecular epidemiology we wanted to gain insight in the occurrence and spread of HBV throughout the Netherlands. Methods: During 2004, epidemiological data and blood samples were collected from all reported cases of acute HBV infection in the Netherlands. HBV cases were classified according to mode of transmission. A fragment of the S-gene of HBV (648bp) was amplified, sequenced and subjected to phylogenetic analysis to further clarify transmission patterns. Results: The incidence of HBV in 2004 was 1.8 per 100,000 inhabitants. The incidence of HBV infections was higher in urban areas. Of 291 acute HBV cases reported in 2004, 158 (54%) samples were available for genotyping. Phylogenetic analysis identified 6 genotypes: A (64%), B (3%), C (3%), D (21%), E (5%) and F (5%). The different HBV genotypes were evenly distributed over the Netherlands. Most cases (86%) of HBV infected men having sex with men (MSM) were infected with genotype A, accounting for 43% of all individuals within this genotype. There were only 3 reported cases of injecting drug use of which 1 was available for sequencing (genotype A). In contrast to the genotype A cluster, the sequences within the genotype D cluster were very heterogenic. Despite this heterogeneity, 2 sub-clusters could be identified, which were linked to Turkey and Morocco. Within genotype F, we identified
Abstracts, 12th ISHVLD a cluster linked to a Venezuelan strain, but the cases were not epidemiologically linked to one another. Conclusion: Genotype A is predominant in the Netherlands, especially amongst MSM, living in urban areas. Next to MSM, ethnic groups play an important role in HBV transmission in the Netherlands. We will continue this survey the next years in order to evaluate the targeted vaccination program.
IP.~]
Evaluation of the hepatitis B vaccination program targeted towards high-risk groups in Amsterdam, the Netherlands
R. Van Houdt*, G.J. Sonder, N.H.T.M. Dukers, L.IRM.J. Bovee, J.A.R. Van den Hoek, R.A. Coutinho, S.M. Bruisten. Infectious Diseases, GGD, Health Service, Amsterdam, Netherlands
Background and Objectives: The Netherlands has adopted a policy of hepatitis B virus (HBV) vaccination targeted towards highrisk groups, rather than universal vaccination. In 1998, the targeted program started as a pilot in Amsterdam. To evaluate this program, we performed a retrospective molecular epidemiological study covering the 12-year period 1992-2003 in Amsterdam. Methods: Reported acute HBV cases were classified according to most probable mode of transmission. The number of susceptibles among drug users and men having sex with men (MSM) was estimated using data from the Amsterdam Cohort Studies (ACS) and the city's vaccination data. A retrospective DNA sequencing study was performed on 85 sera from reported cases of acute HBV in Amsterdam. The S-gene (nucleotide 112-778) was sequenced. Sequence data were then subjected to phylogenetic analysis. Finally, the molecular data were linked and compared to the epidemiological data. Results: Approximately 2300 MSM, 400 drug users and 280 commercial sex workers were fully vaccinated in 1998-2003. The number of reported cases of acute HBV in Amsterdam declined from 214 in 1992-1997 to 128 in 1998-2003. Before 1998 there were no vaccination programs in the Netherlands. Despite the vaccination program, the percentage of susceptible drug users within the highrisk population of the ACS remained high (35%). However, after 1998 there were no reported cases of acute HBV among injecting drug users (IDUs). Although the percentage of susceptible MSM in Amsterdam declined due to the vaccination program, being 27% according to the ACS, the number of reported cases of acute HBV among MSM remained stable and MSM became the largest transmission category. Based on phylogenetic analysis, in the 6 years before vaccination started, three main clusters could be distinguished: (I) men having sex with men (MSM, genotype A), (11) Moroccan (genotype D), and (111) IDUs and their heterosexual partners cluster (genotype D). After 1998, the IDUs and their heterosexual partners cluster had fully disappeared. Strikingly, the same virus strain kept circulating among MSM in Amsterdam in the 12-year study period. Conclusion: The decline of acute HBV in Amsterdam is mainly due to a lack of reported cases of IDUs and their heterosexual partners in recent years, probably because of the decline in IDUs seen in Amsterdam after 1998. In the light of increased sexual risk behavior among MSM in Amsterdam in the last decade, the vaccination program among MSM has at best prevented an increase in acute infections.
IP_~
The knowledge and behaviors of HCV-infected persons identified in a seroprevalence survey, USA, 2001-2002
A. Wasley*, L. Finelli, B. Bell, M. Alter. Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, USA
Background and Objectives: An estimated 3.2 million persons in the USA are infected with hepatitis C virus (HCV), but the number of these persons who are aware of their infection and received medical follow-up is unknown. Methods: NHANES (National Health and Nutrition Examination Survey) is a periodic survey of a representative sample of the noninstitutionalized US population designed to estimate the prevalence of a range of health outcomes and behaviors. Serum samples from participants >~6 years of age in 2001-2002 were tested for
~
Prevalence of hepatitis B and hepatitis C in France, 2004
C. Meffre 1 *, E. DelarocqueAstagneau 1, Y. LeStrat 1, F. Dubois 2, J. Steinmetz 3, J.M. Lemasson 4, D. Coste 5, J.E Meyer6, D. Antona 1, J. Warszawski 7, S. Leiser 8, J.R Giordanella 8, R. Gu~guen 3, J.C. Desenclos 1. 1Infectious Disease Department, National Institute
for Public Health Surveillance, Saint-Maurice; 2Laboratory, IRSA, Tours; 3Laboratory and Statistics Department, Social Security Health Centers Coordinating Unit, Saint-Etienne; 4Laboratory, 5Medical Department, Social Security Health Center, Poitiers; 6Laboratory, Social Security Health Center, Saint-Brieuc; 7Unit 569, INSERM, Le Kremfin-Bic#tre; 8Health Poficy Department, CNAMTS, Paris, France Background and Objectives: In France, a first national prevalence survey of hepatitis C markers was conducted in 1994. Hepatitis B markers prevalence estimates were obtained from heterogeneous sources in the early 1990s. In order to monitor the prevalence of these infections and to evaluate the impact of prevention efforts, a cross-sectional survey was conducted in 2004 among French metropolitan residents. Methods: A two-stage, stratified, random and proportional probability sample design was used. The survey included 14,416 participants aged 18-80 who came to selected social security health centers and gave informed consent. Information was collected on demographic, occupational, behavioural characteristics and history of nosocomial exposure. Serum samples were tested for antibody to HCV (anti-HCV), HCV RNA, anti-HBc antibodies and for HBs antigen (HBsAg). Data were analysed with SUDAAN ® software. Results are weighted estimates for the French metropolitan population. Results: The overall prevalence of anti-HCV was 0.84% (95% CI: 0.65-1.10), corresponding to 367,055 persons nationwide (95% CI: 269,361-464,750). Among the anti-HCV positive persons, 57% (95% CI: 43-71) knew their sero-status and 65% (95% CI: 50-78) were positive for HCVRNA, indicating that 221,386 persons (95% CI: 158,909-283,862) were chronically infected. In multivariate analysis, factors associated with anti-HCV seropositivity were: IV drug use, nasal drug use, blood transfusion, prior surgery, tattoo, age over 29, social deprivation, birth-continent where anti-HCV prevalence >2.5%. The HBsAg prevalence was 0.65% (95%C1: 0.45-0.93) corresponding to 280,821 chronic carriers (95%C1: 179,730-381,913). Among these, 45% (95% CI: 23-69) knew they were HBsAg seropositive. In multivariate analysis, factors associated with seropositivity for anti-HBc were: IV drug use, blood transfusion, homosexuality, social deprivation, less than 12 years of education,
$197 accidental needle-stick injuries, highly endemic birth-continent (HBsAg prevalence >8%), age over 29. Conclusion: In 2004, the anti-HCV prevalence is close to the 1990s estimates (1.05%; 95% CI: 0.75-1.34) whereas H BsAg prevalence is higher than the previous estimates (0.2-0.4%). Current screening policy should be sustained for hepatitis C. HBsAg screening should be strengthened.
•lP.•
Serological, epidemiological and molecular aspects of hepatitis B virus infection in the largest Afro-Brazilian isolated community
R. Martins 1 *, M. Dias 1, S. Teles 1, A. Motta-Castro 2, S. Gomes 3.
1Universidade Federal de Goias, Goias; 2Universidade Federal de Mate Grosso do Sul, Mate Grosso do Sul; 3Institute Oswaldo Cruz, Rio de Janeiro, Brazil Background and Objectives: Hepatitis B virus (HBV) infection prevalence and genotypes have distinct geographical distribution. In Brazil, African individuals were introduced by slave trade. Some of them escaped from gold mines or farms and stayed in isolated communities, called "Quilombos", without significant additional admixture since their establishment. In this study, the prevalence of HBV infection in the largest Afro-Brazilian isolated community was sought. Risk factors associated with this infection and HBV genotypes distribution were also determined. Methods: A total of 878 individuals living in the Kalunga community in the State of Goi~s, Central Brazil, were interviewed for possible risk factors and serum samples screened for the presence of HBV serological markers. HBV positive sera were tested for HBV DNA by polymerase chain reaction and positive samples were genotyped by restriction fragment length polymorphism (RFLP). Results: Of the 878 individuals, 16 (1.8%) were positive for HBsAg and anti-HBc, 19 (2.2%) were anti-HBc only, and 276 (31.4%) had anti-HBs and anti-HBc markers, resulting in an overall HBV infection prevalence of 35.4% (95% CI: 32.3-38.7). Multivariate analysis of risk factors showed that mean age, male gender, illiteracy and history of multiple sexual partners were associated with this infection. HBVDNA was present in 75% (12/16) of the HBsAg and antiHBc positive serum samples. Of these, genotyping was performed in 11 samples: 10 (91%) belonged to genotype A (subtype Aa) and 1 (9%) to genotype R All anti-HBc only positive samples were HBVDNA negative. Five anti-HBs and anti-HBc positive samples were HBV DNA positive (genotype A, subtype Aa), resulting in an occult HBV infection rate of 1.7% (5/295) among anti-HBc positive individuals. Conclusion: The present study showed higher prevalence rates for the overall HBV infection and HBsAg in this community, when compared with rates found in local blood donors (10.7% and 0.8% for anti-HBc and HBsAg markers in blood donors, respectively). In addition, our findings suggest that the presence of HBV isolates from genotype A (subtype Aa) in Brazil may be the result of the displacement of African populations during the slavery trade period. Financial support: CNPq.
IR•
HCV and HIV seroprevalences and at-risk behaviors among drug users, ANRS-Coquelicot study, France, 2004
M. Jauffret-Roustide 1 *, E. Couturier 1, F. Barin 2, Y. Le Strat 1, J. Emmanuelli 1, C. Semaille 1, J. Desenclos 1. 1Maladies
Infectieuses, Institut de Veille Sanitaire, Saint-Maurice; 2Laboratoire de Virologie, CHU Bretonneau, Tours, France Background and Objectives: In France, a harm reduction policy was implemented for drug users (DUs) in 1993. Prevalence surveys among DUs monitored self-report HIV and HCV prevalences. Selfreport underestimates HCV prevalence. We did a seroepidemiological study among DUs in 2004 to estimate HCV and HIV seroprevalences, to compare self-reported and biologic prevalences, and to describe at-risk behaviors. Methods: Between September and December 2004, a crosssectional multicenter survey was done among DUs having injected
$198
Journal of Clinical Virology 2006, Vol 36 (suppl 2)
or snorted drugs at least once. DUs were recruited through lowthreshold services, needle exchange programs, drug treatment centers, post-treatment centers, therapeutic apartments and general practitioners. DUs were included according to a two-stage stratified sampling design. First, services and survey days were randomly selected. Second, DUs were randomly selected among attendees in those days. A sociobehavioral questionnaire was administered by professional interviewers. Selected DUs were also asked to selfcollect a fingerprick blood sample with a micro-blade on blotting paper. Blotting papers were tested for HIV and HCV antibodies by EIA. Prevalences and proportions were estimated taking into account the survey design using the Stata8 software. Results: Of all DUs selected, 1462 (61%) accepted to participate. HCV seroprevalence was 58.5% [ 95% Confidence Interval (CI): 51.4-65.2]. Of HCV-infected DUs, 32% [95% CI: 24.2-41.7] were unaware of their status. Of DUs under 30 years, 33% [95%C1: 19.6-49.2] were HCV seropositive. HIV seroprevalence was 9% [95% CI: 6.1-12.8]. HIV self-reported prevalence was 13.3% [9.8-17.8]. Only 0.3% [95% CI: 0.7-1.4] of DUs under 30 years were HIV positive. Of all DUs, 9% [95%C1: 5.8-11.3] were HIV/HCV coinfected. During the month prior to interview, 15% of DUs had shared syringe(s), 35% other injection equipment, and 28% snorting equipment. Sharing of injection equipment was more frequent among DUs under 30 years (48%) than among older DUs (29.3%), p<0.06. Conclusion: According to previous studies, harm-reduction policy seems to have had a marked impact on HIV transmission among French DUs (40% in 1988 versus 20% in 1996), but a much more limited impact on HCV (51% in 1993 versus 57% in 1996). Our results suggest that self-report was reliable for HIV but not for HCV, stressing the need for regular HCV testing of DUs. High HCV seroprevalence among young DUs suggests that they had been infected early during drug use. High-risk behaviours persist, particularly among young DUs which may contribute to sustain HCV and HIV transmission in this population in years to come.
I - P - - ~ Sustained transmission of hepatitis B in the Netherlands, despite vaccination targeted towards high-risk groups R. Van Houdt 1 *, S.M. Bruisten 1, N.H.T.M. Dukers 1, J.A.R. Van den Hoek 1, R.A. Coutinho 2, M. Mostert 3, H.G.M. Niesters 4, J. Richardus 4, R.A. De Man 4, E.L.M. Op de Coul s, F.D.H. Koedijk s, M.J.W. Van de Laar s, H.J. Boot s. 1Infectious Diseases, 2GGD, Health Service, Amsterdam; 3Infectious Diseases, GGD, Health Service, 4 Virology, Erasmus MC, Rotterdam; 5Centre of Infectious Diseases Control, National Institute for Health and Environment, Bilthoven, Netherlands
Background and Objectives: The Netherlands is a low endemic country for hepatitis B virus (HBV), which is why the Netherlands adopted a policy of vaccination targeted towards high-risk groups, rather than universal vaccination. Through molecular epidemiology we wanted to gain insight in the occurrence and spread of HBV throughout the Netherlands. Methods: During 2004, epidemiological data and blood samples were collected from all reported cases of acute HBV infection in the Netherlands. HBV cases were classified according to mode of transmission. A fragment of the S-gene of HBV (648bp) was amplified, sequenced and subjected to phylogenetic analysis to further clarify transmission patterns. Results: The incidence of HBV in 2004 was 1.8 per 100,000 inhabitants. The incidence of HBV infections was higher in urban areas. Of 291 acute HBV cases reported in 2004, 158 (54%) samples were available for genotyping. Phylogenetic analysis identified 6 genotypes: A (64%), B (3%), C (3%), D (21%), E (5%) and F (5%). The different HBV genotypes were evenly distributed over the Netherlands. Most cases (86%) of HBV infected men having sex with men (MSM) were infected with genotype A, accounting for 43% of all individuals within this genotype. There were only 3 reported cases of injecting drug use of which 1 was available for sequencing (genotype A). In contrast to the genotype A cluster, the sequences within the genotype D cluster were very heterogenic. Despite this heterogeneity, 2 sub-clusters could be identified, which were linked to Turkey and Morocco. Within genotype F, we identified
Abstracts, 12th ISHVLD a cluster linked to a Venezuelan strain, but the cases were not epidemiologically linked to one another. Conclusion: Genotype A is predominant in the Netherlands, especially amongst MSM, living in urban areas. Next to MSM, ethnic groups play an important role in HBV transmission in the Netherlands. We will continue this survey the next years in order to evaluate the targeted vaccination program.
IP.~]
Evaluation of the hepatitis B vaccination program targeted towards high-risk groups in Amsterdam, the Netherlands
R. Van Houdt*, G.J. Sonder, N.H.T.M. Dukers, L.IRM.J. Bovee, J.A.R. Van den Hoek, R.A. Coutinho, S.M. Bruisten. Infectious Diseases, GGD, Health Service, Amsterdam, Netherlands
Background and Objectives: The Netherlands has adopted a policy of hepatitis B virus (HBV) vaccination targeted towards highrisk groups, rather than universal vaccination. In 1998, the targeted program started as a pilot in Amsterdam. To evaluate this program, we performed a retrospective molecular epidemiological study covering the 12-year period 1992-2003 in Amsterdam. Methods: Reported acute HBV cases were classified according to most probable mode of transmission. The number of susceptibles among drug users and men having sex with men (MSM) was estimated using data from the Amsterdam Cohort Studies (ACS) and the city's vaccination data. A retrospective DNA sequencing study was performed on 85 sera from reported cases of acute HBV in Amsterdam. The S-gene (nucleotide 112-778) was sequenced. Sequence data were then subjected to phylogenetic analysis. Finally, the molecular data were linked and compared to the epidemiological data. Results: Approximately 2300 MSM, 400 drug users and 280 commercial sex workers were fully vaccinated in 1998-2003. The number of reported cases of acute HBV in Amsterdam declined from 214 in 1992-1997 to 128 in 1998-2003. Before 1998 there were no vaccination programs in the Netherlands. Despite the vaccination program, the percentage of susceptible drug users within the highrisk population of the ACS remained high (35%). However, after 1998 there were no reported cases of acute HBV among injecting drug users (IDUs). Although the percentage of susceptible MSM in Amsterdam declined due to the vaccination program, being 27% according to the ACS, the number of reported cases of acute HBV among MSM remained stable and MSM became the largest transmission category. Based on phylogenetic analysis, in the 6 years before vaccination started, three main clusters could be distinguished: (I) men having sex with men (MSM, genotype A), (11) Moroccan (genotype D), and (111) IDUs and their heterosexual partners cluster (genotype D). After 1998, the IDUs and their heterosexual partners cluster had fully disappeared. Strikingly, the same virus strain kept circulating among MSM in Amsterdam in the 12-year study period. Conclusion: The decline of acute HBV in Amsterdam is mainly due to a lack of reported cases of IDUs and their heterosexual partners in recent years, probably because of the decline in IDUs seen in Amsterdam after 1998. In the light of increased sexual risk behavior among MSM in Amsterdam in the last decade, the vaccination program among MSM has at best prevented an increase in acute infections.
IP_~
The knowledge and behaviors of HCV-infected persons identified in a seroprevalence survey, USA, 2001-2002
A. Wasley*, L. Finelli, B. Bell, M. Alter. Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, USA
Background and Objectives: An estimated 3.2 million persons in the USA are infected with hepatitis C virus (HCV), but the number of these persons who are aware of their infection and received medical follow-up is unknown. Methods: NHANES (National Health and Nutrition Examination Survey) is a periodic survey of a representative sample of the noninstitutionalized US population designed to estimate the prevalence of a range of health outcomes and behaviors. Serum samples from participants >~6 years of age in 2001-2002 were tested for