Enhanced surveillance of hepatitis C in the EU, 2006 - 2012.

Hepatitis C is a major public health issue across Europe, and with rapidly evolving developments in the therapeutic field, it is essential that countries have access to epidemiological information. In 2011, The European Centre for Disease Prevention and Control (ECDC) introduced enhanced surveillance of hepatitis C across EU/EEA countries collecting routine data from national notification systems using standardized case definitions. Data collected from 2006 to 2012 indicate a high burden of disease with great variation in reported cases between countries. Most cases occurred among young adult males, and although injecting drug use dominated across all cases, there were increasing numbers of acute cases reported among men who have sex with men. Geographically, the reported data were the inverse of what may be expected based on findings from recent prevalence surveys in a number of EU/EEA countries. Unexpectedly, low figures were reported through notification systems in some southern and eastern European countries where prevalence is known from surveys to be high. This discrepancy highlights the limitation of surveillance data for a disease such as hepatitis C which is largely asymptomatic until a late stage, so that notifications reflect testing practices rather than real occurrence of disease. Further improvements to the quality of the data are important to increase data utility. Improved understanding of national testing practices is necessary to allow a better interpretation of surveillance results. Additional epidemiological studies alongside routine case-based reporting in notification systems should also be considered to better estimate the true disease burden across Europe.

Enhanced surveillance of hepatitis B in the EU, 2006-2012.

Robust epidemiological information on hepatitis B is important to help countries plan prevention and control programmes and evaluate public health responses to control transmission. European Centre Disease Prevention and Control (ECDC) introduced enhanced surveillance of hepatitis B at EU/EEA level in 2011 to collate routine surveillance data from national notification systems. Analysis of the data collected for the years 2006-2012 shows a high burden of hepatitis B across Europe with 110 005 cases reported over the period with the majority of these cases being chronic infections. The most commonly reported routes of transmission in acute cases included heterosexual transmission, nosocomial transmission, injecting drug use and transmission among men who have sex with men. Mother-to-child transmission was the most common route reported for chronic cases. Trends over time were difficult to analyse as national reporting practices changed, but data suggest a downward trend in acute cases, which probably reflects the impact of the widespread implementation of vaccination programmes. Notifications of chronic infection varied across countries and showed discrepancy with the expected results based on findings from recent prevalence surveys. This indicated that notifications mirror local testing practices rather than real occurrence of disease. Improving the quality of the data and considering reported notifications alongside other data sources, such as local screening practices and vaccination policies, will improve the utility of the data.

Concurrent partnerships and sexual risk taking among African and Caribbean migrant populations in the Netherlands.

Concurrent partnerships have been recognized as a determinant for the spread of HIV and sexually transmitted infections (STIs). We studied the association of concurrent partnerships with sexual behaviour among heterosexual Caribbean and African migrants, who account for a disproportionate burden of STIs and HIV in the Netherlands. Of 1792 migrants, 15% reported concurrent sexual partners in the previous six months. In multivariate multinomial analyses, women were less likely to have concurrent partners than men and they were less likely than men to use condoms with concurrent partners. We could not identify an association with the observed HIV prevalence; however, migrants with concurrent partners were less likely to be tested for HIV. Of migrants tested for STIs, one in three migrants with concurrent partners was diagnosed with an STI. Prevention targeting migrants should address the promotion of HIV/STI testing and stress the potential acceleration of HIV and STI epidemics due to concurrency.

Disassortative sexual mixing among migrant populations in The Netherlands: a potential for HIV/STI transmission?

To gain insight into the transmission of HIV and sexually transmitted infection (STI) among large migrant groups in The Netherlands, we studied the associations between their demographic and sexual characteristics, in particular condom use, and their sexual mixing patterns with other ethnic groups. In 2002-2005, cross-sectional surveys were conducted among migrants from Surinam (Afro- and Hindo-), the Netherlands Antilles, Cape Verde, and Ghana at social venues in three large cities. A questionnaire was administrated and a saliva sample was collected for HIV antibody testing. Of 2105 migrants recruited, 1680 reported sexual contacts, of whom 41% mixed sexually with other ethnicities, including the indigenous Dutch population. Such disassortative mixing was associated with being second-generation migrant, having several sexual partners, and having a steady and concurrent casual partner. Less disassortative mixing occurred in participants reporting visiting the country of origin. The association between condom use and sexual mixing differed by gender, with men using condoms inconsistently being most likely to be mixing with the Dutch indigenous population. HIV infection and recent STI treatment were not associated with disassortative mixing. This study shows substantial sexual mixing among migrant groups. Since disassortative mixing is more prevalent in second-generation migrants, it might increase in the upcoming years. The mixing patterns in relation to concurrency and the reported condom use in this study suggest a possibly increased level of HIV/STI transmission not only within migrant groups but also between migrant groups, especially via men who mix with the indigenous population and via migrant women who mix with non-Dutch casual partners. Although the observed HIV prevalence in migrants (0.6%) is probably too low to lead to much HIV transmission between ethnicity groups, targeted prevention measures are needed to prevent transmission of other STI.

Surveillance and epidemiology of hepatitis B and C in Europe - a review.

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are frequent causes of acute and chronic hepatitis worldwide and leading causes for hepatic cirrhosis and cancer. There is a distinct geographical variation in HBV and HCV incidence and prevalence in the European Union (EU) and European Economic Area/European Free Trade Association (EEA/EFTA) member states and neighbouring countries. The HBV carrier prevalence ranges from 0.1 to 8.0% and that of HCV from 0.1 to 6.0%. Within the last few years, the HBV incidence has decreased while the HCV incidence has increased. Both diseases are concentrated in certain subpopulations, such as injecting drug users, with tens of times higher prevalence than in the general population. Most EU and EEA/EFTA countries have a surveillance system for HBV and HCV infections, but due to differences in system structures, reporting practices, data collection methods and case definitions used, the surveillance data are difficult to compare across countries. The harmonisation and strengthening of HBV and HCV surveillance at the European level is of utmost importance to obtain more robust data on these diseases.

Migrants travelling to their country of origin: a bridge population for HIV transmission?

BACKGROUND: By having unprotected heterosexual contact in both The Netherlands and their homeland, migrants who travel to their homeland might form a bridge population for HIV and sexually transmitted infection (STI) transmission. We studied the determinants for such a population in two large migrant communities in The Netherlands. METHODS: From 2003 to 2005, 1938 people of Surinamese and Antillean origin were recruited at social venues in two large cities, interviewed and their saliva samples tested for HIV antibodies. We used multivariate multinomial logistic regression to explore characteristics of groups with four risk levels (no, low, moderate and high) for cross-border transmission. RESULTS: 1159/1938 (60%) participants had travelled from The Netherlands to their homeland in the previous 5 years and 1092 (94%) of them reported partnerships and condom use in both countries. Of these 9.2% reported having unprotected sex with partners in both countries. People in this high-risk or bridge population group were more likely to be male, frequent travellers and older compared with people who had no sex or had sexual contact solely in one country in the past 5 years. CONCLUSIONS: Older male travellers of Surinamese and Antillean origin are at high risk for cross-border heterosexual transmission of HIV/STIs. They should be targeted by prevention programmes, which are focused on sexual health education and HIV/STI testing, to raise their risk awareness and prevent transmission.

Evaluation prompting transition from enhanced to routine surveillance of lymphogranuloma venereum (LGV) in the Netherlands.

In 2004, a lymphogranuloma venereum (LGV) epidemic among men who have sex with men in the Netherlands motivated the introduction of enhanced surveillance. We evaluated the acceptability of the enhanced LGV surveillance in the Netherlands in 2004-2005 to provide recommendations for future surveillance. Completeness of requested patient information was analysed. All 12 sexually transmitted infection (STI) health services participating in the 2004-2005 STI surveillance completed evaluation questionnaires and rated surveillance system features from 1="very poor" to 5="very good". Information from enhanced LGV surveillance was available for 34 (33%) of 104 cases. For these 34 cases, median proportions of response decreased successively for clinical information (100%), sexual anamnesis (71%) and details about the last sex partners (44%). A median score of 4 ("good") was assigned to simplicity, required resources and surveillance information requested and distributed. Seven respondents favoured continuation of LGV surveillance, whereof six preferred modifications, usually meaning less extensive surveillance. In conclusion, the enhanced LGV surveillance was generally regarded as adequate. However, it was limited by low completeness, underlining the need to keep requested information to a minimum. The routine STI surveillance now includes LGV diagnosis and, following this evaluation, the additional enhanced surveillance was discontinued. However, occasional cases justify alertness and LGV remains under routine STI surveillance in the Netherlands.

[Hepatitis B virus transmission patterns in the Netherlands, 2004]. / Transmissiepatronen van hepatitis B-virus in Nederland, 2004.

OBJECTIVE: To gain insight into hepatitis B virus (HBV) transmission in the Netherlands. DESIGN: Descriptive. METHOD: During 2004, epidemiological data and blood samples (if available) were collected for all reported cases of acute HBV infections in the Netherlands. Following DNA isolation and amplification a 648 base pairs fragment of the HBV S gene was sequenced and subjected to phylogenetic analysis. The sequencing details were also linked to epidemiological information. RESULTS: In 2004, 291 cases ofacute HBV infections were reported. Blood samples were received from 171 patients (59%), and the genotype could be determined for 158 patients (54%). 6 genotypes were identified: A (64%), B (3%), C (3%), D (21%), E (5%) and F (4%). Of all patients with genotype A, 52% had been infected via homosexual or bisexual contact and 16% via heterosexual contact. Of all patients with genotype D, 42% had been infected via heterosexual contact and 15% via homosexual or bisexual contact. The genotype A cluster was extremely homogeneous with many identical sequences, while genotype B-E clusters were more heterogeneous. 4 identical sequences were found within genotype F, but the patients could not be epidemiologically linked. CONCLUSION: Sexual transmission, particularly via homosexual or bisexual contact in men, formed the most important risk factor for acquiring an acute HBV infection. Genotype A was predominant in the Netherlands, especially among homosexual or bisexual men. Most infections within genotype D occurred as a result of heterosexual contact. The results show that there was ongoing transmission of HBV in homosexual or bisexual men, while in heterosexuals more cases of new introduction were seen, possibly via chronic carriers from areas where HBV is endemic.

Hepatitis B virus transmission in The Netherlands: a population-based, hierarchical case-control study in a very low-incidence country.

We report the first population-based case-control study on acute hepatitis B in a very low-incidence country. A case was a Netherlands resident, notified between May 1999 and July 2000 with symptoms and serology compatible with acute hepatitis B. Population controls were randomly selected, with oversampling from men and persons aged 20-39 years. Risk factors were studied using logistical regression, distinguishing confounders and mediators through hierarchical analysis. Participants were 120 cases and 3948 controls. The risk of acute hepatitis B was increased in men who have sex with men, with reporting to have had more than two partners in the past 6 months the only significant risk. In children, adult females and heterosexual males, having parents born in a hepatitis B endemic country was a significant risk. For adult females and heterosexual males, this was largely explained by having a foreign partner. For children this was partly explained by parenteral exposures abroad.

Results of a Europe-wide investigation to assess the presence of a new variant of Chlamydia trachomatis.

In 2006, a new variant of Chlamydia trachomatis was reported in Sweden. Three countries - Ireland, Norway, and Denmark - have detected the variant to date, but very few cases in total have occurred. The European network for STI surveillance (ESSTI) and the European Centre for Disease Prevention and Control (ECDC) assessed the potential spread of the variant in other European countries, and concluded that there is currently no evidence that the variant has spread widely across Europe. However, the variant strain has been reported in between 10% and 65% of infected patients in Sweden. It is too early to tell whether the variant will remain confined to Sweden or whether the number of cases will significantly increase. Enhanced surveillance will need to be continued to address these concerns.

[Hepatitis B surveillance in the Netherlands, 2002-2005: acute infection is mainly via sexual contact while chronic infection is via vertical transmission through mothers from endemic regions]. / Surveillance van hepatitis B in Nederland, 2002-2005: acute infectie vooral via seksueel contact, chronische via verticale transmissie door moeders uit endemische gebieden.

OBJECTIVE: To study the trends in the prevalence of hepatitis B infections in the Netherlands on the basis of reported cases. DESIGN: Retrospective, descriptive. METHOD: Analysis of data collected from the obligatory notification of hepatitis B to the Dutch Public Health Services in the Netherlands in the period 2002-2005. RESULTS: In the period from January 2002 to December 2005, 7352 hepatitis B virus (HBV) infections were reported, of which 1168 (16%) were acute and 5849 (80%) were chronic infections. Of the acute HBV infections, 34% were transmitted by homo- or bisexual contact and 25% by heterosexual contact. The number of reports of acute HBV infection due to heterosexual transmission increased significantly and originated relatively more often in Dutch patients. The number of reports of chronic HBV infection in men increased significantly; in women there was a decrease over time. Of the chronic HBV infections, 40% were transmitted from mother to child; this was reported especially often by patients from HBV endemic areas. CONCLUSION: Sexual contact was the most important risk factor for the transmission of acute HBV infections, whereas vertical transmission was the greatest risk factor by far for chronic HBV infection. Transmission via heterosexual contact had become increasingly important in the transmission of acute HBV; transmission by homo- or bisexual contact remained constant. Immigration continued to play an important role in the epidemiology of HBV in the Netherlands; the majority of the chronic carriers had been born and infected in an HBV endemic area.

Molecular epidemiology of acute hepatitis B in the Netherlands in 2004: nationwide survey.

To gain insight into hepatitis B virus (HBV) transmission in the Netherlands, epidemiological data and sera were collected from reported cases of acute HBV infections in the Netherlands in 2004. Cases were classified according to mode of transmission. A fragment of the S-gene of HBV (648 bp) was amplified, sequenced, and subjected to phylogenetic analysis. Of the 291 acute HBV cases reported in 2004, 158 (54%) were available for genotyping. Phylogenetic analysis identified 6 genotypes: A (64%), B (3%), C (3%), D (21%), E (5%) and F (5%). Of HBV infected men having sex with men, 86% were infected with genotype A, accounting for 43% of all patients infected with this genotype. There were only three reported cases of injecting drug use of which one was available for sequencing (genotype A). Unlike the genotype A cluster, sequences within the genotype B-E clusters were heterogenic. Within genotype F, several isolates had identical sequences, but patients could not be epidemiologically linked. Sexual transmission, particularly by men having sex with men was the most important transmission route for HBV. Injecting drug use plays a minor role. Genotype A is predominant in the Netherlands, especially among men having sex with men. In addition to imported strains, there seems to be a pool of related but non-identical strains circulating among chronic carriers in the migrant population, from which occasionally new patients are infected, primarily by heterosexual transmission.

[Further increase of quinolone resistance of gonococci in the Netherlands and proposal for a new surveillance]. / Verdere toename in chinolonresistentie van gonokokken in Nederland en voorstel voor hernieuwde surveillance.

Previous publications have indicated that between 2002 and 2003 in the Netherlands, the antimicrobial resistance in gonococci increased. Repeat measurements in 2004 and 2005 suggest a further increase in resistance ofgonococci, to quinolones in particular, from 7% in 2002 to 26% in 2005. National surveillance of gonococcal antimicrobial resistance is important for public health. In 2006 a further survey will be implemented, in which resistance data and epidemiological information on the patients are combined and collected in a project called 'Gonococcal resistance to antimicrobials surveillance' (GRAS).

A slow epidemic of LGV in the Netherlands in 2004 and 2005.

In 2004, an outbreak of LGV was detected in MSM in the Netherlands. By January 2006, 179 confirmed cases of LGV had been reported; 65 (retrospectively) in 2002/2003, 76 in 2004 and 38 in 2005. The evolution of the LGV outbreak appears to have slowed down and only a few cases were found in the first months of 2006.

HIV and STIs increasing in the Netherlands according to latest surveillance data.

In 2004, numbers of sexually transmitted infections (STIs) increased in the Netherlands compared with 2003.

A slow epidemic of LGV in the Netherlands in 2004 and 2005.

In 2004, an outbreak of LGV was detected in MSM in the Netherlands. By January 2006, 179 confirmed cases of LGV had been reported; 65 (retrospectively) in 2002/2003, 76 in 2004 and 38 in 2005. The evolution of the LGV outbreak appears to have slowed down and only a few cases were found in the first months of 2006.

[Resistance of gonococci in the Netherlands; results of a survey of medical microbiology laboratories]. / Resistentie van gonokokken in Nederland; resultaten van een enquête bij medisch-microbiologische laboratoria.

OBJECTIVE: To collect information about the incidence ofgonorrhoea and gonococcal resistance in the Netherlands. METHOD: A questionnaire was sent to 39 medical microbiology laboratories to obtain information on current diagnostics and the susceptibility testing method, and on the number of positive results and the susceptibility pattern of gonococcal isolates in 2002 and 2003 (up to and including November). RESULTS: 32 laboratories participated in this survey. 13 laboratories used culture alone and 19 laboratories used culture and/or a molecular test. Gonorrhoea was diagnosed 2,666 times in 2002 and 2,190 times in 2003, with an incidence of 33.5 and 27.0 per 100,000 inhabitants, respectively. The rate of resistance to beta-lactam antibiotics (penicillin and amoxicillin) was 12.2% and 10.7% in 2002 and 2003, respectively, and the rates of resistance to tetracycline were 18.5% and 20.6%. An increase in the resistance to quinolones was observed from 6.6% in 2002 to 9.5% in 2003. Resistance to cephalosporins was low (0.5% in 2002 and 1.2% in 2003). Furthermore, regional differences in susceptibility were found within the Netherlands. CONCLUSION: The observed gonococcal incidence and resistance form the basis for a gonorrhoea prevention and treatment programme in the Netherlands.

The importance of imported infections in maintaining hepatitis B in The Netherlands.

In The Netherlands, in May 1999 an enhanced surveillance of hepatitis B was begun to collect detailed information of patients with acute hepatitis B virus (HBV) infection. The objective was to gain insight in transmission routes and source of infection of new HBV cases. Through public health services, patients were interviewed on risk factors. It appeared that the majority (59%) acquired the infection through sexual contact; 52% of these by homosexual and 48% by heterosexual contact. In 60% of the heterosexual cases, the source of infection was a partner originating from a hepatitis B-endemic region. Sexual transmission is the most common route of transmission of acute hepatitis B in The Netherlands and introduction of infections from abroad plays a key role in the current epidemiology of HBV. As well as prevention programmes targeted at sexual high-risk groups, prevention efforts should focus more on the heterosexual transmission from HBV carriers.