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.

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.

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.

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.

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.

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.

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.

[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).

[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.

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.

Upsurge of hepatitis A in the Netherlands - early 1998.

Far more cases of hepatitis A were identified in the Netherlands in the first five months of 1998 than in the same period of 1997. In order to investigate the reasons for this upsurge we compared the notified cases of hepatitis A in the first five months

[HIV prevalence among injecting drug users in South Limburg, 1994-1998/1999: increasing trend in Heerlen, not in Maastricht]. / HIV-prevalentie onder injecterende druggebruikers in Zuid-Limburg, 1994-1998/'99: stijgende trend in Heerlen, niet in Masstricht.

OBJECTIVE: To determine the prevalence of HIV infection and gain insights into the risk behaviour among injecting drug users (IDU) in Heerlen and Maastricht, the Netherlands. DESIGN: Descriptive inventory. METHOD: In 1994, 1996 and 1998/1999 a questionnaire on risk behaviour was obtained from 866 IDUs in Heerlen and Maastricht, and 858 saliva and serum samples were also obtained for testing on HIV antibodies. RESULTS: In the total region of Heerlen and Maastricht, no significant change in HIV prevalence was found (1994: 10%, 1996: 12%, 1998/1999: 14%). However, in Heerlen the HIV prevalence was demonstrated to have increased significantly (1994: 11%, 1996: 16%, 1998/1999: 22%), whereas in Maastricht HIV prevalence was constant (1998/1999: 5%). The percentage of participants that injected drugs in the six months preceding the survey decreased from 80% in 1994 to 63% in 1998/1999. Injection-related risk behaviour slightly decreased: in 1998/1999 14% of the participants had borrowed used syringes or needles in the last 6 months. Additionally, inconsistent condom use with steady and casual sexual partners was reported. Of the participants, 86-89% did not always use condoms with steady partners and 49% with casual partners. DISCUSSION: In view of the increasing HIV prevalence among IDUs in Heerlen, the persistent injecting and sexual risk behaviour and the large number of IDUs who have sexual contact with non-users in Heerlen and Maastricht, there is a substantial risk of HIV transmission both within the IDU community and to the general population.

[Trends in HIV prevalence and risk behaviour among injecting drug users in Rotterdam, I994-2002]. / Trends in HIV-prevalentie en risicogedrag onder injecterende druggebruikers in Rotterdam, 1994-2002.

OBJECTIVE: To gain insight into the prevalence of HIV infection, the determinants thereof and the risk behaviour in injecting drug users (IDUs) in Rotterdam, The Netherlands, in 2002 in comparison to the HIV survey data from 1994 and 1997. DESIGN: Questionnaire study. METHOD: In 1994-2002, three periodic HIV surveys were conducted in Rotterdam among IDUs using semi-structured questionnaires on risk behaviour and saliva samples for HIV-antibody determination. In the present study, the data for 2002 were analysed and compared with those from 1994 and 1997. RESULTS: The number of participants recruited was 494, 470 and 452, respectively. HIV prevalence did not change over time: 1994: 11.4%, 1997: 9.4% and 2002: 10.2%. In the 2002 survey, independent risk factors for HIV were homelessness and onset of injecting drug use at an early age. The percentage of IDUs that had recently shared needles declined from 18% in 1994 to 8% in 2002. Risky sexual behaviour remained prevalent: inconsistent condom use was reported by 85% with steady partners, 43% with casual partners and 31% with clients. The IDUs who knew that they were HIV positive used condoms consistently more often. CONCLUSION: The combination of a relatively high HIV prevalence among IDUs in Rotterdam and the high level of unsafe sexual behaviour results in a serious risk of further spread of HIV among both IDUs and the general population.

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.