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.

SARS knowledge, perceptions, and behaviors: a comparison between Finns and the Dutch during the SARS outbreak in 2003.

BACKGROUND: The SARS outbreak served to test both local and international outbreak management and risk communication practices. PURPOSE: The study compares SARS knowledge, perceptions, behaviors, and information between Finns and the Dutch during the SARS outbreak in 2003. METHOD: The participants of the study, who used a modified SARS Psychosocial Research Consortium survey, were drawn from Internet panels in Finland (n = 308) and the Netherlands (n = 373) in June 2003. Multiple logistic regression analyses were used to calculate odds ratios (with 95% confidence intervals) to compare Finns with the Dutch for various levels of perceptions and behaviors. RESULTS: Adjusted for age, education, and income, Finns were more likely to be knowledgeable and worried about SARS as well as to have low perceived comparative SARS risk and poor personal efficacy beliefs about preventing SARS. Finns were also more likely than the Dutch to have high confidence in physicians on SARS issues but less likely to have received information from the Internet and have confidence in Internet information. CONCLUSIONS: The study shed light on how two European populations differed substantially regarding lay responses to SARS. Understanding these differences is needed in formulating and executing communication and outbreak management.

A cluster of hepatitis B infections associated with incorrect use of a capillary blood sampling device in a nursing home in the Netherlands, 2007.

In July 2007, two residents of a nursing home were diagnosed with acute Hepatitis B virus infection. To identify risk factors for HBV infection a retrospective cohort study among residents was performed. Case finding included discharged diabetes patients and those receiving home care. Among 32 residents one case of chronic hepatitis B was found that could be identified by genotyping as the source patient for the acute cases. Diabetes and finger sticks were risk factors for HBV infection. Most likely the cause of transmission was a multiclix finger stick device developed for use in individual patients but used in multiple patients. Education and training in the use of new equipment and hygiene audits remain the cornerstones in infection control practices.

Social-cognitive determinants of HIV risk-taking intentions among men who date men through the Internet.

The present study was set up to investigate social-cognitive determinants of HIV-risk precautionary intentions among men who have sex with men (MSM), who meet sex partners on the Internet. Participants were enrolled through the major gay chat room in The Netherlands, www.chatboy.nl, and were asked to complete an online questionnaire. Theory of Planned Behaviour variables attitude, subjective norm, and perceived control explained 55% of the variance in intention to use condoms for anal sex with future e-dates. Adding descriptive norm, personal norm and anticipated regret explained 70%. Sexual fantasies and HIV-status had unique effects on intentions. Differences between high and lower intenders are presented. Limitations of the study are discussed and objectives for an intervention to promote condom use are given.

Chlamydia trachomatis infections in multi-ethnic urban youth: a pilot combining STI health education and outreach testing in Rotterdam, Netherlands.

BACKGROUND/OBJECTIVES: Testing for Chlamydia trachomatis (Ct) is less accepted in people of non-Dutch ethnicity than Dutch people. We offered additional Ct and gonorrhoea testing through our outreach sexually transmitted infections (STI) prevention programme to determine whether this intervention strategy is feasible and efficient. METHODS: Outreach workers offered test kits to women and men aged 15-29 years, in group and street settings and in a vocational training school. Demographic and behavioural data and characteristics of non-responders were assessed. DNA was isolated (using the MagNA Pure LC system) from urine and tested using the Cobas Amplicor test. RESULTS: Among sexually active people, the test rate differed by venue (groups 80% (74/93), school 73% (49/67), street 17% (49/287); p<0.001). There was no difference in test rate between group and school settings by gender or ethnicity. Ct positivity was 14.5% (25/172); women 20.2% (20/99) versus men 6.8% (5/73); p = 0.01. Ct positivity was highest at school (24.5% (12/49)) and among Surinamese/Antillean people (17.5% (14/80)). Treatment rate of index cases and current partners was 100% and 78%, respectively. CONCLUSIONS: We found a high acceptance of chlamydia testing in group and school settings in both men and women of non-Dutch ethnicity. The prevalence indicates that we have accessed high risk people. Outreach testing and is feasible and most efficient in school and group settings. School screening may have an impact on community prevalence of Ct infections.

An outbreak of hepatitis A among homeless drug users in Rotterdam, The Netherlands.

From the end of January to mid-June 2004 (weeks 5-24) a hepatitis A virus (HAV) outbreak occurred among a homeless and drug user community in Rotterdam, The Netherlands. To prevent further spread of the virus within this group and to the general population, the Municipal Health Service of Rotterdam organized a mass vaccination campaign during which 83% (1,515/1,800) of the homeless people were vaccinated. As part of a national HAV typing study, blood and/or fecal samples of 30 Rotterdam HAV IgM+ patients who fell ill during the period of 1 September 2003-1 December 2004 were tested. The tests included RT-PCR and sequencing at the VP3-VP1 and VP1-P2a regions of the HAV genome. It was found that 12 homeless people, one family member of a homeless person and two people without a known risk were infected with a unique subtype 3a strain. Four of the homeless patients became ill after vaccination and were probably infected at the time. This study shows that Dutch homeless people and drug users involved in HAV outbreaks should be offered HAV vaccine actively to prevent further spread of the infection. Furthermore, it was shown by molecular techniques that the unique subtype 3a strain was not found before the Rotterdam outbreak or afterwards, indicating that the mass vaccination campaign was successful.

[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.

[A cluster of lymphogranuloma venereum among homosexual men in Rotterdam with implications for other countries in Western Europe]. / Cluster van lymphogranuloma venereum onder homoseksuele mannen in Rotterdam, met grensoverschrijdende gevolgen.

In mid-December 2003, a cluster of 15 cases of lymphogranuloma venereum (LGV) among male homosexuals was reported to the Municipal Health Service in Rotterdam by the Erasmus Medical Centre's outpatient clinic for sexually transmitted infections (STI). Most patients presented with proctitis and some with constipation. All were Caucasian and between 26 and 48 years of age. Thirteen of them were HIV-positive and eight had a concomitant STI. All men reported having had unprotected insertive and receptive anal sexual contact. Many sexual contacts were anonymous and were reported to have taken place in Germany, Belgium, the United Kingdom and France. This outbreak of LGV may extend through a large part of western Europe. In view of the patients' international contacts, international warnings and alertness are needed. Concerted action of professionals in infectious disease control and curative care is called for.

[Increase of early syphilis in a red light district in Rotterdam (1995-1997) and preventive treatment]. / Toename van vroege syfilis in een tippelzone in Rotterdam (1995-1997) en profylactische behandeling.

The number of cases of syphilis in Rotterdam has increased dramatically since 1995. The prevalence of early syphilis in 1997 was highest among street prostitutes (16%). Some prostitutes could not be reached for further evaluation and treatment, probably due to their addiction to hard drugs. Prophylactic treatment for syphilis was given to most street prostitutes in a cruising zone during a screening programme for sexually transmitted diseases (STD) in January 1997. Since then, STD checkups were performed regularly in the cruising zone. The prevalence of early syphilis in the cruising zone dropped to 1.3% in 1998. The total number of reported cases of syphilis in Rotterdam also decreased sharply in 1998.

[Screening policy for travellers from Rotterdam for hepatitis A antibodies prior to eventual immunization: favourable cost-benefit ratio]. / Beleid bij screening van reizigers uit Rotterdam op antistoffen tegen hepatitis A voorafgaand aan eventuele immunisatie: gunstige kosten-batenverhouding.

OBJECTIVE: To evaluate costs and benefits of the screening and immunisation policy for hepatitis A virus (HAV) infection among travellers from Rotterdam. DESIGN: Descriptive and cost-benefit analysis. METHOD: From the data of the Municipal Health Service Rotterdam (GGD), the Netherlands, the details were collected on individuals travelling frequently to HAV endemic countries, who were born before 1950, or had lived for more than 10 years in an HAV endemic country or had ever suffered jaundice. Persons to whom these criteria applied were screened for HAV antibodies at the GGD before immunisation for HAV in the period January 1st 1996-June 30th 1998. Screening and vaccination policies were compared with a cost analysis. RESULTS: Antibodies against HAV were found in 79% of 1466 screened people. The lowest prevalence of antibodies was found among Dutch nationals (67%). A significantly higher prevalence was found amongst individuals from Turkey/Morocco (96%) and from the Cape-Verde Islands (97%). In the cost analysis the break even point, the prevalence level of HAV antibodies in the population at which screening cost as much as blind prophylaxis, lay for passive immunisation between 69% and 93%. For active immunisation this point lay around 17%. CONCLUSION: The selection criteria for prevaccination screening are effective in identifying individuals with a high probability of being immune against HAV infections. The current screening policy for antibodies against HAV is cost effective.

Outbreak of hepatitis A in Rotterdam associated with visits to 'darkrooms' in gay bars.

An unexpectedly large number of hepatitis A virus (HAV) infections were notified among homosexual men in Rotterdam in the first five months of 1998. A case control study was conducted to investigate the hypothesis that this outbreak was associated with sexual practices and to collect information with which to focus preventive activities. Notified cases and controls selected from male members of a gay sports club completed anonymous questionnaires about known risk factors for HAV infection and sexual behaviour. Single variable analysis showed that HAV infection was associated with sexual contact with anonymous sex partners (odds ratio (OR) 4.6; 95% confidence interval (CI) 1.0-23.2) and with visits to 'darkrooms' in gay bars (OR 6.2; 95% CI 1.5-26.8). A negative association with travel abroad to western countries was observed (OR 0.4; 95% CI 0.1-1.3). The associations with visits to darkrooms (OR = 9.2; 95% CI 1.6-52.4) and travel abroad to western countries (OR 0.1; 95% CI 0.02-0.9) remained significant in a multivariable logistic regression analysis. This risk group was targeted for health education and vaccination and darkroom owners were advised to provide hygiene facilities.