M van Veen

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.

Hepatitis C virus prevalence in The Netherlands: migrants account for most infections

A population-based anti-hepatitis C virus (HCV) prevalence is important for surveillance purposes and it provides insight into the burden of disease. The outcomes of recent studies in the general Dutch population as well as recent HCV data from specific risk groups including migrants, men who have sex with men (MSM) and injecting drug users (IDUs), were implemented in a modified version of the Workbook Method (a spreadsheet originally designed for HIV estimations), to estimate Dutch HCV seroprevalence. The estimated national seroprevalence of HCV was 0·22% (min 0·07%, max 0·37%), corresponding to 28 100 (min n = 9600, max n = 48 000) HCV-infected individuals in The Netherlands. Of these, first-generation migrants from HCV-endemic countries (HCV prevalence ≥2%) accounted for the largest HCV-infected group, followed by IDUs and HIV-positive MSM.

Disassortative Sexual Mixing among Migrant Populations in the Netherlands: a Potential for HIV/STI Transmission?

Abstract 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.

Increasing trend in gonococcal resistance to ciprofloxacin in The Netherlands, 2006–8

Introduction Rapid development of Neisseria gonorrhoeae resistance to several antibiotics in recent years threatens treatment and prevention. Targeted surveillance of new resistance patterns and insight into networks and determinants are essential to control this trend. Methods Since the Gonococcal Resistance to Antimicrobials Surveillance (GRAS) project was implemented within the Dutch national sexually transmitted infection (STI) surveillance network in July 2006, participating STI centres have collected a culture from each gonorrhoea patient. Isolates were tested for susceptibility to penicillin, tetracycline, ciprofloxacin and cefotaxime using Etest. Logistic regression was used to determine risk factors for ciprofloxacin resistance. Results Between July 2006 and July 2008, prevalence of resistance to penicillin was 10%, to tetracycline 22% and to ciprofloxacin 42%. Resistance to cefotaxime was not found, although minimum inhibitory concentrations higher than 0.125 mg/l drifted upward (p<0.05). Ciprofloxacin resistance rose from 35% in 2006 to 46% in 2008 (p<0.05), despite 2003 guidelines naming cefotaxime as first-choice therapy. In men, ciprofloxacin resistance was higher in men having sex with men (MSM) than in heterosexual men (adjusted OR 2.0, 95% CI : 1.5 to 2.6). In women, it was higher in commercial sex workers (adjusted OR 25.0, 95% CI 7.7 to 78.2) and women aged over 35 years (adjusted OR 8.2, 95% CI 3.0 to 22.7) than in other women. Conclusion Ciprofloxacin resistance in The Netherlands is increasing, and is particularly found in MSM, older women, and female sex workers. No resistance to current first-choice therapy was found, but alertness to potential clinical failures is essential. By merging epidemiological and microbiological data in GRAS, specific high-risk transmission groups can be identified and policy adjusted when needed.

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.

Delayed linkage to care in one-third of HIV-positive individuals in the Netherlands

Objectives To determine time to linkage to HIV care following diagnosis and to identify risk factors for delayed linkage. Methods Patients newly diagnosed with HIV at sexually transmitted infections (STI) clinics in the Netherlands were followed until linkage to care. Data were collected at the time of diagnosis and at first consultation in care, including demographics, behavioural information, CD4+ counts and HIV viral load (VL) measurements. Delayed linkage to care was defined as >4 weeks between HIV diagnosis and first consultation. Results 310 participants were included; the majority (90%) being men who have sex with men (MSM). For 259 participants (84%), a date of first consultation in care was known; median time to linkage was 9 days (range 0–435). Overall, 95 (31%) of the participants were not linked within 4 weeks of diagnosis; among them, 44 were linked late, and 51 were not linked at all by the end of study follow-up. Being young (<25 years), having non-Western ethnicity or lacking health insurance were independently associated with delayed linkage to care as well as being referred to care indirectly. Baseline CD4+ count, VL, perceived social support and stigma at diagnosis were not associated with delayed linkage. Risk behaviour and CD4+ counts declined between diagnosis and linkage to care. Conclusions Although most newly diagnosed patients with HIV were linked to care within 4 weeks, delay was observed for one-third, with over half of them not yet linked at the end of follow-up. Vulnerable subpopulations (young, uninsured, ethnic minority) were at risk for delayed linkage. Testing those at risk is not sufficient, timely linkage to care needs to be better assured as well.

Neurosyphilis in the mixed urban–rural community of the Netherlands

Objective Neurosyphilis is caused by dissemination into the central nervous system of Treponema pallidum. Although the incidence of syphilis in the Netherlands has declined since the mid-1980s, syphilis has re-emerged, mainly in the urban centres. It is not known whether this also holds true for neurosyphilis. Methods The epidemiology of neurosyphilis in Dutch general hospitals in the period 1999–2010 was studied in a retrospective cohort study. Data from the Dutch sexually transmitted infection (STI) clinics were used to analyse the number of patients diagnosed with syphilis in this period. Results An incidence of neurosyphilis of 0.47 per 100 000 adults was calculated, corresponding with about 60 new cases per year. This incidence was higher in the western (urbanised) part of the Netherlands, as compared with the more rural areas (0.6 and 0.4, respectively). The number of patients diagnosed with syphilis in STI clinics increased from 150 to 700 cases in 2004 and decreased to 500 new cases in 2010. The sex ratio was in favour of men, yielding a percentage of 90% of the syphilis cases and of 75% of the neurosyphilitic cases. The incidence of neurosyphilis was highest in men aged 35–65 years, and in women aged 75 years and above. The most frequently reported clinical manifestation of neurosyphilis was tabes dorsalis. In this study, 15% of the patients were HIV seropositive. Conclusion The incidence of neurosyphilis in a mixed urban–rural community such as the Netherlands is comparable to that in other European countries. Most patients are young, urban and men, and given the frequent atypical manifestations of the disease reintroduction of screening for neurosyphilis has to be considered.

Ethnic and regional differences in STI clinic use: a Dutch epidemiological study using aggregated STI clinic data combined with population numbers

Objectives Ethnic minorities (EM) from STI-endemic countries are at increased risk to acquire an STI. The objectives of this study were to investigate the difference in STI clinic consultation and positivity rates between ethnic groups, and compare findings between Dutch cities. Methods Aggregated population numbers from 2011 to 2013 of 15–44 year-old citizens of Amsterdam, Rotterdam, The Hague and Utrecht extracted from the population register (N=3 129 941 person-years) were combined with aggregated STI clinic consultation data in these cities from the national STI surveillance database (N=113 536). Using negative binomial regression analyses (adjusted for age and gender), we compared STI consultation and positivity rates between ethnic groups and cities. Results Compared with ethnic Dutch (consultation rate: 40.3/1000 person-years), EM from Eastern Europe, Sub-Sahara Africa, Suriname, the Netherlands Antilles/Aruba and Latin America had higher consultation rates (range relative risk (RR): 1.27–2.26), whereas EM from Turkey, North Africa, Asia and Western countries had lower consultation rates (range RR: 0.29–0.82). Of the consultations among ethnic Dutch, 12.2% was STI positive. Positivity rates were higher among all EM groups (range RR: 1.14–1.81). Consultation rates were highest in Amsterdam and lowest in Utrecht independent of ethnic background (range RR Amsterdam vs Utrecht: 4.30–10.30). Positivity rates differed less between cities. Conclusions There were substantial differences in STI clinic use between ethnic groups and cities in the Netherlands. Although higher positivity rates among EM suggest that these high-risk individuals reach STI clinics, it remains unknown whether their reach is optimal. Special attention should be given to EM with comparatively low consultation rates.

O09.5 Optimizing Care Efficiency at the STI Clinic: Using Chlamydia Home Collection Kits

Background To study the efficiency of Chlamydia home collection kits for young people, in order to optimise care at the Amsterdam STI clinic. Methods Since 2012, young people under the age of 25 with a low risk profile for STIs are only tested for Chlamydia. Tests for other STIs are indicated after testing Chlamydia positive. From September-November 2012, young people using the online intake were offered two different ways of Chlamydia testing: receiving a home collection kit, or coming to the clinic. The collection kit is send to the client by mail and is used to collect a swab or urine sample. This sample is send back to the laboratory for testing. The client can retrieve the results online by using the provided login. Results In the study period, 523 online requests were done. Of these, 388 (74%) opted for the home collection kit and 135 (26%) preferred an appointment at the clinic. Of the requested kits, 86% were send back. All clients checked their test result online. Chlamydia was diagnosed in 5.5% of the clients receiving a home kit and in 2.9% of those tested at the clinic. Women were more likely to request a home collection kit (77% versus 60% of men, p < 0.001) as were young people aged 20–24 years (76% versus 64% aged < 20 years, p < 0.05). None of the Chlamydia-positive clients tested positive on the subsequent STI tests. Testing at the clinic takes three times more time of the nurse. Conclusions Young people prefer a home collection kit to a test at the clinic. Furthermore, offering home collection kits is time and cost saving. Because clients who test negative are not seen at the clinic, more time is left for high-risk groups. In conclusion, Chlamydia home collection kits optimise care efficiency at the STI clinic.

P3.129 Identifying Recently Acquired HIV Infections Among Newly Diagnosed Men Who Have Sex with Men in the Netherlands

Background The number of newly diagnosed HIV infections among men who have sex with men (MSM) has gradually increased in the Netherlands during the past decade. However, the current HIV surveillance system cannot differentiate recent HIV infections from longstanding HIV infections. We determined the proportion of recent HIV infections (RI) and estimated HIV incidence using Recent Infection Testing Algorithm (RITA) among newly diagnosed HIV infections among MSM in Amsterdam and Rotterdam. Methods Plasma samples (n = 251) collected from newly HIV-diagnosed MSM during 2009–2011 at the STI clinics in Amsterdam and Rotterdam were analysed in the study. To test for recent infections, anti-HIV avidity index (AI) was measured in plasma with Architect HIV Ag/Ab Combo immunoassay. Samples were classified as recent if the AI was ≤ 0.80. Data on viral load, CD4 count and previous HIV testing were incorporated in the RITA algorithm to minimise false recent infections. HIV incidence and 95% confidence intervals (CI) were estimated using previously described methods. Results Of the 251 samples from MSM, 83 were classified as recent by the avidity index. Five cases were reclassified as non-recent based on low CD4 count (n = 2) and viral load (n = 2) and history of HIV infection (n = 1) and thus, 78/251 (31%) infections were determined as recent on RITA. Proportions of RIs in 2009, 2010 and 2011 were 32%, 28% and 33%, respectively. The estimate for combined incidence was 1.5% per year (95% CI 1.17–1.83). No significant changes over time were observed. Conclusions This study estimated the proportion of RIs and HIV incidence among MSM in the Netherlands using the RITA algorithm for the first time. The proportion of RIs was comparable to similar studies in other European countries such as the UK, which however used different methodology.