In this study the level of HIV infection among injecting drug users (IDU) in Rotterdam (Netherlands) is assessed. The results were compared with a previous survey in Rotterdam in 1994. The risk of further spread of HIV is evaluated. Between March 4 and May 15 1997 a saliva specimen and a questionnaire on risk behaviour were obtained from 470 IDU in Rotterdam. Of 468 IDU, 44 persons were infected. Seroprevalence was not significantly different from the previous survey in 1994 (11.4%). Independent risk factors for a positive test result were imprisonment, borrowing used syringes or needles, using condoms with steady partners and taking an HIV test in the past. The prevalence of HIV among IDU in Rotterdam in the Netherlands proved to be 9.4%, similar to the level in 1994. Injecting risk behaviour occurs at a lower level then in 1994. Sexual risk behaviour occurs frequently. The risk of further spread among IDU is high and spread of HIV to non-IDU or the general population, especially steady partners of IDUs, is likely.

In the Netherlands an electronic network has been proposed for structured data transfer and communication concerning the control of infectious diseases. This project has been baptized ISIS (Infectious diseases Surveillance Information System). It is an initiative of the Dutch Government. ISIS will be developed, implemented and exploited by the Department of Infectious Diseases Epidemiology (CIE) of the National Institute of Public Health and Environmental Protection (RIVM). Objectives for ISIS: 1) To provide the quantitative basis for making decisions about priorities in the control of infectious diseases, i.e. to allow the government to make rational choices about the necessity of developing and implementing control programs, epidemiologic surveys and diagnostic studies. 2). It should be fast and accurate to allow early warning for an outbreak and to facilitate the actual control of an epidemic in the sence that intervention can be focused on the right place and the right subgroup. 3). To facilitate the management of an outbreak in that it provides an efficient infrastructure for communication between participants. At the same time it should monitor the control activities allowing the evaluation of an intervention afterwards. ISIS will replace and extend the current system for the registration of notifiable diseases. The transfer of selected positive and negative findings from a laboratory information computer system will be completely automated. In the end ISIS will encompass all Municipal Health Services (GGD), most Medical Microbiological Laboratories, hospitals, food inspection departments and veterinary information systems. The use of current standards for data-communication allows nationwide and international collaboration and data-exchange.<br>

In this study the levels of HIV infection is assessed among injecting drug users (IDUs), and drug users of Surinamese/Antillian origin (SUR/ANT) in Amsterdam, the Netherlands. The risk of further spread within both groups and to the general populationis is evaluated. Between 22 May and 17 July 1996 a saliva specimen and a short questionnaire on risk behaviour were obtained from 200 IDUs, and 151 SUR/ANT in Amsterdam. IDUs (having injected at least once in the last 6 months) were recruited in the centre of Amsterdam, on the streets (70% ) and at drug-care facilities (30%). Drug users from Surinamese/Antillian origin (about 90% had never injected) were recruited on the street in a South-eastern neighbourhood of Amsterdam. Of the IDUs 51 were infected, among the SUR/ANT three infections were found. Eighteen percent of the IDUs reported borrowing used syringes or needles in the last six months, a figure comparable to that in other cities in the Netherlands. Infections found among IDUs who reported having injected for the first time or having a negative HIV-test since 1991 indicate a limited but ongoing HIV transmission among IDUs. One in nine IDUs had a non-drug user as steady sexual partner. Condom use during sexual contacts between steady partners was low. In conclusion, the prevalence of HIV among IDUs in Amsterdam is about 26%, similar to the level in 1993. The level of infection among SUR/ANT is 2%, not significantly different from 1993. Among IDUs injecting risk behaviour continues to be reported and there are indications for limited but ongoing HIV transmission in this group.<br>

Between October 30 1998 and May 27 1999, a serum sample and a questionnaire on risk behaviour were obtained from 222 IDU in Heerlen and Maastricht. Participation was on a voluntary basis and anonymous. Participants were recruited at methadone treatment sites (63%), low-threshold daytime care projects (19%), 'on the street' (10%), and in detainment sites (7%). Of 214 IDU, 30 persons were found to be infected with HIV (prevalence 14.0%, 95% confidence interval [CI] 9.7 - 19.4). Seroprevalence was higher in Heerlen (21.6%) than in Maastricht (5.1%) and has increased in Heerlen since 1994 (11%). Eighteen (14%) out of 134 currently injecting IDU borrowed syringes or needles in the last 6 months (1996: 17%, 1994: 19%, not significant). These percentages seem to be similar in the other cities in our surveillance studies. Condom use was very low during sexual contact between steady partners; this was found consistently for the total group (89% not always using a condom). 26% of the IDU have a non-drug user as a steady sexual partner. In spite of several prevention programmes, residual injecting and sexual risk behaviour continues. The presence of high risk behaviour in combination with a high HIV-prevalence indicates the risk of further spread of HIV infection

This report reviews the current status with respect to the most important sexually transmitted diseases (STD) from the public health perspective, e.g. gonorrhoea, syphilis, infection with Chlamydia trachomatis, genital infection with the human papilloma virus (HPV), hepatitis B, genital herpes, infection with the human immunodeficiency virus (HIV) and acquired immunodeficiency syndrome (AIDS). The clinical features and microbiological aspects of the sexually transmitted pathogens and the pathogenesis of the diseases are discussed. The transmission and contagiousness of the infections are evaluated with respect to modelling the spread of the diseases and the significance for public health. Furthermore, the currently used diagnostics and the achievements in the field of microbiology are reviewed in relation to their epidemiological qualifications. Next, the various therapeutic possibilities per disease are highlighted. The occurrence of STD in The Netherlands the available data on the incidence and the prevalence of several STD risk factors and figures on morbidity and mortality are discussed and compared to international data. An overview is given of the organisation, financing and current situation of STD control in The Netherlands. Finally, most important developments are highlighted. The incidence of gonorrhoea and syfilis seem to have stabilised in recent years. However, recent increases in gonorrhoea and syphilis were reported by several cities in Europe, including Amsterdam. The current magnitude of the national STD problem in the Netherlands cannot be accurately determined based on present surveillance systems. Due to a revision of the legislation, STD are no longer included in the notification system. For chlamydia there are no national data available. Recently, some prevalence studies were published, indicating high prevalence rates. In 2001 the Health Council will decide on national screening of chlamydia. The data on HPV and herpes in the Netherlands are based on the STD-registration at municipal health services. Results from a population-based seroprevalence study show that 1 out of 12 Dutch inhabitants had serological evidence of a prior genital herpes. The incidence of hepatis B virus infection has stabilised over years. In 2001 the Health Council will advice on the vaccination policy against hepatitis B. Since the introduction of effective antiretroviral therapy, the AIDS registration is regarded to be insufficient to monitor the HIV epidemic. Therefore, HIV registration needs to be considered. In the near future, new surveillance systems for STD and HIV need to be developed. The Ministry of Health will decide on this matter in the spring of 2001.<br>

In this study the prevalence of HIV among intravenous drug users (IDU) in Heerlen and Maastricht (Southern Netherlands) is assessed. The results are compared with a previous survey in Heerlen/Maastricht in 1994. The risk of further spread among IDU, to non-IDU and to the general population is evaluated. The prevalence of HBV and HCV is assessed. Between 7 October and 5 december 1996 a saliva specimen, a blood sample and a short questionnaire on risk behaviour were obtained from 203 IDU in Heerlen and 101 IDU in Maastricht. Of the 304 IDU, 36 persons were infected. Independent risk factors for a positive test result were no fixed abode, imprisonment , current injecting, polydrug use and age under 16 at first injecting (OR=2.8 [1.0-7.8]). 17% of the current injectors borrowed used syringes or needles in the last 6 months, the same level as in 1994. 18% of the IDU have a non-drug user as steady sexual partner. Condom use was low during sexual contact between steady partners. The prevalence of anti-HBV was 63%, HBsAg 6% and anti-HCV 74%. In conclusion the prevalence of HIV among IDU in Southern Limburg is about 12%, simular to the level of 1994 but there is a difference between Heerlen (16%) and Maastricht (3%). Injecting and sexual risk behaviour occurs regularly and at the same level of 1994. The risk of further spread among IDU is high. Spread to non-IDU or the general population, especially steady partners of IDUs, is likely.<br>