[Grounds for the inclusion of vaccination against cervical cancer within the National Immunisation Programme]. / Gronden voor opname van vaccinatie tegen baarmoederhalskanker in het Rijksvaccinatieprogramma.

The recent advice on vaccination against cervical cancer from the Health Council of the Netherlands and the decision by the Minister of Health, Welfare and Sport to implement the vaccination within the National Immunisation Programme by September 2009, has been criticized by a group of authors because five of seven criteria for vaccination in public programmes are considered not to have been met; notably with respect to efficacy and safety. It appears that the available scientific data have been weighted differently by the Health Council committee and the criticising group of authors. In the original advisory report, the committee of the Health Council lists all uncertainties, and argues that a linked monitoring programme will provide public vaccination with sufficient warranties for efficacy and safety. Thus, new opportunities for primary prevention can be taken, and a significant health benefit is likely to be gained. On the other hand, postponing a decision until all uncertainties have been resolved will postpone a significant potential health benefit for many years.

[Vaccines against human papillomavirus (HPV); between registration and implementation]. / Vaccins tegen Humaan papillomavirus (HPV); tussen registratie en implementatie.

--Each year, 600-700 women in the Netherlands are diagnosed with cervical cancer. Over the last 10 years, an average of 250 women have died annually due to cervical cancer. --Gardasil, the first vaccine for Human papillomavirus (HPV), was recently approved in Europe for the prevention of cervical cancer. --The availability of a vaccine for HPV prompts the question whether it should be included in the Dutch National Immunisation Programme. --At the end of 2006, the Medicines Evaluation Board, the Health Council of the Netherlands and the Centre for Infectious Disease Control of the National Institute for Public Health and the Environment organised a workshop for experts in the field to answer that question. --The HPV vaccine provides protection against HPV-16 and HPV-18, which cause approximately 70% of cervical cancers. --Because the efficacy of vaccination is only evident after many years, preserving good participation in the screening programme is essential. --The current screening could be improved by introducing an HPV test combined with self-sampling for women who do not participate in screening. --Vaccination is unarguably an important development. However, there are still several unanswered questions regarding vaccination and its actual protection, duration of protection, long-term safety and cost-effectiveness. --April 1st, 2008, the Health Council of the Netherlands had recommended including HPV vaccination in the National Immunisation Programme.

[Universal vaccination against group-C meningococci and pneumococci; summary of the advice from the Health Counsil of the Netherlands]. / Algemene vaccinatie tegen meningokokken C en pneumokokken; samenvatting van het advies van de Gezondheidsraad.

The Health Council of the Netherlands (Gezondheidsraad) assessed the vaccination of infants against both group-C meningococci and pneumococci in terms of general criteria and basic principles for inclusion in the national vaccination programme. Vaccination against meningococci C in the Netherlands is expected to prevent about 300 cases of meningococcal disease (meningitis or sepsis), 22 deaths and 12 cases of severe lasting problems (neurological problems or amputations) per year. Vaccination against pneumococci may prevent about 100 cases of meningitis or sepsis, 3200 cases of pneumonia, 36,000 cases of acute otitis media, 11 deaths, 11 cases of severe permanent damage (neurological problems, deafness) per year. The Health Council advised implementing vaccination against group-C meningococci as soon as possible, through 2 injections at the ages of 5 and 6 months or through 1 injection shortly after the child's first birthday, and to carry out a catch-up programme for all children and adolescents up to and including 18 years of age. The council also advised starting a vaccination programme against pneumococci, at ages 2, 3 and 4 months, as soon as the current vaccinations against diphtheria, tetanus, pertussis and polio and against Haemophilus influenzae type b are combined into 1 injection (in 2002 or 2003). In view of the concentration of pneumococci disease in the first years of life, a catch-up programme is not indicated in this case. The Health Council emphasised the importance of microbiological and clinical monitoring of potential adverse effects and of public education programmes. The cost of vaccination against group-C meningococci is comparable to that of other accepted programmes for primary prevention. Compared to other programmes and at the current vaccine price, the cost of vaccination against pneumococci is high.

Back-calculation by birth cohort, incorporating age- specific disease progression, pre-AIDS mortality and change in European AIDS case definition. European Union Concerted Action on Multinational AIDS Scenarios.

OBJECTIVES: To adapt and improve methodology for back-calculation of AIDS in Europe and to examine the feasibility of estimating past HIV incidence by birth cohort. METHODS: Empirical Bayesian back-calculation (EBBC) used Markov disease progression models, modified to allow for three diseases added to the AIDS case definition in 1993 and for pre-AIDS mortality, and estimation by penalized maximum likelihood with a neighbour prior. EBBC by 5-year birth cohort assumed a minimum age at infection and age-dependent progression rates; three versions, with varying age effects, were investigated using AIDS cases diagnosed prior to the introduction of highly active antiretroviral therapies (HAART). RESULTS: Compared with the no age-effect version, EBBC by birth cohort tended to produce flattened HIV incidence curves in country-exposure groups with < 1000 AIDS cases, reflecting effects of the neighbour prior when data become sparse. Otherwise, birth cohort analysis, with moderate effects of age on progression, gave initially increasing incidence curves and consistent patterns across countries, with the 1960-1964 cohort most affected. In the European Union, incidence is estimated to have peaked in 1983 among homosexual men and in 1988 among injecting drug users; 460000 persons were estimated to be living with HIV/AIDS at the end of 1995. CONCLUSIONS: Our improved methodology deals effectively with the change in AIDS case definition and has allowed quantitative assessments of the HIV epidemic by birth cohort using all AIDS cases diagnosed before 1996, thus providing a sound basis for public health policy at a time when estimation of more recent prevalence is compromised by the effects of HAART.

Reaching homosexual men for HIV surveillance through a gay magazine.

HIV surveillance in homosexual men is poor in most countries, as this risk group is difficult to sample. The aim of this study is to test the feasibility of reaching homosexual men for national HIV surveillance using gay community media. In 1989, a questionnaire on general gay issues, with a section on AIDS, was included in a widely sold gay magazine in the Netherlands. Among 17,700 sold copies, 1134 responses were obtained from males (6%). Of these, 669 men (59%) gave their address, of which in turn 84% responded to a questionnaire on risk behaviour in 1990. In 1991/1992, the 669 men were asked to participate in an HIV serosurvey, in which eventually 308 participated with a blood test (46%) and 147 without (total 68%). Participation in the serosurvey with blood test was associated with reporting multiple partners in 1989. Twenty participants were infected (6.5%). In logistic regression analysis, risk factors for infection were recent unprotected receptive anal intercourse with multiple partners (odds ratio (OR): 10.7; 95% confidence interval (CI): (2.18-52.2); one partner 1.17 (0.31-4.48); none 1) and living in Amsterdam (OR: 3.92; 95% CI: (0.99-15.5); urbanised western Netherlands 2.15 (0.57-8.03); elsewhere 1), while a high educational level was protective (OR: 0.29 (0.08-0.96); middle 0.41 (0.11-1.54); low 1). Among those who participated in 1991/1992, risk behaviour increased between 1989 and 1991/1992 (reporting multiple casual partners rose from 55% to 64%; reporting inconsistent condom use with receptive anal sex from 58% to 71%). Using a predictive model which included self-reported serostatus in 1989, the HIV prevalence rate in 1991/1992 among all male responders to the 1989 questionnaire was estimated to be 5.3% (95% CI: 3.1 7.7%). In conclusion, unless initial response is improved, recruitment through a gay magazine may not allow reliable estimates of HIV prevalence in homosexual men. However, it can be useful at the national level for monitoring changes in prevalence and risk behaviour over time, geographical differences and risk factors for infection.

Universal HIV screening of pregnant women in England: cost effectiveness analysis.

OBJECTIVE: To estimate the cost effectiveness of universal, voluntary HIV screening of pregnant women in England. DESIGN: Cost effectiveness analysis. Cost estimates of caring for HIV positive children were based on the stage of HIV infection and calculated using data obtained from a London hospital between 1986 and 1996. These were combined with estimates of the health benefits and costs of antenatal screening so that the cost effectiveness of universal, voluntary antenatal screening for HIV infection in England could be estimated. MAIN OUTCOME MEASURES: Lifetime, direct costs of medical care of childhood HIV infection; life years gained as a result of the screening programme; net cost per life year gained for different pretest counselling costs; and different prevalence rates of pregnant women who were unaware that they were HIV positive. RESULTS: Estimated direct lifetime medical and social care costs of childhood HIV infection were pound178 300 using a 5% discount rate for time preference (1995-6 prices). In high prevalence areas screening pregnant women for HIV is estimated to be a cost effective intervention with a net cost of less than pound4000 for each life year gained. For areas with comparatively low prevalence rates, cost effectiveness could be less than pound20 000 per life year gained, depending on the number of pregnant women who are unaware that they are infected and local screening costs. CONCLUSIONS: Our results confirm recent recommendations that universal, voluntary antenatal HIV screening should be implemented in the London area. Serious consideration of the policy should be given for other areas in England depending on local prevalence and screening costs.

An age-period-cohort analysis of 50,875 AIDS cases among injecting drug users in Europe.

BACKGROUND: The long average incubation time from HIV infection to AIDS makes it difficult to estimate recent HIV transmission from AIDS incidence data. Age-period-cohort (APC) analysis can separate out the effects of age, calendar time and birth cohort to provide a clearer picture of transmission trends. METHODS: AIDS incidence data from 1981 to 1994 among intravenous drug users (IDU) for 12 Western European countries were used. Yearly incidences per 100,000 population or 100,000 person-years were calculated by age at diagnosis and 5-year birth cohort (1950-1954, 1955-1959, 1960-1964, 1965-1969 and 1970-1974), and corrected for reporting delay. Incidence patterns were compared between birth cohorts and countries. RESULTS: For most countries the impact was greatest on the cohort born 1960-1964. Comparing incidence patterns in the 1965-1969 to 1960-1964 cohorts suggest the epidemic has plateaued at low to intermediate levels in Austria, Greece and the North-Western European countries, and at high levels in France, Italy and Switzerland. For most countries transmission amongst the 1970-1974 as compared to the 1965-1969 cohorts could not be assessed due to small numbers and short follow-up time. In Spain the epidemic was uncontrolled with a high incidence among recent birth cohorts. In Portugal the epidemic was still at an early and expanding phase. CONCLUSIONS: The APC analysis revealed large country differences in the dynamics of the HIV/AIDS epidemic among IDU. Full interpretation of these differences is dependent on information from other sources about the local public health response and trends in drug injecting behaviours. Earlier introduction of the virus and higher prevalence of injecting drug use may explain some of the generally higher incidence in Southern European countries, but the larger part of it is most likely explained by local characteristics of drug users, such as younger age and more frequent sharing of needles and syringes, and a less effective public health response.

Broader vaccination of expatriates against HBV infection: do we reach those at highest risk?

BACKGROUND: The effects of the implementation of a new Dutch hepatitis B virus (HBV) vaccination strategy (1991) for expatriates on HBV vaccination status and HBV infection prevalence were evaluated in a group of 864 expatriates returning from HBV-endemic areas. METHODS: During a routine medical examination at the participating medical centres Dutch expatriates were asked to complete a questionnaire and to donate a serum sample for HBV testing. Blood was tested for antibodies against the hepatitis B core (anti-HBc) and surface antigens (anti-HBs). The serological data were related to information gathered on aspects of residence, sexual risk behaviour and occupational risks. RESULTS: A significantly higher percentage of expatriates (37%) were vaccinated compared to a previous study in 1987-1989 (14%). However, the percentage of expatriates with HBV infection markers (5%) had not decreased significantly. Moreover, the risk for HBV infection, as determined with a questionnaire, was still affected by well-known risk factors such as homosexual contacts (odds ratio [OR] = 6.6, 95% CI: 1.7-26), more than five casual local partners (OR = 3.6, 95% CI: 1.2-11) and more than five occupational accidents in the last 3 years (OR = 20, 95% CI: 2-187). Detailed analysis of the vaccination status indicated that especially young female expatriates with low risk behaviour (65%) were protected, while older male expatriates with high risk behaviour were less protected (20%). CONCLUSION: We conclude that the new vaccination strategy has resulted in a higher percentage of expatriates protected. However, only a small proportion was reached of those at highest risk for HBV infection.

Methods for estimating HIV prevalence: A comparison of extrapolation from surveys on infection rate and risk behaviour with back-calculation for the Netherlands.

OBJECTIVES: To compare HIV prevalence estimates (total number infected) by using extrapolation from surveys on infection rate and risk behaviour (EIR) in specific segments of the population and back-calculation (BC) on reported AIDS cases. To discuss potential sources of bias and error, and to identify areas for improvement of the methodology. DESIGN: Systematic comparison and epidemiological assessment of data input, underlying assumptions, and output. METHODS: Low, possibly unbiased and high estimates of HIV prevalence as of January 1996 for homo/bisexual men, injecting drug users. heterosexual men and women with multiple partners, and blood transfusion recipients and haemophiliacs were derived from surveys and continuous data collections on HIV infection rate and risk behaviour in the Netherlands between 1992 and 1996. These were compared with estimates (point and 95 % CI) by empirical Bayesian BC on AIDS cases 1982-1995. RESULTS AND CONCLUSIONS: The estimate of HIV prevalence by EIR was 13,806 with low and high estimates of 9619 and 17,700, respectively. The HIV prevalence estimate by BC was 8812 (95% CI: 7759-9867). The available data from EIR are too limited for accurate estimates of HIV prevalence. EIR estimates could be improved considerably with more precise data on prevalence of risk behaviours and HIV prevalence rate for homosexual men. More confidence can be put in the BC estimates, but these could be underestimates because of the age effect on incubation time, pre-AIDS treatment and relapse of risk behaviour. BC estimates could be improved by a better representation of the incubation time distribution (including the effect of age there-upon), better data on the effectiveness and uptake of pre-AIDS antiretroviral treatment and prophylaxis of opportunistic infections, and on the level of underreporting.

Occupational risk of HIV infection among western health care professionals posted in AIDS endemic areas.

In this study on occupational risks of HIV infection among 99 Dutch medics working in AIDS endemic areas, 61% reported percutaneous exposures during an average stay of 21 months. The mean number of injuries was lower among physicians (2.0 versus 3.9 per year) and higher among nurses (1.9 versus 1.2) than in previous research conducted in 1987-1990 among Dutch medics returning from Africa. But the reduction of exposures among physicians might be explained by the fact that the number of procedures they carried out was less in the later study. Also among nurses a shift of tasks was seen. On the basis of an estimated HIV prevalence in the patient population of 19%, a chance of transmission per accident of 0.3%, and 1.9 percutaneous exposures per year, the mean occupational risk of HIV infection per year can be estimated at 0.11% per person. Besides length of stay and number of activities, characteristics of the work setting were associated with the frequency of different kinds of injuries. From the analysis of 109 extensive descriptions of recent accidents, it appeared that the majority of the injuries occurred during routine activities and were self-inflicted. Injuries with hollow needles usually occurred after the actual medical act (e.g. during recapping). Carelessness (e.g. due to fatigue) or being in a hurry (e.g. because of an emergency) were also often the cause of percutaneous injuries, as were the poor quality of the equipment, lack of professional skills, or a combination of these factors. Prevention activities are still important to reduce the frequency of occupational exposures. But they will not eliminate them totally; from the descriptions of recent exposures it was clear that some of the injuries occurred in spite of precautions.

PIP: By the end of 1995, a total of 79 occupationally acquired HIV cases had been documented worldwide among health care workers. As part of a larger study on the sexual and occupational risks of HIV among Dutch expatriates, 99 medical professionals (48 physicians and 51 nurses, midwives, or anesthesia assistants) who had worked in AIDS-endemic areas were identified. 96% of physicians and 92% of nurses had last worked in sub-Saharan Africa--typically in rural areas or refugee camps. When tested upon return to the Netherlands, none of these health care professionals was HIV-infected. However, 71% of physicians and 51% of nurses experienced at least one percutaneous exposure (mean number, 2.0 and 1.9, respectively) during an average stay abroad of 2.3 and 1.2 years, respectively. 235 of the 337 accidents described involved solid needles. Given an estimated HIV prevalence in the patient population of 19%, an HIV transmission per accident of 0.3%, and 1.9 percutaneous exposures per year, the occupational HIV risk per health worker per year in countries with high HIV prevalence can be estimated as 0.11%. Most injuries occurred during routine acts and tended to be self-inflicted as a result of negligent needle disposal, recapping errors, cleaning materials for reuse, carelessness due to fatigue, or rushing. Accidents with solid needles were significantly more likely to occur if more procedures were performed, the stay abroad was longer, co-workers were local, and management consisted of local personnel. Worry about occupational exposure to HIV was reported to occur sometimes in 68% of physicians and nurses, regularly in 12%, and often in 6%. HIV prevention programs for health workers should address not only how to prevent occupational exposure, but also how to prepare for the emotional responses to exposure and the consequences this may have for sexual behavior.

HIV-associated dementia: clinical, epidemiological and resource utilization issues.

Among mental disorders associated with HIV infection, dementia is the one most likely to have a major impact on public health, both as a result of the high levels of individual disability, and the greater demand of health care resource utilization. Epidemiologic and economic impact of HIV-associated dementia needs to be estimated, in order to provide policy makers and health managers with the information required for decision making and resource allocation. An increase in HIV encephalopathy prevalence rates may be expected as a consequence of longer survival time in dementia patients and in patients with other AIDS defining disease (longer survival increases the risk of developing HIV encephalopathy). A resource utilization study shows that, in the chronic stage of the disease, in-patient days per person-year are almost double in AIDS subjects with neurological complications as compared with those without neurological complications; no major difference appears when considering out-patients consultations and day-care treatments. In conclusion, a significant rise in resource utilization and in related costs may be anticipated as a consequence of the increasing prevalence of HIV encephalopathy. Further studies seem necessary to compare different approaches in the management of this debilitating disease, in view of a more rational utilization and allocation of resources.

A birth cohort analysis of AIDS in Europe: high incidence among young persons at risk.

OBJECTIVES: To study trends in AIDS incidence in Europe by age and year of birth. DESIGN: Age-period-cohort analyses were adopted to distinguish the different time factors of calendar year, age and year of birth. METHODS: Non-aggregate AIDS incidence data from 12 European countries (1978-1994) were adjusted for reporting delay and expressed per unit of population (per 100000 persons or 100000 person-years). Age-specific incidence patterns (absolute level and rate of increase) were compared between 5-year birth cohorts for homo-/bisexual men, injecting drug users (IDU) and heterosexual contact cases. RESULTS: Mean age at diagnosis increased strongly amongst IDU, but less so among homo-/bisexual men and heterosexual contact cases. Of a total 110646 reported cases (116311 after adjustment for reporting delay), 87167 (78.8%) were among people born in 1950-1974 [91951 (79.1%) after adjustment for reporting delay]. The relative impact on specific birth cohorts differed strongly by exposure group. Incidences at age ranges of 20-24 and 25-29 years among cohorts born in 1965 and after were about the same level (homo-/bisexual men, IDU) or higher (heterosexual contact cases) than older birth cohorts when these were in the same age range; rates of increase were less among homo-/bisexual men and IDU, but higher among heterosexuals. There were large differences between counties. CONCLUSIONS: Overall, AIDS incidence among cohorts born in 1965 and after is about the same level (homo-/bisexual men, IDU) or higher (heterosexual contact cases) than older cohorts when these were in the same age range. Rates of increase of AIDS incidence curves suggest reduced HIV transmission amongst the most recent cohorts of homo-/bisexual men and IDU, but among young heterosexuals the epidemic is still expanding.

Underlying reasons for sexual conduct and condom use among expatriates posted in AIDS endemic areas.

Among people who work abroad, sexual activity and therefore the risk of HIV infection appear to be relatively high. Little is known about the factors that influence sexual conduct when staying abroad, separated from their usual social environment. This is why 55 expatriates who had been sexually active in AIDS endemic areas were selected for an in-depth interview from the original sample of 864 Dutch expatriates participating in a study on sexual behaviour and HIV infection. The social and cultural context in which the sexual contacts took place was addressed in these interviews. Qualitative analysis of the data led to the identification of four styles with regard to the meaning of and motivations for having sex abroad: 'the unprepared', 'the fanatical', 'the unaffected' and 'the slightly accessible'. These styles are described separately and attention is paid to the association of these styles with protection behavior.

PIP: In developing countries, unlike in the Western world, HIV is transmitted mainly through heterosexual intercourse. Therefore for Western travellers, unprotected heterosexual contact is more risky in developing countries than in their countries of origin, in which the HIV epidemic has remained largely confined to homosexual men and IV drug users. Sexual activity and the risk of HIV infection are relatively high among people who work abroad. 55 Dutch expatriates who had been sexually active in AIDS-endemic areas were interviewed about their sexual history, the social and cultural contexts in which their sexual contacts occurred, and the number and types of their sex partners. With respect to the risk of HIV infection, questions were posed about participants' experience with condoms before departure, whether they took condoms with them, their assessment of the risk of unsafe sex abroad, their intentions to use condoms, and condom use with various types of partners. Four different approaches to and experiences with sex abroad were identified: the unprepared among whom sex happened unexpectedly, those who had to have sex while abroad, those who see no difference between sex abroad and sex in the home country, and those who find sex abroad to be different from that at home, but were nonetheless prepared to have sex while abroad.

Sexual risk of HIV infection among expatriates posted in AIDS endemic areas.

OBJECTIVE: To assess the prevalence of HIV infection and related risk factors among Dutch expatriates returning from assignment in sub-Saharan Africa, Latin America, and South and South-east Asia. METHODS: From July 1994 to January 1996, a questionnaire on the risks of sexual exposure was completed by 864 respondents, and blood samples were taken. RESULTS: Of the 634 men, 41% reported having sex with casual or steady local partners and 11% with casual or steady expatriate partners, during an average stay of 26 months in the previous 3 years. Of the 230 women, these figures were 31 and 24%, respectively. Of the men with local casual partners (29%), 59% paid for sex at least once. For men as well as women, having sexual contacts abroad was associated with younger age, positive intention prior to departure to have sex abroad, being single at departure, and, only for the men, working for a commercial organization, and feelings of loneliness and boredom. Among men, consistent condom use with casual local partners was 69%, and with casual expatriate partners 63%. Among women, these figures were 64 and 48%, respectively. Consistent condom use with steady local or expatriate partners was much lower. Among men, non-consistent condom use with casual partners was more prevalent if they had been abroad for a longer time, condoms were not taken along from The Netherlands, the country where they were posted was Asian, and the estimated HIV prevalence among the local population was lower. Among the women, non-consistent condom use was more prevalent if condoms were not taken along, and if they did not have the intention before departure to have sex abroad. Of the persons from whom blood could be obtained, one man was HIV-positive. Another man who refused to participate in the study indicated that he was HIV-positive. CONCLUSIONS: Although 23% of the expatriates had unprotected sex with partners from endemic areas, very few HIV infections were found. In comparison with a previous study among this population carried out in 1987-1989, which found five out of 1968 expatriates to be HIV-infected, consistent condom use with casual local partners did increase considerably (from 21 to 67%). However, health education is needed to reduce the risk of HIV infection, which should emphasize the sociocultural differences in sexual practices.

PIP: A survey conducted among 864 Dutch expatriates returning home from assignment in AIDS-endemic areas in sub-Saharan Africa, Latin America, and South and South East Asia revealed a low rate of HIV infection, despite widespread high-risk sexual practices. During an average stay out of the country of 26 months in 1991-96, 41% of the 634 male respondents reported sex with casual or steady local partners and 11% with casual or steady expatriate partners. Among the 230 female expatriates, these rates were 31% and 24%, respectively. 58% of men with casual local partners paid for sex at least once. Among men, consistent condom use was practiced in 69% of encounters with casual local partners and 63% of the time with casual expatriate partners. Among women, these rates were 64% and 48%, respectively. The prevalence of consistent condom use with casual local partners in this study was three times greater than that identified in a study conducted among Dutch expatriates in 1987-89. Condom use with regular local or expatriate partners was substantially lower (16.1-27.8%), however. Inconsistent condom use with casual partners was significantly associated, among men, with being abroad for a longer period of time, failure to bring condoms with them from the Netherlands, posting in an Asian country, and a relatively low estimated HIV prevalence in the local population. Among women, these risk factors were failure to take condoms to their destination and lack of intention at departure to have sex abroad. Only one case of HIV infection was detected in the 847 respondents who underwent serologic testing. Since expatriates function as a bridge between areas with high and low HIV prevalence, educational campaigns that prepare departing workers for differences between the sexual culture at home and abroad and encourage them to take a supply of condoms are recommended.

[AIDS epidemic in The Netherlands: current developments in transmission route, age and nationality]. / AIDS-epidemie in Nederland: recente ontwikkelingen naar transmissieroute, leeftijd en nationaliteit.

OBJECTIVE: To document the recent developments in the course of the AIDS epidemic in the Netherlands, 1982-1995. DESIGN: Descriptive. SETTING: National Institute of Public Health and Environment, Bilthoven, Municipal Health Service, Amsterdam, and Inspectorate of Public Health, Rijswijk, the Netherlands. METHOD: Based on the new AIDS patients reported to the Inspectorate of Public Health, the incidence figures were calculated by risk group (homo/bisexual men, intravenous drug users and heterosexual men and women), by birth cohort defined by 5 successive years of birth, and by nationality, in order to characterise sub-epidemics. RESULTS: Among homo/bisexual men AIDS incidence has been stabilizing in recent years. Among intravenous drug users and heterosexuals incidence continues to rise but at a low level compared with homo/bisexual men. Among homo/bisexual men and intravenous drug users mean age at AIDS diagnosis is rising in conjunction with reduced incidence among young persons born in 1965-1969 when compared with the incidence among persons born in 1960-1964 when at the same age. By contrast, among heterosexuals a decline in mean age at diagnosis is observed and this decline coincides with undiminished rise of incidence among persons born in 1965-1969. Among heterosexual patients an increasing and disproportionate number have the nationality of a sub-Saharan African country. CONCLUSION: Future AIDS incidence among homo/bisexual men and intravenous drug users will probably be lower than it currently is. Regarding heterosexuals the undiminished growth of the number of young AIDS patients and the increasing proportion of patients from abroad make such an assessment more difficult.

[HIV/AIDS in The Netherlands: improved treatment possibilities necessitate HIV instead of AIDS surveillance]. / HIV/AIDS in Nederland: betere behandelingsmogelijkheden maken HIV- in plaats van aidssurveillance noodzakelijk.

An abrupt decrease of the number of reported new AIDS cases took place in the first half of 1997 in the Netherlands. This decrease was most prominent in homosexual/bisexual men and intravenous drug users, and less conspicuous in heterosexual men and women. The number of heterosexual patients with a non-Dutch nationality even increased compared with the first half of 1996. The most probable explanation of these observations is the introduction of improved treatment possibilities for HIV-infected people starting July 1996, which lead to a longer incubation period. Owing to these developments monitoring the HIV/AIDS epidemic in the Netherlands will depend more and more on HIV status surveillance instead of on registration of new AIDS cases.

Laboratory-based HIV surveillance with information on exposure: importance of discriminating person-based from test-based results.

Within a surveillance programme in a Regional Public Health Laboratory anonymous information on HIV test, requesting physician and tested individual is automatically selected, regardless of test result. Thereby, personal identifiers are transformed into unique but meaningless numeric codes. Besides, requesting physicians receive a questionnaire on indication for testing (response 87%). Between April 1989 and June 1993 12,219 HIV tests were performed in 10,972 individuals. The percentage of positive tests (2.1%) was twice the percentage of positive individuals (1%). No increase in number of new infections was observed over time. Of individuals, 41.6% were tested due to third party requests (mainly insurance): HIV was demonstrated once (0.03%). Among the remainder, with medical indications, seroprevalence was 1.4%. At relatively little expense, we were able to provide valid information about patterns of HIV-testing and HIV seroprevalences among people tested in routine medical practice. Prevention of double counts proved to be important. Extension to other Dutch areas is expected.