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.

AIDS-related knowledge, attitudes, and behavior: a comparison of Dutch students and dropouts

School dropouts are considered an important target group for AIDS prevention. They are expected to be less knowledgeable about AIDS and to show a higher degree of risky behavior as compared with their school-attending peers. Several small-scale studies among specific groups of dropouts seem to confirm such expectations. However, due to differences in methodology, it is often difficult to compare the results of such studies with findings for youths who have not dropped out of school. The present study sought to remedy this by examining AIDS-related knowledge, attitudes, and behavior among comparable samples of Dutch secondary school students and dropouts (excluding homeless and drug-addicted adolescents). The two groups were compared with regard to knowledge about AIDS prevention, attitude toward condom use, intention to use condoms, sexual history, and condom use. Contrary to expectations, few differences were found. It was concluded that, in most respects, dropouts are similar to those who have remained in school.

Prevalence of psychiatric disorder in the general population: results of The Netherlands Mental Health Survey and Incidence Study (NEMESIS)

This article reports the initial results of a prospective study on the prevalence of psychiatric disorders in the Dutch population aged 18-64. The objectives and the design of the study are described elsewhere in this issue. A total of 7076 people were interviewed in person in 1996. The presence of the following disorders was determined by means of the CIDI: mood disorders, anxiety disorders, eating disorders, schizophrenia and other non-affective psychoses, and substance use disorders. Psychiatric disorders were found to be quite common. Some 41.2% of the adult population under 65 had experienced at least one DSM-III-R disorder in their lifetime, among them 23.3% within the preceding year. No gender differences were found in overall morbidity. Depression, anxiety, and alcohol abuse and dependence were most prevalent, and there was a high degree of comorbidity between them. The prevalence rate encountered for schizophrenia was lower (0.4% lifetime) than generally presumed. A comparison with findings from other countries is made. Relevant determinants of psychiatric morbidity were analysed.

The Netherlands Mental Health Survey and Incidence Study (NEMESIS): objectives and design

The article describes the objectives and design of a prospective study of the prevalence, incidence and course of psychiatric disorders in a representative sample of non-institutionalized Dutch adults. A total of 7146 men and women aged 18-64, contacted through a multistage sample of municipalities and households, were interviewed at home in 1996. The primary diagnostic instrument was the CIDI, which determines the lifetime occurrence of DSM-III-R disorders. The disorders included were: mood disorders, anxiety disorders, eating disorders, schizophrenia and other non-affective psychotic disorders, and dependence and abuse of psychoactive substances. Follow-up measurements in the same sample were scheduled at 12 and 36 months. The net response to the first measurement was 69.7%. Poststratification weightings were applied for gender, age, marital status and degree of urbanization. Limitations and advantages of the study design are discussed. Findings are reported elsewhere in this issue.

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.

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.

[Psychiatric morbidity among adults in The Netherlands: the NEMESIS-Study. II. Prevalence of psychiatric disorders. Netherlands Mental Health Survey and Incidence Study]

OBJECTIVE

To determine the prevalence of psychiatric disorders in non-institutionalised Dutch adults.

DESIGN

Cross-sectional.

SETTING

Trimbos Institute, Utrecht, the Netherlands.

METHODS

A representative sample of 7076 adults (18-64 years) in the Netherlands' population were interviewed in 1996 to determine the prevalence of mental disorders ever, in the previous 12 months and in the previous month. Objectives and study design are described in the previous article (1997: 2448-52). The 'Composite international diagnostic interview' (CIDI) was used to assess the following mental disorders according to Diagnostic and statistical manual of mental disorders, 3rd revised edition (DSM-III-R): affective disorders, anxiety disorders, eating disorders, schizophrenia and other non-affective psychoses, substance dependence and substance abuse.

RESULTS

Mental disorders were common in the general population: the prevalence 'ever' of all disorders was 41.2%, the 12-month prevalence 23.5%, without sex differences. Depression, anxiety disorders and alcohol abuse and dependence showed high prevalence and comorbidity. The prevalence 'ever' of schizophrenia and other non-affective psychoses was low (0.4%).

[Psychiatric morbidity among adults in The Netherlands: the NEMESIS-Study. I. Objectives, design and methods. Netherlands Mental Health Survey and Incidence Study]

OBJECTIVE

To determine prevalence, incidence and course of psychiatric disorders in non-institutionalised Dutch adults.

DESIGN

Prospective and cross-sectional.

SETTING

Trimbos Institute, Utrecht, the Netherlands.

METHOD

A multistage, stratified random sampling procedure was used to obtain a sample of 7076 adults (18-64 years). Respondents were interviewed throughout 1996 in their homes. The main diagnostic instrument was the 'Composite international diagnostic interview' (CIDI), designed to assess lifetime prevalence of mental disorders according to Diagnostic and statistical manual of mental disorders, 3rd revised edition (DSM-III-R). The diagnostic categories were: affective disorders, anxiety disorders, eating disorders, schizophrenia and other non-affective psychoses, and substance use disorders (dependence and abuse). The sample was weighted towards national census data on sex, age, marital status and urbanicity.

RESULTS

The results of the first measurement (1996) will be described in the next article (1997:2353-60). The response rate was 64.2%. There were no indications that the psychiatric morbidity of non-respondents differed from respondents. The same respondents will be interviewed again after 12 (1997) and after 36 months (1999).

Condom use by Dutch men with commercial heterosexual contacts: determinants and considerations

We report responses from 559 clients of female prostitutes, with a view to determining to what extent previously identified factors play a part in condom use. To increase the response rate to advertisements in daily and weekly newspapers, interviews were held by phone. This procedure had the advantage of ensuring the anonymity many clients demanded. Of those clients having vaginal or anal contact (91%), 14% had not always used condoms in the previous year. Compared with consistent condom users, these men were less highly educated, had twice as many commercial contacts, and had more contacts with "steady" prostitutes. They were either more emotionally motivated to visit prostitutes than were consistent condom users or exhibited a stronger need for sexual variation. They showed a more compulsive attitude toward visiting prostitutes, had a more negative attitude toward prostitution in general, evaluated condoms more negatively, had a higher personal efficacy to achieve unsafe contacts, and had a higher general risk assessment, commensurate with their behavior. Men with only safe contacts had either an intrinsic or an extrinsic motivation for condom use. Among extrinsically motivated men, their behavior change was more recent and had not yet taken root: They still envisioned unsafe commercial sex to be possible in the future. Education aimed at the small group of men practicing unsafe contacts will not easily and directly lead to behavior change. But these educational activities may support prostitutes to persist in (consistent) condom use, regardless of clients' pressure to do otherwise.

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.

Segmentation of heterosexual prostitution into various forms: a barrier to the potential transmission of HIV

The results of an earlier Dutch study on prostitutes' clients, interviewed face-to-face, were cross-validated by means of telephone interviews, which both guaranteed anonymity and produced a larger sample of respondents (n = 559). Depending on their preference and financial resources, they had visited different types of prostitution; but about half of them had restricted themselves to one type. Inconsistent use of condoms was reported by 14% of the clients who had had vaginal or anal intercourse. Condoms were most frequently used in clubs, brothels and window prostitution, and least often in street, home and escort prostitution; in the last two sorts especially not with regular prostitutes. Whether or not prostitutes came from non-Western countries had no influence on protective behaviour of these clients. The formation of networks between different sorts of prostitution, through unsafe sexual contacts in two or more sorts, involved only 3% of respondents. Thus, prostitution in The Netherlands should be seen as a number of sparsely-connected networks rather than as a single network. The formation of networks between prostitution and the population at large is made possible by the 10% of the respondents who had had unsafe contacts with both commercial and private partners.

Professional HIV risk taking, levels of victimization, and well-being in female prostitutes in The Netherlands

Professional HIV risk taking (nonconsistent condom use with clients) of female prostitutes in The Netherlands is addressed within the context of (early) experiences with abuse, well-being, coping behavior, job satisfaction, and financial need. Data were gathered from 127 female prostitutes on condom use, financial need, and professional attitude, and on experiences with violence and abuse, physical complaints, psychosocial problems, and coping responses. Violent traumatic experiences were found to relate to more severe complaints and problems, and a higher frequency of emotion-focused coping strategies. A risk-taking protection style (as opposed to consistent condom use and selective risk taking) appeared to be associated with more severe experiences with violence, both in childhood and in adult life, with more frequent dissociation as a coping behavior, and with more psychosomatic complaints. Of all the relationships found, more severe experiences with violence on the job were most strongly related to a higher professional HIV risk.

Alcohol and drug use in heterosexual and homosexual prostitution, and its relation to protection behaviour

To assess the prevalence and effects of alcohol and drug use in heterosexual and homosexual commercial contacts, and the relationship between their use and unsafe sexual behaviour, 127 female prostitutes, 27 male prostitutes, 91 clients of female prostitutes and 24 clients of male prostitutes were interviewed face-to-face with the help of a semi-structured questionnaire. The respondents were living or working in different parts of The Netherlands. Alcohol and drug use was found to be relatively common among prostitutes. This was also so for the use of alcohol by clients, though to a lesser extent. Prostitutes' consumption varied widely according to the type of prostitution they were employed in. Those meeting their clients in clubs or bars reported the highest consumption of alcohol; hard drugs were used predominantly by street prostitutes. It appears that the main effects of alcohol and drug use are on how the individual experiences working as, or calling on, a prostitute, the social interaction between the two parties, and the sexual contact itself. The common assumption that drinking alcohol has negative effects on condom use was not borne out; though female prostitutes working under the influence of drugs were significantly more likely to report unsafe sex. The degree to which commercial partners were judged to be under the influence of alcohol or drugs was not found to bear upon the frequency of respondents' condom use. For those prostitutes who use hard drugs, this use plays an important role in their engaging in unsafe sexual activities. Prevention activities should focus especially on this group, and should take into account the role of such drug use.

Social transmission routes of HIV. A combined sexual network and life course perspective

A combined sexual network and lifecourse perspective is proposed as a basis for reconstructing the sexological infrastructure of HIV dissemination. Necessary data are drawn from a representative sample survey of 1001 adults (age range 18-50 years) in the Netherlands. Heterosexual respondents' behavioural risk level, expressed in the number of unprotected sexual interconnections with primary and secondary partners, is found to be related to both age and relational status, though these variables cannot fully predict risk. While those under 24 years of age are over-represented in the larger components of sexual networks, above 32 years of age there is a small group who follow a lifestyle of regularly changing sexual partners.

Contextual and interactional factors influencing condom use in heterosexual prostitution contacts

The protection behavior of prostitutes and prostitutes' clients has been studied from a contextual and an interactional point of view. Different protection styles (subject's cognitive and behavioral position regarding condom use) have been identified in both prostitutes (N = 119) and clients (N = 91). Risk-taking prostitutes were found to have the least favorable working conditions, to have the highest financial need, to have the lowest levels of well-being and job satisfaction and to have been victimized more often than consistent condom users and selective risk-taking prostitutes. Consistent condom users among the clients were found to be better educated, to have a less strong external Health Locus of Control, to evaluate condoms and visiting prostitutes more positively, and prostitutes less negatively, and to have more fear of AIDS than non-consistent condom using clients. Various protection styles were found to be thoroughly intertwined with different interaction scenarios. Four different interaction scenarios (a standard, a romantic, a friendship and a fighting scenario) with a different chance of condom use are set forth. It is shown that the scenario approach gives good insight into the process by which unsafe sex in commercial contacts comes about. For both actors, the context and the meaning of prostitution influence the way they play the game. The interaction and its outcome in their turn reinforce their attitudes towards prostitution. Implications for AIDS prevention are discussed.

Male prostitutes and safe sex: different settings, different risks

Twenty-seven male prostitutes were interviewed extensively about their work and considerations relating to safe sex with clients. Important differences were found between street prostitutes and those working at home. Street-workers were more likely to be using hard drugs, to have a heterosexual preference, to have no other occupation, to have more clients, but less steady ones, and to have a more negative working attitude. Sexual techniques most often practised were manual and oral contact; however, most prostitutes also practised either insertive or receptive anal intercourse. Homosexual male prostitutes reported more receptive anal intercourse than did their heterosexual male colleagues; but no such differences were found in insertive anal intercourse. Prostitutes were most likely to have had anal intercourse with steady clients, with clients whom they trusted regarding condom use, or with clients they felt sexually attracted to; and also when in dire need of drugs. Of those who had practised anal intercourse in the previous year, a minority had not consistently used condoms. The same factors that encourage anal intercourse also appear conducive to unprotected intercourse.

The effectiveness of condom use in heterosexual prostitution in The Netherlands

OBJECTIVES

To assess the extent to which condoms are used effectively in commercial heterosexual intercourse. Data on the number of condoms that had broken or slipped off, the sexual technique during which this had occurred and the perceived cause of failure were collected. The use of non-water-soluble lubricants and non-fortified condoms during anal intercourse, and the demand for a greater variety of condom sizes were also examined.

SUBJECTS AND METHODS

One hundred and twenty-seven female prostitutes and 91 male clients from different parts of The Netherlands were interviewed face-to-face between July 1990 and March 1991.

RESULTS

Of those who used condoms during vaginal intercourse, 49% of the prostitutes had experienced condom breakage in the previous 6 months, and 16% of the clients in the previous 12 months. The breakage rate was 0.8% for prostitutes and 1.5% for clients. Condom quality was seldom reported as the cause; breakage was generally attributed to human factors, such as rough or prolonged intercourse, incorrect handling of the condom or the use of insufficient lubricant. Prostitutes also identified penis size as a cause. Condoms slipping off before or after ejaculation was reported less frequently than breakage. Thirteen per cent of clients and 36% of prostitutes expressed a need for either smaller or larger condoms. Of the prostitutes, 9% used oil or vaseline as a lubricant.

CONCLUSIONS

In view of the low rate of condom failure in heterosexual prostitution in The Netherlands, the potential spread of HIV by this means is small. The use of a greater variety of condom sizes may further reduce the failure rate. Few prostitutes remain ignorant about the adverse effects of oil-based lubricants on condoms.