In the Netherlands, the proportion of heterosexual people among the HIV infected population is rising. A substantial proportion of these individuals have a non-Dutch background, with 21% being originally from Surinam, the Netherlands Antilles, and Aruba.¹ A previous study among Surinamese, Antillean, and sub-Saharan migrants living in the Netherlands reported high rate of partner change, concurrent partnerships, and history of sexually transmitted infections (STI).² In a study among sub-Saharan Africans living in London, 40% of the men and 20% of the women had acquired a new sexual partner while travelling abroad.³ Unprotected sex in the homeland could be an important risk factor for HIV infection, because the estimated prevalence rates for Surinam, the Antilles, and Aruba are 90, 50, and 21 HIV cases per 100 000 population, respectively, versus 10 cases per 100 000 population in the Netherlands.^1,4,5 Moreover, molecular epidemiological research suggests an increased risk for importing HIV infection. Half of the HIV positive people originating from Surinam and the Antilles are believed to have been infected during a homeland visit.⁶

Since more insight into sexual risk behaviour on homeland visits is needed to develop prevention measures, we studied the characteristics of Surinamese and Antillean men and women who visit their homeland and the determinants of having unprotected sex during those visits.

METHODS

Study population

In a study in the south eastern area of Amsterdam 1660 people originating from Surinam, the Antilles, and sub-Saharan Africa were recruited from May 1997 to July 1998 in market places, shopping areas, community houses, and churches.² Inclusion criteria for the present study were age between 15 years and 55 years and self identification as Surinamese or Antillean (n = 1025). After oral informed consent, saliva was taken and tested for antibodies against HIV. Interviews took place using a structured questionnaire concerning demographics, mobility, and sexual behaviour. Participants were asked about the number of homeland visits in the past 5 years, the local sexual contacts during those visits, and condom use with those contacts.

The study was approved by an ethics committee.

Definition of variables and statistical analyses

In this study we determined variables associated with (1) visiting the homeland and (2) having unprotected sex on visits. Unprotected sex in the homeland was defined as: a lack of consistent condom use (that is, not always) when having sex with local partner(s) during visits in the past 5 years.

When the prevalence of an outcome is high, odds ratios can be misleading if interpreted as relative risks.⁷ Because the prevalence of homeland visits was high in this study, prevalence rate ratios instead of odds ratios were used to describe the association between such travel and its determinants. The analyses were done with GENMOD procedure, using a generalised linear model for binomial outcomes with a logarithmic link function. Logistic regression was used to study determinants of unprotected sex on homeland visits. Variables with a p<0.10 in univariate analysis were entered into the multivariate model.

RESULTS

General characteristics

The total study population consisted of 494 men and 531 women. The majority of men (79%) and women (77%) were Surinamese (table 1). The median age of men was 28 years and their median length of stay in the Netherlands was 10 years (interquartile range (IQR) 19–37 years). For women, the median age was 31 years (IQR 3–21 years), and their median length of stay was 11 years (IQR 5–22 years). Compared with Surinamese, both Antillean men and women reported more often a previous HIV test and less frequently a diagnosed STI. More than 50% of the men and women from both countries had a low educational level (that is, lower vocational education), and 82% of the men and 69% of the women were single. HIV prevalence was 0.8% (95% CI 0.3 to 1.5).

Travelling to country of origin

Over 5 years, 38% of the 494 men and 42% of the 531 women visited their homeland. In multivariate analysis, married and divorced men (prevalence rate ratio (PRR) 1.37, 95% CI 1.07 to 1.57) and men living in the Netherlands ⩾7 years (PRR 1.42; 95% CI 1.12 to 1.65) were more likely to visit their homeland than single men and men living in the Netherlands for <7 years. Compared to unemployed men, employed men travelled more frequently (PRR 1.48; 95% CI 1.14 to 2.05). Homeland visits were more often observed among men with high educational level (that is, higher vocational education/university) compared to those with low educational level (PRR 1.53, 95% CI 1.16 to 1.62).

Women with age ⩾36 years (PRR 1.48, 95% CI 1.05 to 2.16) were more likely to visit their homeland than women younger than 36 years. Those who were living in the Netherlands for ⩾8 years (PRR 1.34, 95% CI 1.06 to 1.71) travelled more often than women who were living in the Netherlands for <8 years.

Unprotected sex with partner in country of origin

Of the 186 men who travelled to their homeland, 47% acquired a local sexual partner, as did 11% of the 222 women. Unprotected sex with local partners occurred in 31/87 (36%) of these men and in 12/24 (50%) of the women.

Having >1 partner in the past 5 years was, among female travellers, the only variable significantly (OR: 13.57) associated with unprotected sex with local partners. Other variables did not confound this association. In multivariate analysis, Surinamese men had a 10.7-fold higher odds of having unprotected sex in their homeland than did Antillean men. Men with a history of ⩾1 STI had a 12.5-fold higher odds of having unprotected sex than men without a history of STI (table 2).

DISCUSSION

The relation of the Netherlands with former colonies enables mobility of migrants. Of our respondents, 40% visited their homeland in a 5 year period. In line with our results, a study among sub-Saharan Africans in London has shown that homeland travel is associated with UK residence for more than 10 years, a high education level, and full time employment.³

Men were more likely than women to establish new sexual relationships in their homeland. However, among all those with such a relationship, the percentage of unprotected sex was higher for women. Clearly, both men and women are vulnerable to HIV infection and other STIs while travelling.

Research regarding sexual risk behaviour while travelling to the country of origin is limited.³

In line with our and the London study, studies among expatriates and holiday makers report percentages of sex with new partners of 5% and 60%.^8,9,10,11 They also identified a significant association between multiple sexual partners in country of residence and unprotected sex during visits. We also found that ethnicity and a history of ⩾1 STI were associated with unprotected sex while travelling. This is inconsistent with findings from studies among expatriates and holiday makers.^8,9,11 Just like expatriates and holiday makers, migrants have a “bridge function” between areas with high and low HIV prevalence. Their sexual risk behaviour in the homeland and in the Netherlands acts as a bridge between two heterosexual populations.^8,9,11,12

Therefore, such behaviour of migrants in both their past and present countries should be studied in more detail. Findings will help to differentiate migrant cultures and to identify travellers at high risk for STIs and HIV infection. Education and effective pretravel counselling on sexual behaviour should target migrant travellers who are likely to engage in sexual risk behaviour.