Although the spread of HIV has been slower in Latin America than in Africa, the pandemic is now a well-established and growing problem there. Brazil has the highest number of AIDS cases in Latin America, and HIV prevalence among adults is 0.7%, which is close to the average for Latin America. Initially, AIDS in Brazil was concentrated among well-educated homosexuals living in the large cities in the south, but since 1990, rates have been increasing among heterosexuals, the less educated and northerners. By 1998, 61% of sexual transmission of HIV occurred via heterosexual contact; the male-to-female ratio of those who were infected was 2:1, compared with 16:1 in 1986; and 66% of men who had contracted the infection through heterosexual contact had had multiple partners, compared with 27% of women.¹

In contrast to the plethora of surveys on sexual behavior conducted in Africa, Europe and North America in response to the HIV pandemic, only a few surveys have been conducted in Latin America, particularly on men. One such survey is the 1996 Brazil Demographic and Health Survey (DHS), in which a nationally representative sample of men were interviewed on a range of topics, including extramarital sex.

Extramarital sex by men is likely to have different origins and consequences than risky sexual behavior by unmarried men, and thus merits separate analysis. The reasons for examining extramarital sexual behavior in the context of the spread of HIV and AIDS are obvious; however, as a four-site study² sponsored by UNAIDS confirms, the actual risk of infection depends on the overall prevalence of sexually transmitted infections (STIs) and HIV in particular communities and networks, and on the prevalence of cofactors, such as ulcerating infections. The epidemiological data from Brazil show that HIV and AIDS are increasing in prevalence among heterosexuals and within marital relationships, thus making extramarital sex an increasingly important topic for investigation.³ Understanding such risk behavior is essential for sound policy and program development, allows interventions to be better designed, targeted and evaluated, and may aid in predicting the future spread of the disease.

This article uses 1996 DHS data to analyze the correlates of extramarital sexual partnerships among Brazilian males, focusing on the potential behavioral impact of the increasing popularity of evangelical religions. The majority of evangelical groups in Brazil are Pentecostal, and although Pentecostals are a diverse group, they share a belief that life should be centered around religion. Adherents tend to be devout, reject "sinful" behavior and are encouraged to have strict moral codes that challenge the conduct of the larger society.⁴ Pentecostalism is a relatively new religion in Brazil and, unlike Catholicism, is more a religion of conversion than of birth. There are no recent official statistics on the number of Pentecostals in Brazil, but it is widely acknowledged that the growth is explosive.⁵ Globally, the number of Pentecostals in the world is increasing by almost 2% a year, and it is estimated that there will be over 800 million Pentecostals by 2025.⁶

METHODS

Data

In the 1996 Brazil DHS, 3,986 men aged 15-59 were selected for interview and 74% were successfully interviewed. Among those not interviewed, 76% were absent, 12% refused and 12% were not interviewed for other reasons.⁷ The subsample used in our analysis consists of men who were married or living with a partner at the time of the survey. We refer to these men as married—that is, we make no distinction between common law and registered marriages, and thus refer to any sexual intercourse with partners other than those with whom the men lived as extramarital sex. The weighted number of such men was 1,667 (unweighted 1,640).

The male questionnaire collected data on men's number of sexual partners in the last 12 months, the identity of their last three partners, condom use during their most recent sexual act with their last three partners, and their knowledge and perceptions of HIV and AIDS. As the spouse was one of the last three partners for all but three of the men surveyed, information on partner characteristics and condom use is available for a maximum of two extramarital partners. For the analysis, we selected three main outcomes: whether the respondent had an extramarital sexual partner in the last year, the number of such partners and condom use with each partner.

Human sexuality and sexual conduct have been analyzed from many different disciplinary perspectives: biology, economics, psychoanalysis, gender studies, social anthropology and so on. Because sexual expression is such as a fundamental aspect of the human experience, it is unlikely that any single analytical framework will gain wide acceptance. Certainly, there is no agreed on or well-founded theory of sexual networking in married men, nor was the 1996 Brazil DHS designed to test specific causal hypotheses. Nevertheless, the survey collected information on a wide range of factors that permit an unusually thorough examination of the correlates of behavior.

The predictor variables selected for the analysis include demographic factors (current age), prior sexual and marital history (age at first intercourse, number of marriages and nature of current marriage), ecological factors (urban-rural residence and region of residence), socioeconomic characteristics (education, occupation, value of household assets [as an indicator of wealth], household headship) and religious affiliation. The rationale for this selection is that research in other countries has revealed them to be potentially powerful influences on sexual behavior. For instance, age at first intercourse and nature of the main partnership have emerged as predictors of extramarital networking in industrialized and developing countries;⁸ socioeconomic status is often positively associated with the rate of acquisition of extramarital partners, though the health risks may be offset by greater condom use;⁹ and religion has been found to be a critically important factor in some societies.¹⁰

The questionnaire also collected data on men's knowledge of HIV and AIDS, and their perceived risk of or vulnerability to HIV infection. Causal interpretation of any statistical associations between these cognitive and attitudinal factors, however, is problematic. For instance, perceived risk of HIV infection may act as an influence on behavior, or it may be a consequence of recent behavior or may reflect both of these elements. Hence, these factors have been excluded from the main analyses.

Statistical Analysis

We used stepwise logistic regression to assess the correlates of having an extramarital partner in the last 12 months; Poisson regression was used to model the predictors of the number of such partners. We applied standardized sample weights (i.e., the inverse of the probabilities of selection corrected for nonresponse) and adjusted standard errors for both clustering and stratification using the survey command in Stata 7. For the analysis of condom use with the last two partners, a multilevel logit model was used to control for between-respondent variability, as well as to estimate any unobserved heterogeneity in the probability of condom use with these partners. We systematically examined correlates in the final models for significant first-order interactions, but found none.

RESULTS

Seventy-seven percent of men were Catholic and 11% were evangelical (Table 1, page 21); the remainder were members of other religions or were unaffiliated. More than three-quarters lived in urban areas, and half lived in the south. Sixteen percent of men reported household assets that were valued at less than US$300, 28% US$300-999, 19% US$1,000-1,999 and 37% at least US$2,000. Twenty-two percent were farmers or agricultural workers, 41% were professionals and 37% worked in service industries. Slightly more than half had had at most a primary school education. Twenty-three percent of men were younger than 30, 30% were 30-39 and 47% were 40 or older; the mean age was 39 (not shown). Twenty-eight percent had first had sex before age 15, 31% when they were 15-16 and 41% when they were 17 or older. The majority of men reported that they were married (81%) and that they were the head of the household (94%); of married and cohabiting men, 84% reported that their current marriage or cohabitation was their first.

Twelve percent of men reported having had an extramarital partner in the previous 12 months (Table 1); of these, half had had two or more such partners (not shown). The mean number of extramarital partners was 2.4 (Table 1). Of all extramarital partners, 77% were described as friends or lovers, 15 % as strangers and 4% as prostitutes, with the remainder being ex-wives and relatives (not shown). Of men's second-to-last and third-to-last partners, 57-63% were friends and 6-12% were lovers (Table 2). Sexual contact with prostitutes was uncommon (3-6%), but sex with strangers (presumably casual "pick-ups") was more frequently reported (13-18%).

Condoms are not a popular method of family planning within marriage in Brazil: In the 1996 DHS, only 4% of married women and 5% of married men reported using the method. Although condoms are rarely used within marriage or cohabiting partnerships, use is more common in extramarital relationships. Of the men who reported having had extramarital sex in the previous year, 52% had had one extramarital partner; 40% of these used a condom during the most recent sex with that partner. Forty-eight percent of men who reported having had extramarital sex in the last year had had two or more extramarital partners; of these, 39% had used condoms with their last two extramarital partners and were classified as condom users.

Men's knowledge of HIV and AIDS was high, with 99% claiming some knowledge; 90% knew that there is no cure, and 95% that the disease is transmitted through sexual contact (not shown). The most frequently mentioned ways to avoid AIDS were to use a condom (76% of men), have only one partner (17%) and reduce the number of partners (11%). Nine out of 10 respondents perceived that they had no or a small risk of acquiring HIV, and 41% reported that they had modified their behavior because of knowledge of AIDS. The most commonly reported changes were stopping extramarital sex (27%), decreasing the number of partners (8%) or using condoms (5%).

In bivariate analysis, men who were not affiliated with a religion were the most likely (19%) and evangelical men the least likely (3%) to have had an extramarital partner during the previous year (Table 1). A significantly greater proportion of men in northern Brazil than of men in the south had had an extramarital partner (22% vs. 7%). Extramarital relationships were also significantly associated with younger age, younger age at first sex, cohabitation, having been married more than once and not being the head of the household.

Among those who had had extramarital partners, those living in the north had a significantly greater mean number of partners (2.8), than did those in southern (1.7) or central (2.2) Brazil. Men who had had at least a primary school education had more partners, on average, than those who had not (2.8 vs. 2.0); men who were cohabiting had a greater mean number of partners than those who were married (3.1 vs. 2.1). Condom use with extramarital partners was significantly associated with living in southern or central Brazil, greater wealth, higher education, younger age and being in a first marriage.

In the multivariate analysis (Table 3), unaffiliated and Catholic men were significantly more likely than evangelicals to have had extramarital sex in the previous 12 months (odds ratios, 3.0-4.7). In addition, unaffiliated and Catholic men who had had extramarital sex reported 1.4-1.6 times as many extramarital partners as did evangelical men, and their odds of having had unprotected extramarital sex were 3.4-7.9 times as great.

Other characteristics also were found to be associated with extramarital sexual behavior. In comparison with men living in southern Brazil, those living in the north had increased odds of having had extramarital sex (3.1), having had a greater number of extramarital partners (1.5) and having had unprotected extramarital sex (3.8). Wealth was associated with having protected extramarital sex, with those whose household assets were valued at more than US$1,000 having 12 times the odds of using condoms with extramarital partners among those with household assets valued at less than US$300. Men with professional occupations were more likely than farmers or agricultural workers to have had extramarital sex (1.8), and men who had completed at least a primary school education had significantly more partners than those who had not.

Compared with men aged 40 or older, men who were younger than 30 had significantly increased odds of having had extramarital sex (1.6) and of having used condoms with extramarital partners (9.6); younger age at first sex was correlated with having had extramarital sex (1.5-2.7) and having had unprotected extramarital sex (2.0). Finally, cohabiting men had a greater number of extramarital partners than married men (1.4), and men who had had a previous marriage were more likely than those in their first marriage to have had extramarital sex (1.9) and to have done so without protection (2.3).

The data suggest that condoms were more commonly used with prostitutes or strangers than with friends or lovers. The confidence intervals of the estimates, however, are wide because of the small number of men (200) in the subsample, and the difference is not statistically significant. The large value of the random effects indicates significant unexplained variance in condom use.

We found no evidence that men who risk contracting HIV and other STIs by having extramarital partners were more likely than others to protect their wives by using condoms within marriage. In addition, men's number of extramarital partners was not significantly associated with their probability of using condoms within marriage (not shown). There was, however, a link between condom use inside and outside of marriage: Among men who used condoms with an extramarital partner in the last year, 8% also used condoms with their wife or cohabiting partner; among men who did not use condoms outside of marriage, none used the method with their wife or cohabiting partner.

DISCUSSION

Sexual behavior is difficult to study because of its private and sensitive nature, and because what people say and what they do may differ. Doubts about the reliability of reported behaviors abound and certainly apply to data from large-scale surveys that have not been designed specifically to study sexual behavior. Interpretation of DHS data must be cautious, especially as respondent veracity may vary between population subgroups. Results from sex surveys in the developed world, however, are encouraging in their plausibility and consistency,¹¹ and the broad verdict about similar surveys in developing countries is that the data quality is sufficiently high to merit serious analysis.¹² In addition to possible reporting bias, the nonresponse rate of 26% may also be a source of bias, to the extent that nonresponse is related to sexual conduct.

According to our findings, 12% of married or cohabiting men reported having at least one extramarital partner in the year before the DHS. This figure is similar to that reported in Mexico,¹³ and is about twice that reported in the United States or Europe.¹⁴ This suggests that the risk of a generalized HIV epidemic is greater in Latin America than in North America or Western Europe. However, extramarital relationships probably occur even more often in most African countries, where the proportion of men who report having had one or more extramarital partners in the last year is typically 20-50%.¹⁵

Regular use of condoms can greatly reduce the risk of STI transmission.¹⁶ It is clear from the DHS data that in Brazil, as in most countries, condoms are much more likely to be used outside of marriage than within marriage. At 4-5%, the prevalence of condom use by married or cohabiting couples in Brazil is almost identical to the world and Latin American averages.¹⁷ By contrast, this analysis suggests that in 1996, 39% of married men used condoms with all their extramarital partners. Condom use with nonregular partners is one of the key prevention indicators used by UNAIDS to monitor the progress of HIV control programs. Estimates are available for 31 countries,¹⁸ and even though such estimates include single men and therefore are not directly comparable with the estimates from this analysis, the level of condom use in Brazil appears to be similar to the levels in other countries in the same region for which data are available (e.g., Bolivia, Chile, Costa Rica and Mexico).

We found variations in the proportion of men reporting extramarital sex by religion, with evangelicals having a decreased likelihood of having extramarital partners when compared with others. There are no recent official statistics on the number of evangelicals in Brazil, but experts agree that the current growth is explosive.¹⁹ The growth of evangelical churches has been attributed to their high media profile, their focus on offering practical solutions to people's problems and their ability to provide social equality and increase social capital among disenfranchised Brazilians.²⁰ Surprisingly, we found little difference in occupation, household assets or education among religious groups, challenging the idea that evangelicals are drawn mainly from the lower socioeconomic groups.

The decreased likelihood of extramarital relationships among evangelicals is striking, and is consistent with their moral and devout image.²¹ Although the Catholic church stresses similar moral behavior, Brazilian Catholicism is a religion of birth rather than of conversion, which may be why Pentecostals appear to adhere more strictly to their moral codes. The evangelical church is growing rapidly in many developing countries,²² and other studies have also found that the sexual behavior of evangelicals differs from that of other religious groups.²³ We found that when condom use was taken into account, evangelicals' odds of having had unprotected extramarital sex in the previous year were as little as one-eighth those of others. A causal link cannot be proven. It may be that Pentecostals underreport extramarital sex or that sexually faithful men are more likely to convert to Pentecostalism than other men. We also do not know if behavior will remain unchanged if the numbers of evangelicals continue to grow. If joining the Evangelical church actually results in a change in sexual behavior, the growth of the religion could have a significant impact on HIV and AIDS in Brazil. If, however, its growth results in increased underreporting of risk behavior, interpretation of behavioral surveillance results will need to be made with special care.

The other predictors found to be significant in this analysis should not go unnoticed. We found striking variations in risk behavior by men's region of residence: Northerners were much more likely than men living in the south to report having had an extramarital partner and having had multiple extramarital partners, and they were no more likely to use condoms during their extramarital relationships. The net result is that men in the north had almost four times the odds of those in other regions to engage in unprotected extramarital sex. The north is the least developed region of Brazil, but as the regional difference remained even after adjustment for education, occupation and household wealth, it is unlikely that socioeconomic factors account for the behavioral differences.

Cultural differences between regions are strong and may offer a more plausible explanation. Machismo, an important value in Brazil, contrasts a masculine, virile and active male image to norms of femininity, motherhood, virginity and passivity in women.²⁴ Having multiple partners is a reflection of this male virility and is, thus, to some extent, sanctioned.²⁵ Northern men may conform more to this traditional notion of machismo than their southern counterparts.

Another important predictor of extramarital relationships and unprotected sex was age at sexual debut. A positive link between early debut and extramarital sex in later life has been found in other studies.²⁶ This association could result from reporting bias, with men who exaggerate the number of extramarital partners perhaps being more likely than others to report early sexual activity. An alternative explanation could be biological, with some males having persistently stronger sex drives than others. The origin may also be social: Because of family background and social networks, young men may be socialized into different codes of sexual conduct that persist and influence later sexual lifestyles. To the extent that this latter explanation is correct, the results here strongly endorse the importance of safe-sex interventions among young people to reduce the number of men who become habituated to sexual risk-taking.

Rural-urban differences in behavior were small, implying that HIV poses as big a threat in rural areas as in towns and cities; socioeconomic differentials in behavior were also not pronounced. Neither education nor household wealth was associated with the probability of extramarital sex or unprotected sex. Thus, HIV risks do not follow socioeconomic contours, but are similar across rich and poor, educated and less educated. The policy implications are clear: HIV-prevention efforts should address the entire adult population, particularly in the north, rather than attempt to identify and focus attention only on high-risk groups.