REPORTS OF THE PROPHYLACTIC use of antibiotics as a preventive measure against sexually transmitted diseases (STD) by commercial sex workers (CSW) have appeared periodically in the literature and have been noted in passing by researchers studying pharmaceutical behavior in less developed countries.1–6 Left unexamined is when, how, and which antibiotics are used by CSW, in what context, and with what sense of perceived efficacy. In addition, little is known about condom use among users of prophylactic antibiotics. Also in need of investigation is the extent to which those using antibiotics as a prophylactic against STD consider this an effective means of protecting themselves against acquired immunodeficiency syndrome (AIDS).
A knowledge, attitude, and practice, or KAP, study of high‐risk behavior associated with STD and AIDS was carried out in Cebu City, Philippines in 1992.7 During this study, informants were questioned as to whether antibiotics were an effective prophylactic against STD. Between 19% and 36% of four convenience samples of registered and unregistered CSW, men having sex with men, and male STD patients reported that antibiotics were useful in preventing sira, the Cebuano term encompassing a wide range of STD. Notably, unregistered CSW reported the highest rate of familiarity with antibiotic prophylaxis. Table 1 summarizes findings from this study.
In this article, we examine in greater detail CSW perceptions and practices related to antibiotic prophylaxis in Cebu City, the second largest city in the Philippines. Cebu is a port city undergoing rapid social change and population growth as a result of the creation of a free trade zone and expanded international tourism facilitated by improved transportation. Perceptions and practices related to prophylactic antibiotic use for STD and AIDS are examined among CSW working in four different work environments.
A survey instrument was developed and pretested after 3 months of intensive ethnographic research on popular perceptions of STD‐AIDS and practices related to the prevention of these diseases in Cebu. A 144‐item questionnaire was administered orally by trained Filipino investigators to informants with an assurance of confidentiality. Each survey took approximately 45 minutes to complete. Data were coded and entered into Epi Info (version 6). This software package also was used for data analysis. This article reports on the portion of the survey that focused on antibiotic use for the prevention and self‐treatment of STD by commercial sex workers.
Three thousand women ranging in age from 18 to 35 years work in the Cebu City hospitality sector and are registered with the Cebu City social hygiene clinic. Most, but not all, of these women engage in prostitution at one time or another. All female employees in the hospitality sector are required by law to have a weekly checkup, during which time they receive a cervical gram stain that detects gram‐negative or gram‐positive bacteria, including gram‐negative diplocci presumed to be Neisseria gonorrhea. Every 6 months, they undergo blood testing for syphilis, hepatitis B, and human immunodeficiency virus (HIV). On the basis of pilot research carried out in 1992, it was estimated that the frequency of CSW who used antibiotics for STD prophylaxis was 20% ± 10%. Given a clinic population of 3000 female hospitality workers, a sample of 106 was required at the 99% confidence interval to make any generalizations about the population as a whole.
A multistage sampling procedure was followed to ensure that CSW from four distinct work environments would be represented. Work establishments were classified on the basis of the cost of alcoholic beverages sold and services provided as high‐class casas (houses of prostitution), high‐class bars (massage parlors, and so on) and low‐class establishments. After the classification of 108 hospitality establishments registered with the city health office, random samples of 40 CSW from 18 to 28 years of age were selected from each work environment list constructed. Commercial sex workers who had gonorrhea in the past year were removed from the work environment lists and treated as a separate sample who had more contact with the clinic doctor. Of a possible pool of 43 CSW 19 to 28 years of age with a history of gonorrhea, 40 were located and interviewed. An additional convenience sample of 40 freelance (unregistered) CSW, 15 to 28 years of age, working the streets or in illegal, low‐class casas were sampled. In total, 200 CSW were interviewed between July 1994 and April 1995. Of these 200 CSW, all were sexually active, but only 160 had engaged in sex with customers in the 2 weeks before the interview. It is this subsample of 160 CSW that is the central focus of this article.
Table 2 summarizes the characteristics of the 160 active CSW and the environments in which they work. Those CSW with histories of gonorrhea are grouped according to their routine work environment in Table 2 but are examined as a separate group when considering preventive health behavior involving antibiotic prophylaxis. The median age of registered CSW working in different work sites was 22 to 23 years, in contrast to the median age for freelancers, which was only 18 years old. Seventy‐five percent or more of registered CSW had at least a high school education, whereas only approximately 50% of freelancers had more than an elementary school education. Also notable, freelancers had sex with a median of 10 clients per week, whereas all categories of registered CSW (regardless of median weekly income) had a median of three customers per week. Between 58% and 74% of CSW had children to support. Only 3% of CSW had husbands, but 16% reported having live‐in boyfriends, and another 48% had boyfriends they saw regularly.
Familiarity with prophylactic antibiotic use for the prevention of STD was documented during the pilot phase of the study. Forty registered CSW, 20 of whom worked in high‐class establishments and 20 in low‐class establishments, were asked to look though a deck of cards containing the descriptions of 30 actions identified as useful in preventing STD during ethnographic research. When asked to select cards denoting actions they were familiar with, approximately half the informants selected cards related to antibiotic use:
Antibiotics after sex prevent sira (48%).
Antibiotics before sex prevent sira (40%).
Taking antibiotics now and then prevents you from getting sira (58%).
The 160 CSW who had sex with customers in the past 2 weeks were asked whether they had ever used antibiotics as a prophylactic against STD and whether they had used antibiotics for this purpose in the last two weeks. In response to having ever used antibiotics for STD prophylaxis, 20% of the sample of 160 CSW reported that they did so occasionally, and another 18% stated that they did so routinely. Among occasional and routine users, 24% reported using prophylactic antibiotics after having sex with each customer, 9% before having sex, and 4% before and after having sex. Fifteen percent reported taking antibiotics for prophylaxis two or three times a week, 6% reported taking it once a month, and 31% reported taking it when they felt as though they were coming down with an illness. This body state was left unspecified but was distinct from manifest symptoms associated with the actual occurrence of STD. Thirty‐one percent of the 160 CSW reported that they had taken an antibiotic at least once during the past 2 weeks to reduce their chance of getting an STD. Table 3 lists those antibiotics preferred for prophylaxis against STD by CSW. The median number of antibiotic pills or capsules taken for prophylactic purposes was one per treatment event. Table 4 summarizes data collected on antibiotic prophylaxis among the 160 CSW who reported having sex with a customer in the past 2 weeks.
Differences in occasional and regular prophylactic antibiotic use were not found to be statistically significant with regard to a CSW's place of origin (rural or urban), level of education (above or below high school), age (younger or older than 22 years), and whether the CSW had a child. Significant differences emerged when rates of CSW ever using antibiotics were examined in relation to work site. Among registered CSW having a customer in the past 2 weeks (n = 120), those working in a high‐class casa were twice as likely to have used an antibiotic for prophylaxis as were all other registered CSW (odds ratio (OR), 2.48; 95% confidence interval (CI), 1.03 to 6.03). Unregistered CSW (N = 40) reported much higher rates of prophylactic antibiotic use than registered CSW. Sixty‐three percent of freelance CSW reported regular (40%) or occasional (23%) antibiotic use compared to 29% of registered CSW reporting occasional (19%) or routine (10%) use. For those CSW who have ever taken prophylactic antibiotics, freelancers were four times more likely than registered CSW to have done so (OR, 3; 95% CI, 1.75 to 9.0).
An analysis of reported use of antibiotics as STD prophylaxis during the past 2 weeks revealed no significant differences between the 160 CSW based on place of origin, age, or whether they had a child. Also not statistically significant was having a history of gonorrhea during the previous year. Those CSW taking prophylactic antibiotics were twice as likely to have had an elementary school education as a high school education or above (OR, 2.3; 95% CI, 1.01 to 5.30). Education was associated closely with CSW registration. Most CSW with only elementary educations were unregistered freelancers.
The major difference between users and nonusers of prophylactic antibiotics in the past 2 weeks was work environment and registration with the Cebu City social hygiene clinic. Although no significant differences were found between groups of registered CSW, significant differences were found between registered and unregistered freelance CSW. Those taking antibiotics were five times more likely to have been unregistered freelance CSW as registered CSW (OR, 5; 95% CI, 2 to 10).
Antibiotic use was examined in relation to the number of customers CSW serviced per week and mean amount of money received per transaction. Those CSW who had sex with more than seven customers per week were four times more likely to have taken prophylactic antibiotics as were CSW seeing fewer than this number (OR, 3.54; 95% CI, 1.31 to 9.66). Unregistered CSW and those working in low‐class bars receive smaller fees from customers for sexual services than other CSW. The amount of payment per customer did not influence antibiotic use. Commercial sex workers who tended to have sex with customers paying less than the sample median of 500 pesos ($20) were no more likely to have used prophylactic antibiotics during the past 2 weeks than CSW receiving higher fees.
Prophylactic antibiotic use was next examined in relation to condom use. An issue demanding investigation was whether users of antibiotics were any less likely to use condoms with most of their customers. As a group, CSW used condoms with a median of 80% of their customers. We compared CSW who reported using condoms with 8 or more of their last 10 customers (69%) with those who used condoms with <8 of their customers (31%). As shown in Table 5, those CSW who had not taken antibiotics as prophylaxis during the past 2 weeks were three times more likely to have used condoms with 80% or more of their customers (OR 2.69; 95% CI, 1.21 to 6.04). As shown in Table 6, freelancers were seven times less likely to use condoms than all other CSW with 80% or more of their customers (OR 7.4 95% 3.02 to 18.3). Freelancers were also three times less likely to use a condom with a regular (suki) customer than were registered CSW (OR, 2.6; 95% CI, 1.15 to 5.97).
The 160 CSW were asked if they had ever self‐treated an ailment they feared might be a STD (sira) with antibiotics before seeing a doctor. As noted in Table 4, the percentage of freelancers using antibiotics for this curative purposes was more than twice that of registered CSW in any of the work environments examined. In all, 26% of CSW reported having self‐medicated suspected STD with antibiotics. Notably, those who reported self‐treating an ailment thought to be an STD were 14 times more likely to have used antibiotics as a prophylactic against STD in the past 2 weeks (OR, 14.14; 95% CI, 5.38 to 38.19). Self‐treaters of STD tended to use the same antibiotics they used for preventive purposes (Table 3).
Ethnographic research revealed that some CSW maintained a doubt as to whether STD were ever cured or whether they merely were controlled by medicines, remaining latent in the body until provoked. When the entire sample of 200 CSW was asked about this issue, 63% stated that STD were cured by medicines, 11% that STD were only controlled by medicines, and 25% expressed uncertainty. Of those 160 CSW engaging in sex with customers in the past 2 weeks, there was no statistically significant difference between those who thought STD could be cured by medicines and those expressing doubt about a cure.
Ethnographic research also revealed that CSW were unsure as to whether women with STD could be asymptomatic. When the entire sample of 200 CSW were asked whether a person could have a STD or AIDS (HIV) without symptoms, 38% responded yes, 8% said no, and 54% were unsure. No statistically significant difference was found between perceptions of the symptomatic nature of STD infection among those who did and did not have a reported history of sira. Prophylactic antibiotic use was examined in relation to ideas maintained by CSW about the symptomatic and asymptomatic nature of STD and AIDS. When antibiotic use of those 160 CSW having a customer during the past 2 weeks was scrutinized, no statistically significant difference in antibiotic use was found between those CSW who thought a woman infected with STD always manifested symptoms and those CSW who expressed doubt that this was always the case.
The sample of 200 CSW were asked whether they thought taking antibiotics would protect them against AIDS if they “had a doubt about a customer.” Although only 18% strongly felt antibiotics would protect them, another 34% stated that antibiotics might help prevent them from getting AIDS. Notably, a higher percentage of informants (52%) thought taking prophylactic antibiotics might be more useful in preventing AIDS than STD. When we questioned the sample of 200 CSW whether they thought that antibiotics were effective in preventing STD, only 29% expressed confidence in this practice, and another 8% suggested that taking antibiotics might be effective. Notably, 73% of users of prophylactic antibiotics in the past 2 weeks stated that taking these drugs was effective in preventing STD, and another 19% stated that they might be effective. There was no statistically significant difference between CSW with and without a history of gonorrhea with respect to their perceptions about the efficacy of antibiotics in preventing either STD or AIDS.
We asked the 160 CSW who had sex with customers during the past 2 weeks what they thought their chances were of becoming infected with an STD in the next year and with AIDS if they continued to work as CSW. These data are summarized in Table 7.
Perceived risk for infection with an STD and with AIDS was next examined in relation to prophylactic antibiotic use during the past 2 weeks. There was no statistical significance found between antibiotic use and perception of risk for both STD and AIDs in any category shown in Table 7.
A final issue examined was the commonality of taking prophylactic antibiotics before or after having sex with boyfriends or husbands when it was suspected that they were having sex with another woman. Fifty percent of the sample of 200 CSW reported that they suspected their partner was unfaithful, an estimate which is likely to be low given the sensitivity of the question. Concern about infidelity was also documented in response to a series of questions about reported episodes of STD. Fifty‐eight percent of CSW reported that they had experienced an STD since becoming a hospitality girl. Notably, 29% of these CSW identified their boyfriends or husbands as the cause of their illness.
Condom use with boyfriends and husbands was reported to be low, with only 27% of CSW reporting ever using condoms with their partners for any reason. Ethnographic research found that nonuse of condoms was a means of establishing trust in noncontractual sexual relationships and that introducing condom use carried with it high social cost to often fragile relationships. Even among those CSW expressing a doubt about the fidelity of their partners, only 26% reported condom use at any time. When these women were asked whether they thought their partners used condoms when having sex with other women, only 7% said yes, 42% said no, and 39% expressed a doubt that their partners would use condoms.
Antibiotic prophylaxis was explored as a means of reducing risk for STD infection from a partner. Despite widespread familiarity with antibiotics, only 15% of CSW reported taking antibiotics as a means of protecting themselves against infection from their boyfriends or husbands. To this group may be added those CSW who periodically take antibiotics (weekly, monthly) to protect themselves against STD from all sources of contagion.
Popular use of antibiotics as a prophylaxis against STD among CSW is commonplace in the Philippines. Among CSW in Cebu, patterns of prophylactic antibiotic use vary more by work environment than by such other factors as age, education, rural‐urban origin, or having a child. Unregistered freelance CSW are five times more likely to use prophylactic antibiotics and seven times less likely to use condoms with 80% or more of their customers than were all registered CSW. They also service three times the median number of customers a week than do other CSW. These women are least likely to have contact with doctors and to undergo routine gynecologic examination. Use of prophylactic antibiotics by these women offers them a false sense of security in a competitive work environment in which they have to hustle to survive, rendering them less likely than other CSW to refuse to have unprotected sex with customers. Given that a majority of their customers are Filipino and that many Filipino men are not predisposed to use condoms, the act of taking antibiotics constitutes one of the only preventive health measures these women feel they can undertake when they perceive themselves at risk.
Two issues may be raised beyond the obvious point that self‐treatment with one dose prophylactic antibiotics do not protect against STD and impede STD screening efforts.8 First, an alarming percentage of CSW interviewed considered antibiotics as potentially valuable in protecting them from the threat of AIDS. Second, given the high rates of antibiotic resistance reported in the Philippines, the irrational taking of such valuable antibiotics as rifampicin (central to short‐course tuberculosis therapy) is cause for grave concern.
Carefully designed studies of popular use of antibiotics for preventive health purposes are a health research priority. Although prophylactic antibiotic use by CSW has been reported in the literature, specific research has not been conducted on this form of popular health behavior. This study illustrates how this behavior may be investigated by teams of social scientists and epidemiologists. The findings of this study suggest that STD‐HIV interventions must address existing patterns of antibiotic prophylaxis.