Prostitution among female street youths represents an important risk factor for several health problems. Little is known about the incidence and determinants of prostitution in this vulnerable population, and no data have been previously reported based on a longitudinal follow-up study. The objective of this study was to determine predictors of initiation into prostitution among female street youths. Female youths aged 14 to 25 years were enrolled in the Montreal Street Youth Cohort. They completed a baseline and at least one follow-up questionnaire between January 1995 and March 2000. Girls who reported never having engaged in prostitution at baseline were followed prospectively to estimate the incidence and predictors of prostitution. Of the 330 female street youths enrolled as of September 2000 in the cohort, 148 reported no history of involvement in prostitution at baseline and completed at least one follow-up questionnaire. Of these 148 girls, 33 became involved in prostitution over the course of the study (mean follow-up 2.4 years), resulting in an incidence rate of 11.1/100 person-years. Multivariate Cox regression analysis revealed having a female sex partner (adjusted hazard ratio [AHR] 3.8; 95% confidence interval [CI] 1.6–9.1) was an independent predictor of initiation into prostitution after controlling for having been on the street at age 15 years or younger (AHR 1.8, 95% CI 0.9–3.8), using acid or phecyclidine (PCP; AHR 2.0, 95% CI 0.9–4.6), using heroin (AHR 1.9, 95% CI 0.7–5.5), the use of drugs greater than twice perweek (AHR 1.9, 95% CI 0.9–4.2), and injection drug use (AHR 0.8, 95% CI 0.3–2.4). The incidence of prostitution in female street youths was elevated. Having a female sex partner was a strong predictor of initiating involvement in prostitution.

We compared sexual risk behaviors of men who have sex with men and inject drugs (MSM/IDU) with those of other men who have sex with men (MSM). Of 910 MSM surveyed, 106 (12%) injected drugs in the previous year. MSM/IDU were younger than MSM and more likely to be HIV-seropositive, Aboriginal, economically disadvantaged, engaged in the trade of sex for money or drugs, and to report having female sexual partners. MSM/IDU reported more casual sexual partners and in multivariate analyses were twice as likely to report unprotected receptive anal intercourse with casual partners. These results, combined with those from previous analyses, suggest that the higher risk for HIV seroconversion among MSM/IDU in this cohort is attributable mainly to sexual rather than injection-related exposures. Controlled assessments are needed to identify optimal sexual risk reduction strategies for MSM/IDU.

OBJECTIVE:To determine the incidence of pregnancy among active injection-drug users and to identify factors associated with becoming pregnant. METHODS:The Vancouver Injection Drug User Study (VIDUS) is a prospective cohort study that began in 1996. Women who had completed a baseline and at least one follow-up questionnaire between June 1996 and January 2002 were included in the study. Parametric and non-parametric methods were used to compare characteristics of women who reported pregnancy over the study period with those who did not over the same time period. RESULTS:A total of 104 women reported a primary pregnancy over the study period. The incidence of pregnancy over the follow-up period was 6.46 (95% confidence interval (CI) 5.24-7.87) per 100 person-years. The average age of women who reported pregnancy was younger than that of women who did not report pregnancy (27 vs. 32 years, p < 0.001). Women of Aboriginal ethnicity were more likely to report pregnancy (odds ratio 1.6, 95% CI 1.0-2.5). Comparison of drug use showed no significant differences in pregnancy rate with respect to the use of heroin, cocaine or crack (p > 0.05). In examining sexual behavior, women who reported having had a regular partner in the previous 6 months were three times more likely to have reported pregnancy. Despite the fact that 67% of women in this study reported using some form of contraception, the use of reliable birth control was low. Only 5% of women in our study reported the use of hormonal contraceptives. CONCLUSION:There were a high number of pregnancies among high-risk women in this cohort. This corresponded with very low uptake of reliable contraception. Innovative strategies to provide reproductive health services to at-risk women who are injecting drugs is a public health priority.

Objectives: To estimate HIV incidence and identify predictors of seroconversion among Montreal street youth. Methods: From 1995 to 2000, street youth aged 14–25 years were recruited in a prospective cohort study. Interviews were conducted semiannually and included anti-HIV antibody testing. Among subjects who tested HIV negative at study entry and were interviewed at least twice, predictors of HIV seroconversion were identified using Cox regression. Variables considered as potential predictors were age, sex, injection drug use, being a male reporting male sexual partners, and survival sex. Results: Overall, 1013 youth were recruited in the study. HIV prevalence at study entry was 1.4% [95% confidence interval (CI) 0.8–2.4] and was stable over the 6 recruitment years. Among the 863 subjects selected for the incidence analysis, 66.7% were boys, 47.2% had ever injected drugs at study entry, and 25.7% had ever engaged in survival sex. The selected participants cumulated 2327 person-years of follow-up and 16 HIV seroconversions were observed, for an incidence rate of 0.69 per 100 person-years (95% CI 0.39–1.11). In univariate analysis, injection drug use [hazard ratio (HR), 7.0] and involvement in survival sex (HR, 4.0) were associated with HIV incidence. In the multivariate analysis, only injection drug use was retained. Conclusions: Among Montreal street youth, injection drug use was the strongest predictor of HIV seroconversion. Prevention of initiation into injection drug use must become a public health priority.

Esterification of 1(2-nitrophenylazo)2,3-dihydroxynaphthalene and of 1(2-nitrophenylazo) 2,7-dihydroxynaphthalene and their methoxy and chloro derivatives with acryloyl chloride occurred at the 3- and 7-positions respectively and gave the acryloyloxyazo monomers in 40–63% yield. The acryloyloxy monomers were fully characterized by their infrared, ultraviolet and 1H and 13C NMR spectra. Their copolymerization with styrene was studied.

Recent whole-cell recordings show that there are multiple synaptic inputs to the accessory optic system of the pond turtle Pseudemys scripta elegans (the basal optic nucleus, BON), suggesting a complex role in visual processing. The BON outputs have now been investigated using transport of diI, rhodamine-conjugated and biotinylated dextrans. Although transport was primarily anterograde, contralateral retinal ganglion cells were labeled retrogradely, confirming that the injection site was a retinal target. Other retrogradely labeled neurons were found ipsilateral to the injection site, in the pretectum, the ventral tegmentum, the dorsal nucleus of the posterior commissure and the lateral habenular nucleus. However, other data indicate that the habenular cells were labeled by spread of the tracer from the BON to the adjacent fasciculus retroflexus and interpeduncular nucleus. Anterogradely labeled fibers projected from BON following three paths, a lateral bundle to the ipsilateral dorsal midbrain, an intermediate bundle to the ipsilateral pretectal area or the posterior commissure and a ventral fiber bundle to the tegmentum bilaterally. Some of these fibers projected caudally through the tegmentum and cerebellar peduncle to terminate just below the Purkinje cell layer of the cerebellar cortex. Fibers that coursed via the intermediate bundle to the posterior commissure were also seen reaching the contralateral pretectal area and the contralateral BON. Injections of the retrograde tracer Fluorogold were also made in the BON to confirm the reciprocal connectivity of both basal optic nuclei. The pathways revealed by these experiments indicate the existence of multiple afferent and efferent connections of the BON, supporting the view that the accessory optic system is more than a simple relay of retinal signals into the brainstem for optokinetic reflexes.

Men were followed prospectively to identify demographic and behavioural characteristics associated with HIV seroconversion. Thirty-six HIV cases were identified (HIV incidence 1.9/100 person-years). Unprotected receptive anal sex with HIV-positive partners and with casual partners regardless of serostatus was associated with seroconversion. Having ever been in prison or in a psychiatric ward were predictive of seroconversion. HIV prevention efforts should address issues related to mental and social stability and serodiscordant relationships to reduce the risk of seroconversion.

In Canada, very little is known about the factors and processes that cause drug-related harm among female intravenous drug users (IDUs). Women who inject drugs and participate in the survival sex trade are considered to be at increased risk for sexual and drug-related harms, including HIV infection. Between September 1999 and September 2000, women participating in the VIDUS cohort in Vancouver and the St. Luc Cohort in Montreal completed interviewer-administered questionnaires. Analyses were conducted to compare the demographic characteristics, sexual risk behaviours, risky injection practices and drug use patterns among women who self-identified as participating in the sex trade with those who did not identify as participating in the sex trade. Logistic regression was used to identify factors independently associated with exchanging sex for money or drugs. HIV prevalence at the study visit (September 1999-2000) was 29% for sex trade workers and 29.2% for non-sex trade workers. While patterns of sexual risk were similar, the risky injection practice and drug use patterns between sex trade workers and non-sex trade workers were markedly different. Logistic regression analysis of cross-sectional data revealed that independent behaviours associated with the sex trade included: greater than once per day use of heroin (adjusted OR 2.7), smokeable crack cocaine (adjusted OR = 3.3) and borrowing used syringes (adjusted OR = 2.0). Creative, client-driven interventions are urgently needed for women who trade sex for money or for drugs.

The objective of this study was to compare human immunodeficiency virus (HIV) risk factors among female street youths involved in prostitution and those with no history of prostitution. Youths aged 14 to 25 years were recruited into the Montreal Street Youth Cohort. Semiannually, youths completed an interviewer-administered questionnaire. Statistical analyses comparing characteristics and HIV risk factors for girls involved in prostitution and those never involved were carried out using parametric and nonparametric methods. Of the girls, 88 (27%) reported involvement in prostitution, and 177 girls reported no history of prostitution at the baseline interview. Girls involved in prostitution were two times and five times more likely to have reported bingeing on alcohol and on drugs, respectively. A history of injection drug use was four times more likely to have been reported by girls involved in prostitution. Further, these girls were 2.5 times more likely to have reported injected cocaine as their drug of choice. Girls involved in prostitution were younger the first time they had consensual sex and were twice as likely to have reported anal sex. Consistent condom use for anal, vaginal, and oral sex was low for all girls. Girls involved in prostitution reported more risky sexual partners. In conclusion, girls involved in prostitution may be at increased risk of HIV infection due to their injection drug use and risky sexual behaviors. Unique intervention strategies are necessary for reducing HIV infection among female street youths involved in prostitution.

The purpose of this study was to provide both a population estimate and a socio-economic and health profile of gay and bisexual men living with HIV/AIDS in a large Canadian urban centre. A random telephone survey was used to determine the number of men in the study area over the age of 20 identifying as gay or bisexual and to characterize their health and socio-economic status. Out of a total of 1,176 completed interviews, 300 males described themselves as gay or bisexual. Projecting this figure on recent census data we estimated the number of men identifying as gay or bisexual in this region of downtown Vancouver, BC, at 5,100. Among these men we found an HIV prevalence rate of 16%, with those who reported a positive serostatus being less likely to be employed full time and more likely to earn less than $20,000 per year. In terms of clinical characteristics, HIV-positive men had a median CD4 cell count of 397 cells/mm(3) and a median viral load of less than 500 copies/ml. Eighty-three per cent of the HIV-positive respondents were on antiretroviral therapy and the median number of drugs taken by these men was three. In summary, random surveys of populations affected by this epidemic are important for policy makers, clinicians and persons caring for those with HIV/AIDS as they paint a clearer picture of who is being affected and help to identify areas where increased services are needed.

Objective: To characterize longitudinal patterns of sexual behavior in a cohort of young gay and bisexual men and determine their reasons for not using condoms.Methods: Prospective data from a cohort of young gay and bisexual men aged 18 to 30 years were studied. Study participants had completed a baseline questionnaire and HIV test between May 1995 and April 1996 and four annual follow-up questionnaires.Results: A total of 130 HIV-negative Vanguard participants met the eligibility criteria for this analysis. The median age at baseline was 26 years (range, 24-28). Most were white (79%), had completed high school (85%), were currently employed (82%), lived in stable housing (95% and reported annual incomes of greater than or equal to $10,000 (82%). (All dollar amounts are given in Canadian dollars.) Consistently over the 5-year study period, > 70% of study subjects reported having greater than or equal to 1 regular male sexual partners in the previous year. During each of the five successive 1-year periods, between 34% and 40% of respondents reported having had unprotected receptive anal intercourse with regular partners. Slightly fewer individuals (between 29%-39%) reported having had unprotected insertive anal intercourse with regular partners. Between 13% and 25% of participants reported having had insertive unprotected anal intercourse with casual sexual partners; and between 9% and 18% reported having had unprotected receptive anal intercourse with casual sexual partners. Reasons for engaging in unprotected anal intercourse varied depending on type of sexual partnership.Conclusion: High-risk sexual behaviors remained fairly consistent over a 5-year period in this study. This suggests that it is critically important to understand the motivations for unprotected sex when designing and implementing programs aimed at reducing HIV risk among young gay and bisexual men.

With the explosive nature of the South African AIDS epidemic there is an urgent need for HIV prevention methods controlled by women. Because several microbicide trials are going on in South Africa and elsewhere there also is an urgent need to determine South African mens perceptions of and preferences for a potential vaginal microbicide. 243 men were recruited from three sites in South Africa: sexually transmitted disease (STD) clinics (N = 95) the general population (N = 98) and universities (N = 50). A brief demonstration of a potential vaginal gel microbicide was followed by a private interview which included questions about mens demographic characteristics sexual activities condom use and willingness to support their partners use of a vaginal product. The mean ages of men from STD clinics the general population and universities were 30 28 and 23 years respectively. 45% of men from STD clinics 69% from the general population and 65% of the university students reported a dislike for male condoms. More than 80% of the entire sample wanted their partner to be protected against HIV and other STDs. The majority of the men in the three groups (77-87%) would like their partner to use a microbicide and 66-82% said they would like to be involved in the decision to use a microbicide. Men were more likely to prefer a vaginal product that prevents HIV and STD transmission and does not act as a contraceptive that one that acts only as a contraceptive. The majority (58-67%) of men reported that excess lubrication was not a desired product characteristic. Vaginal microbicides may be acceptable to South African men. The amount of lubrication provided by the product and non-interference with sexual pleasure may be keys to product acceptability. Preference for an effective non-contraceptive microbicide was greater than for a contraceptive product. (authors)

Since the beginning of the HIV epidemic in north America, the majority of HIV infections have occurred among men who engage in sexual relations with other men. As the HIV epidemic enters its third decade, gay and bisexual men continue to have among the highest rates of HIV infection. Previous studies have highlighted the decline in the incidence of HIV and risk behaviour among gay and bisexual men. However, several studies have suggested that young gay and bisexual men continue to engage in unprotected sexual behaviours and are at continued risk of HIV infection. Recent reports in the media and research literature have indicated an increase in the incidence of HIV among gay and bisexual individuals in many of the world's major cities. The purpose of this study was to determine trends in HIV incidence using data from a prospective cohort of young gay and bisexual men.

The successful use of antiretroviral therapy for post-exposure prophylaxis (PEP) in cases of accidental and occupational exposures has prompted researchers, clinicians and public health decision makers to ask whether PEP would be effective in cases of sexual exposures. Although the answer to this question remains unknown, some factors that need to be considered have been identified. These include: the frequency of exposure, the probability of knowing the HIV status of the source, the elapsed time between exposure and possible intervention, and the impact PEP may have on risk reduction behaviours. In addition, given the limited resources available for the management of HIV disease, the cost of PEP will play a certain role in deciding its future. Other studies [1–3] have investigated whether using PEP for sexual exposures to HIV is effective. Pinkerton et al. [3] conducted an in-depth cost–utility analysis, and concluded that PEP should be recommended to partners of infected persons, to patients reporting unprotected anal intercourse, and possibly in cases in which there is a substantial likelihood that the partner is infected. In terms of clinical practice, no consensus has been established among physicians on the use of PEP for non-occupational exposures. Although some physicians are reluctant to prescribe antiretroviral prophylaxis, others appear to have a favourable attitude towards the prescription of PEP for sexual exposures [4] For example, in San Francisco, CA, USA, two clinics have recently opened and are currently providing anti-HIV prophylaxis after high-risk sexual exposures [5,6] In the light of the uncertainty surrounding this issue and its possible implications, leading commentators in the area have made a call for the development of rational guidelines [4,7] The following cost analysis is a step in this direction because the wise allocation of scarce resources is an integral part of any HIV management strategy. Although a few economic analyses have been conducted, no studies have investigated how much it would cost to provide PEP to a known at-high-sexual-risk population. The purpose of our study was to determine the cost of providing post-exposure prophylaxis to the male gay and bisexual community at high sexual risk of contracting HIV in the West End of Vancouver, British Columbia, Canada. A cost estimate was obtained by multiplying the cost of antiretroviral prophylaxis per course by the number of gay and bisexual men at high sexual risk and by the number of risk incidents per person per year. To determine how many men were at high risk, responses on a self-administered questionnaire given to a prospective cohort of gay and bisexual men beginning in May 1995 were used. High sexual risk was defined as having at least one episode of unprotected anal sex (insertive or receptive) with a casual male partner in the previous year, or having at least one episode of unprotected anal sex (insertive or receptive) with an HIV-positive man in the previous year. The proportion of men in the West End who identified themselves as either gay or bisexual was derived from a random telephone survey, and the cost of a course of PEP was taken from the British Columbia Centre for Excellence in HIV/AIDS Drug Treatment Program. Monte Carlo methods were used to simulate confidence limits around the cost estimate. Out of an estimated total of 5100 (95% confidence interval: 4700–5400) gay and bisexual men in Vancouver's West End, 1391 (27.3%) were classified as being at high risk of contracting HIV through unsafe sexual behaviours on the basis of prospective cohort data. The average number of risk incidents per person per year was three (0–6) and, depending on the recommended regimen, stavudine and lamivudine or triple therapy with nelfinavir, the average cost of PEP varied from Can$530 to 903 with an average price of Can$560. On the basis of these assumptions and the Monte Carlo simulation, the potential cost of making post-exposure prophylaxis available to all those at high sexual risk in the West End was estimated to be Can$2 259 780 (95% confidence interval: Can$800 000–4 100 000). The above minimum cost estimate, Can$800 000 per annum, for providing PEP to at-risk gay and bisexual men in Vancouver's West End is approximately equal to British Columbia's current budget for all accidental exposures in the province. This is an important fact considering the limited resources available to fight HIV disease and Canada's universal healthcare system. In light of the numerous uncertainties regarding the effectiveness of PEP for sexual exposures, the growing cost of providing anti-HIV therapy for confirmed positive individuals, and the potential cost of expanding the use of PEP to include high-risk consensual sex, we feel that other preventative strategies should take priority. Future research in this area is needed so that clinicians, researchers, policy makers and HIV-positive persons can gain a better sense of the issues surrounding and the implications of making PEP available for sexual exposures. Sophie Low-Beer Amy E. Weber Kim Bartholomew Monica Landolt Doug Oram Julio S. G. Montaner Michael V. O'Shaughnessy Robert S. Hogg

Background: This study was initiated to evaluate the demographic and clinical determinants of admission to hospital among HIV-positive men and women receiving antiretroviral therapy in British Columbia.Methods: The analysis was restricted to participants enrolled in the HIV/AIDS Drug Treatment Program between September 1992 and March 1997 who had completed an annual participant survey, had a viral load determination and had signed a consent form allowing electronic access to their inpatient hospital records. A record linkage was conducted with the BC Ministry of Health to obtain all records of hospital admissions from April 1991 to March 1997. Statistical analyses were carried out using parametric and nonparametric methods and multivariate logistic analyses.Results: The study sample comprised 947 participants (859 men, 88 women). Of these, 165 (17%) were admitted to hospital during the study period from May 1, 1996, to Mar. 31, 1997. The median number of admissions was 1 (interquartile range [IQR] 1-2 admissions), and the median length of stay per admission was 3 days (IQR 1-8 days). Admission to hospital was associated With being unemployed (82% of those admitted v. 58% of those not admitted), being an injection drug user (24% v. 17%), reporting a fair or poor health status (46% v. 29%) and having a physician experienced in the management of HIV/AIDS (31% v. 24%). Examination of clinical determinants demonstrated that hospital admission was associated with a previous admission (72% v. 46%), a high viral load (median 74 000 v. 14 000 HIV-1 RNA copies/mL), a low CD4 count (median 0.16 v. 0.27 x 10(9)/L) and an AIDS diagnosis (44% v. 24%). Multivariate logistic regression analysis revealed that being admitted to hospital was independently associated with being unemployed (odds ratio [OR] 2.64, 95% confidence interval [CI] 1.66-4.20), having been previously admitted to hospital (OR 2.30, 95% CI 1.53-3.46), having a high viral load at baseline (OR 1.45, 95% CI 1.16-1.80), being an injection drug user (OR 1.63, 95% CI 1.02-2.62) and having an experienced physician (OR 1.98, 95% CI 1.29-3.03).Interpretation: Hospital admission among participants in this study Was found to be associated with marginalization and poor health status.

OBJECTIVE:To compare sexual behavior data obtained using a weekly-recall questionnaire, a daily-recall questionnaire, and a coital diary.DESIGN:Cross-sectional survey of female sex workers from KwaZulu-Natal, South Africa between August and October 1998.METHODS:In this study, 52 weekly-recall questionnaires, 27 daily-recall questionnaires, and 79 coital diaries for dates corresponding to the questionnaires were obtained from female sex workers. Variables examined included: number of clients, number of condoms used with clients and partners, and number and type of sexual acts with clients and partners. Statistical analyses were conducted to examine the degree of agreement between the data collection methods and to assess differences between the mean values of the variables in the questionnaires versus the diary.RESULTS:Comparison of weekly-recall questionnaires with coital diaries indicated a significantly greater mean number of clients (P < 0.001), number of condoms used (P < 0.001), vaginal acts (P < 0.001), and anal acts (P = 0.044) reported in the diary versus the questionnaire. On comparison of daily-recall questionnaire with coital diary, significant differences were revealed between the means detected for the number of clients (P = 0.027), number of days worked (0.009), and anal acts with clients (P = 0.004).CONCLUSIONS:The use of coital diaries for the collection of sexual behavior data may be limited to cross-sectional community surveys. A recall questionnaire may provide more reliable and a better quality of data for longitudinal studies and for human immunodeficiency virus/sexually transmitted disease evaluation programs.

OBJECTIVE:To assess the impact of HIV/AIDS on hospitalization and mortality patterns in Canada.METHODS:Hospitalizations and deaths due to HIV/AIDS were compared with select causes of morbidity and mortality among men and women across provinces, regions and select cities between 1987-94. Patterns of hospitalization and mortality were characterized by calculating age-specific, standardized rates, rate ratios and potential years of life lost before 65 years.RESULTS:A total of 28,462 hospitalizations (26,153 in men and 2,309 in women) and 8,739 deaths (8,192 in men and 547 in women) were attributed to HIV/AIDS during the study period. Rates of HIV/AIDS hospitalization were highest for men in Ontario, Quebec and British Columbia, and in Montreal, Toronto and Vancouver; while among women they were highest in Quebec and in Montreal, Toronto and Vancouver. Mortality rates followed a pattern similar to the rates found for hospitalization.CONCLUSIONS:Our analysis reveals the considerable impact of HIV/AIDS on patterns of morbidity and mortality in Canada.

To estimate the potential direct cost of making triple combination antiretroviral therapy widely available to HIV-positive adults and children living in countries throughout the world.For each country, antiretroviral costs were obtained by multiplying the annual cost of triple antiretroviral therapy by the estimated number of HIV-positive persons accessing therapy. Per capita antiretroviral costs were computed by dividing the antiretroviral costs by the country's total population. The potential economic burden was calculated by dividing per capita antiretroviral costs by the gross national product (GNP) per capita. All values are expressed in 1997 US dollars.The potential cost of making triple combination antiretroviral therapy available to HIV-positive individuals throughout the world was estimated to be over US$ 65.8 billion. By far the greatest financial burden was on sub-Saharan Africa. The highest per capita drug cost in this region would be incurred in the subregions of Southern Africa (US$ 149) followed by East Africa (US$ 116), Middle Africa (US$ 44), and West Africa (US$ 42). In the Americas, subregional data indicated the highest per capita drug cost would be in the Latin Caribbean (US$ 22), followed by the Caribbean (US$ 17), Andean Area (US$ 7), the Southern Cone (US$ 6), North America (US$ 6), and Central American Isthmus (US$ 5). In Asia and Europe the percentage of the GNP necessary to finance drug therapy was less than 1% in most countries examined.Our results demonstrate that the cost of making combination antiretroviral therapy available worldwide would be exceedingly high, especially in countries with limited financial resources.In 1997, an estimated 5.8 million people worldwide were infected with HIV, of whom 90% lived in developing countries, especially in sub-Saharan Africa. While antiretroviral therapy has been shown to prolong survival in people with HIV/AIDS, many of the countries with the highest rates of HIV infection have little or no access to antiretroviral therapy, for a number of reasons, including cost. Findings are presented from a study conducted to estimate the potential direct cost of making triple combination antiretroviral therapy widely available to all of the world's HIV-infected population. The potential cost of making such therapy available to HIV-positive people worldwide was estimated to be over US$65.8 billion, in 1997 US dollars, with the greatest expenditures needed in sub-Saharan Africa. The highest per capita drug cost in sub-Saharan Africa would be incurred in Southern Africa (US$149), followed by East Africa (US$116), Middle Africa (US$44), and West Africa (US$42). In the Americas, per capita drug costs would be US$22 in the Latin Caribbean, US$17 in the Caribbean, US$7 in the Andean Area, US$6 in the Southern Cone and North America, and US$5 in the Central American Isthmus. In Europe and Asia, the percentage of GNP needed to finance drug therapy was less than 1% in most countries examined. For each country, antiviral costs were determined by multiplying the annual cost of triple antiretroviral therapy by the estimated number of HIV-positive people accessing therapy. Per capita therapy costs were calculated by dividing the antiretroviral costs by the country's total population. The potential economic burden was calculated by dividing per capita antiretroviral costs by the gross national product (GNP) per capita.