Male circumcision and Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis: observations after a randomised controlled trial for HIV prevention.

OBJECTIVE: To assess the association between male circumcision and Neisseria gonorrhoeae, Chlamydia trachomatis and Trichomonas vaginalis using data from a male circumcision randomised controlled trial. METHODS: We used data collected during the male circumcision trial conducted in Orange Farm (South Africa) among men aged 18-24 years. Altogether, 1767 urine samples collected during the final follow-up visit were analysed using PCR. Prevalence of N gonorrhoeae, C trachomatis and T vaginalis was assessed as a function of male circumcision using odds ratios (OR) given by univariate and multivariate logistic regression. RESULTS: In an intention-to-treat analysis, prevalence of N gonorrhoeae, C trachomatis and T vaginalis among intervention and control groups were 10.0% versus 10.3% (OR 0.97; p = 0.84), 2.1% versus 3.6% (OR 0.58; p = 0.065) and 1.7% versus 3.1% (OR 0.54; p = 0.062), respectively. The association between T vaginalis and male circumcision remained borderline when controlling for age, ethnic group, number of lifetime partners, marital status, condom use and HIV status (AOR 0.48; p = 0.069). In the as-treated analysis, this association became significant (OR 0.49, p = 0.030; AOR 0.41, p = 0.030). CONCLUSIONS: This study demonstrates for the first time that male circumcision reduces T vaginalis infection among men. This finding explains why women with circumcised partners are less at risk for T vaginalis infection than other women. The protective effect on T vaginalis is an additional argument to recommend male circumcision in Africa where it is acceptable.

[A prospective study of antibiotic prescribing in an emergency care unit]. / Evaluation de la qualité des prescriptions d'antibiotiques dans le service d'accueil des urgences d'un CHU en région parisienne.

OBJECTIVE: The aim of the study was to assess the quality of the initial prescription of antibiotics in an emergency care unit (ECU). DESIGN: A two-week prospective observational study was performed in the ECU Ambroise-Paré covering all patients that were given antibiotic prescriptions. The antibiotic treatments were reviewed by medical experts and confronted with the recommendations of the local guide to antibiotic protocols (referential). Treatments were considered appropriate if indication, choice of the molecule, and route of administration complied to protocols; unacceptable if the indication or the choice of antibiotic was incorrect; debatable in all other cases. RESULTS: One hundred and four patients were reviewed over the two-week period. Treatments were prescribed mainly for urinary infections (31 cases), pulmonary (26) or cutaneous (23). In 84.5% of cases, indication was present in the referential. Beta-lactams accounted for 60% of prescriptions, followed by fluoroquinolones (32.5%). By combining three criteria (indication, choice and route of administration), only 54% of prescriptions were considered appropriate, 31% were debatable, and 15% unacceptable. Analysis showed that the quality of antibiotherapy was significantly better if the prescriber was informed about the inquiry and if the indication was present in the guidelines. CONCLUSION: The antibiotherapy manual is an indispensable tool for prescribers in the ECU, but it is insufficient to guarantee the quality of antibiotic prescriptions. Training sessions must be set up for emergency doctors, and the intervention of an infectious diseases specialist, as well as discussions about repeated clinical audit results, should enable a better use of antibiotics in the emergency unit.

[Evaluation of amoxicillin-clavulanic acid prescriptions in a teaching hospital of Parisian suburb]. / Evaluation des prescriptions d'amoxicilline-acide clavulanique dans un CHU de la région parisienne.

OBJECTIVE: Prospective study of amoxicillin-clavulanic acid (amox-clav) prescriptions in the medical departments of a teaching hospital that prescribes this antibiotic very often. DESIGN: From April to May 2004, each patient treated by amox-clav was included. Data were collected (age, sex, past diseases, associated-diseases, reason for hospitalization, prior antibiotic therapy, date of amox-clav prescription, indication for amox-clav prescription, other associated antibiotics, nosocomial or community-acquired infection, site of infection, bacteriologic samples and bacterial identification, treatment duration and status of the physician). Data were analysed by a muldisciplinary group and compared with a referential used for antibiotic prescriptions in our hospital. RESULTS: One hundred and two medical files were analysed. Seventy-one percent of amox-clav prescriptions were in adequation with the referential. Combination of three criteria (indication of antibiotic therapy, choice of amox-clav and of an antibiotic combination) showed that 58 (57%) was acceptable, 29 (28%) was debatable and 15 (15%) was unacceptable. Unacceptable prescriptions were often made by a junior. The majority of inadequate antibiotic prescriptions referred to acute pulmonary infections. Antibiotic combinations were often inadequate and treatment duration was too long. The quality of the prescription was more accurate when made by a senior. CONCLUSION: An effort should be made in our teaching hospital to optimize antibiotic prescriptions.

Modelling the impact of alternative HIV intervention strategies in rural Uganda.

OBJECTIVE: To assess the likely impact on HIV incidence of increased condom use, a reduction in casual sexual partners, treatment programmes for other sexually transmitted diseases (STD) and combinations of these in rural Uganda. METHODS: A simulation model for the transmission dynamics of HIV infection and STD was employed, drawing on data from a rural population cohort in South-West Uganda with an HIV prevalence of 9% among adults in 1990. RESULTS: For the scenario most consistent with data from the study population, 39% of all adult HIV infections were averted, in the 10 years from 1990, when condoms were used consistently and effectively by 50% of men in their contacts with one-off sexual partners (such as bar girls and commercial sex workers). Reducing by 50% the frequency of men's sexual contacts with one-off partners averted 68% of infections. Reducing by 50% the duration of all STD episodes averted 43% of infections. Combining these three interventions averted 82% of all adult infections in the 10 years from 1990. CONCLUSION: A substantial proportion of HIV infections may be averted in general populations through interventions targeted only on less regular sexual partnerships.

PIP: Simulation modelling was used to improve understanding of the transmission of human immunodeficiency virus (HIV) and other sexually transmitted diseases (STDs) in rural Uganda and assess the effectiveness of various preventive interventions. Each individual in the simulated population was represented by a set of characteristics (e.g., age, sex, HIV and STD status, type of sexual relationship, identity of all sexual partners) existent in a rural population cohort in South West Uganda in 1990 with an adult HIV prevalence rate of 9%. HIV transmission per sexual contact was assumed to be enhanced 10-fold (low co-factor scenario) or 100-fold (high co-factor scenario) during episodes of ulcerative STD. Even under the high co-factor conditions, 50% condom use resulted in a 39% reduction in HIV over 10 years. A 50% reduction in the frequency of sexual contacts with one-off partners (e.g., prostitutes) averted 68% of infections. When the duration of all STD episodes was reduced by 50%, 43% of infections were averted by the year 2000. If all three of these interventions were combined, 82% of HIV incidence was averted by the year 2000. These findings suggest that a substantial proportion of HIV disease can be prevented through interventions that target only casual sexual partners.

Male circumcision and HIV infection in four cities in sub-Saharan Africa.

OBJECTIVES: To explore the role of male circumcision in the spread of HIV infection in four urban populations in sub-Saharan Africa. DESIGN AND METHODS: A cross-sectional population based study was conducted in four cities in sub-Saharan Africa with different levels of HIV infection. HIV prevalence among adults was relatively low in Cotonou (Benin) and in Yaoundé (Cameroon), and exceeded 25% in Kisumu (Kenya) and in Ndola (Zambia). In each city, a random sample was taken of men and women aged 15-49 years from the general population. Consenting study participants were interviewed about their sociodemographic characteristics and their sexual behaviour, and were tested for HIV, herpes simplex virus type 2, syphilis, gonorrhoea and chlamydial infection. Men underwent a genital examination. RESULTS: In Cotonou and in Yaoundé, the two low HIV prevalence cities, 99% of men were circumcised. In Kisumu 27.5% of men were circumcised, and in Ndola this proportion was 9%. In Kisumu, the prevalence of HIV infection was 9.9% among circumcised men and 26.6% among uncircumcised men. After controlling for socio-demographic characteristics, sexual behaviour and other sexually transmitted infections, the protective effect of male circumcision remained with an adjusted odds ratio of 0.26 (95% confidence interval = 0.12-0.56). In Ndola, the prevalence of HIV infection was 25.0% in circumcised men and 26.0% in uncircumcised men. The power was insufficient to adjust for any differences in sexual behaviour. CONCLUSIONS: The differences in epidemic spread of HIV are likely to be due to differences in the probability of transmission of HIV during sexual exposure as well as differences in sexual behaviour. Male circumcision is one of the factors influencing the transmission of HIV during sexual intercourse, and this study confirms the population level association between HIV and lack of male circumcision, as well as a strong individual level association in Kisumu, the only city with sufficient power to analyze this association.

Comparison of key parameters of sexual behaviour in four African urban populations with different levels of HIV infection.

OBJECTIVE: To explore whether differences in sexual behaviour could explain differences in the rate of spread of HIV in four urban populations in Africa. METHODS: A cross-sectional, population-based study was conducted in two cities where the prevalence of HIV among adults exceeded 20% (Kisumu, Kenya and Ndola, Zambia) and two cities with a much lower HIV prevalence among adults (Cotonou, Benin and Yaoundé, Cameroon). In each of these cities, approximately 1000 men and 1000 women, aged 15-49 years, were randomly selected from the general population. Consenting men and women were interviewed about their sociodemographic characteristics and sexual behaviour, including characteristics of spouses and of non-spousal partners. Key parameters of sexual behaviour were compared between the four cities. RESULTS: On average, women in the high HIV prevalence cities had their sexual debut earlier than in the other cities. Men and women in Kisumu and Ndola got married earlier than men and women in Cotonou and Yaoundé. High rates of partner change, contacts with sex workers, concurrent partnerships and large age differences between partners were no more common in the two high HIV prevalence cities than in the two low HIV prevalence cities. CONCLUSIONS: In these four African populations, differences in reported sexual behaviour could not explain the differences in rate of spread of HIV. In all four cities, high-risk sexual behaviour patterns were identified.

Why do young women have a much higher prevalence of HIV than young men? A study in Kisumu, Kenya and Ndola, Zambia.

OBJECTIVE: To examine the factors responsible for the disparity in HIV prevalence between young men and women in two urban populations in Africa with high HIV prevalence. DESIGN: Cross-sectional survey, aiming to include 1000 men and 1000 women aged 15-49 years in Kisumu, Kenya and Ndola, Zambia. METHODS: Participants were interviewed and tested for HIV and other sexually transmitted infections. Analyses compared the marital and non-marital partnership patterns in young men and women, and estimated the likelihood of having an HIV-infected partner. RESULTS: Overall, 26% of individuals in Kisumu and 28% in Ndola were HIV-positive. In both sites, HIV prevalence in women was six times that in men among sexually active 1 5-19 year olds, three times that in men among 20-24 year olds, and equal to that in men among 25-49 year olds. Age at sexual debut was similar in men and women, and men had more partners than women. Women married younger than men and marriage was a risk factor for HIV, but the disparity in HIV prevalence was present in both married and unmarried individuals. Women often had older partners, and men rarely had partners much older than themselves. Nevertheless, the estimated prevalence of HIV in the partners of unmarried men aged under 20 was as high as that for unmarried women. HIV prevalence was very high even among women reporting one lifetime partner and few episodes of sexual intercourse. CONCLUSIONS: Behavioural factors could not fully explain the discrepancy in HIV prevalence between men and women. Despite the tendency for women to have older partners, young men were at least as likely to encounter an HIV-infected partner as young women. It is likely that the greater susceptibility of women to HIV infection is an important factor both in explaining the male-female discrepancy in HIV prevalence and in driving the epidemic. Herpes simplex virus type 2 infection, which is more prevalent in young women than in young men, is probably one of the factors that increases women's susceptibility to HIV infection.

Condom use and its association with HIV/sexually transmitted diseases in four urban communities of sub-Saharan Africa.

OBJECTIVES: To estimate rates of condom use in four urban populations in sub-Saharan Africa and to assess their association with levels of HIV infection and other sexually transmitted diseases (STDs). METHODS: Data were obtained from a multicentre study of factors that determine the differences in rate of spread of HIV in four African cities. Consenting participants were interviewed on sexual behaviour, and also provided blood and urine samples for testing for HIV infection and other STDs. Data on sexual behaviour included information on condom use during all reported spousal and non-spousal partnerships in the past 12 months. RESULTS: A total of 2116 adults aged 15-49 years were interviewed in Cotonou (Benin), 2089 in Yaoundé (Cameroon), 1889 in Kisumu (Kenya) and 1730 in Ndola (Zambia). Prevalence rates of HIV infection were 3.4% in Cotonou, 5.9% in Yaoundé, 25.9% in Kisumu and 28.4% in Ndola. Reported condom use was low, with the proportions of men and women who reported frequent condom use with all non-spousal partners being 21-25%, for men and 11-24% for women. A higher level of condom use by city was not associated with lower aggregate level of HIV infection. The proportions of men reporting genital pain or discharge during the past 12 months were significantly lower among those reporting frequent condom use in all sites except Yaoundé: in Cotonou, adjusted odds ratio (OR) = 0.28, 95% confidence interval (CI) = 0.09-0.94; in Kisumu, adjusted OR = 0.34, 95% CI = 0.14-0.83; and in Ndola, adjusted OR = 0.33, 95% CI = 0.12-0.90. The same association was found for reported genital ulcers in two sites only: in Cotonou, adjusted OR = 0.14, 95% CI = 0.02-1.02; and in Kisumu, adjusted OR = 0.18, 95% CI = 0.04-0.75. There were few statistically significant associations between condom use and biological indicators of HIV infection or other STDs in any of the cities. CONCLUSION: Similar levels of condom use were found in all four populations, and aggregate levels of condom use by city could not discriminate between cities with high and low level of HIV infection. It seems that rates of condom use may not have been high enough to have a strong impact on HIV/STD levels in the four cities. At an individual level, only a male history of reported STD symptoms was found to be consistently associated with lower rates of reported condom use.

Educational level is associated with condom use within non-spousal partnerships in four cities of sub-Saharan Africa.

BACKGROUND: Rates of condom use in sub-Saharan Africa have remained too low to curb HIV/sexually transmitted disease (STD) epidemics. A better understanding of the main determinants of condom use would aid promotion. METHODS: Cross-sectional population surveys were conducted in four cities in sub-Saharan Africa: Yaoundé, Cameroon; Cotonou, Benin; Ndola, Zambia; and Kisumu, Kenya. In each city, the aim was to interview a random sample of 1000 men and 1000 women aged 15--49 years, including questions on characteristics of non-spousal partnerships in the past 12 months. RESULTS: Data on condom use were available for 4624 non-spousal partnerships. In the four cities, the proportion of partnerships in which condoms were used always or most of the time ranged from 23.8 to 33.5% when reported by men and from 10.7 to 25.9% when reported by women. Based on the reports from men, condom use was associated with higher educational level of the male partner in Yaoundé [adjusted odds ratio (aOR) = 1.76] and Ndola (aOR = 2.94) and with higher educational level of the female partner in Cotonou (aOR = 2.36) and Kisumu (aOR = 2.76). Based on the reports from women, condom use was associated with higher educational level of the female partner in Kisumu (aOR = 2.60) and Ndola (aOR = 4.50) and with higher educational level of the male partner in Yaoundé (aOR = 3.32). Associations with other determinants varied across cities and for men and women. CONCLUSIONS: Education was found to be a key determinant of condom use in all four cities. This suggests that educational level increases response to condom promotion and highlights the need for special efforts to reach men and women with low educational attainment.

Concurrent sexual partnerships and HIV prevalence in five urban communities of sub-Saharan Africa.

OBJECTIVE: To estimate parameters of concurrent sexual partnerships in five urban populations in sub-Saharan Africa and to assess their association with levels of HIV infection and other sexually transmitted infections (STI). METHODS: Data were obtained from a multicentre study of factors which determine the differences in rate of spread of HIV in five African cities. Consenting participants were interviewed on sexual behaviour and at four of the five sites also provided a blood and a urine sample for testing for HIV and other STI. Data on sexual behaviour included the number of partnerships in the 12 months preceding the interview as well as the dates of the start and end of each partnership. Summary indices of concurrent sexual partnerships -- some of which were taken from the literature, while others were newly developed -- were computed for each city and compared to HIV and STI prevalence rates. RESULTS: A total of 1819 adults aged 15--49 years were interviewed in Dakar (Senegal), 2116 in Cotonou (Benin), 2089 in Yaoundé (Cameroon), 1889 in Kisumu (Kenya) and 1730 in Ndola (Zambia). Prevalence rates of HIV infection were 3.4% for Cotonou, 5.9% for Yaoundé, 25.9% for Kisumu and 28.4% for Ndola, and around 1% for Dakar. The estimated fraction of sexual partnerships that were concurrent at the time of interview (index k) was relatively high in Yaoundé (0.98), intermediate in Kisumu (0.44) and Cotonou (0.33) and low in Ndola (0.26) and in Dakar (0.18). An individual indicator of concurrency (iic) was developed which depends neither on the number of partners nor on the length of the partnerships and estimates the individual propensity to keep (positive values) or to dissolve (negative values) on-going partnership before engaging in another one. This measure iic did not discriminate between cities with high HIV infection levels and cities with low HIV infection levels. In addition, iic did not differ significantly between HIV-infected and uninfected people in the four cities where data on HIV status were collected. CONCLUSION: We could not find evidence that concurrent sexual partnerships were a major determinant of the rate of spread of HIV in five cities in sub-Saharan Africa. HIV epidemics are the result of many factors, behavioural as well as biological, of which concurrent sexual partnerships are only one.

HIV infection among youth in a South African mining town is associated with herpes simplex virus-2 seropositivity and sexual behaviour.

OBJECTIVES: To determine the seroprevalence of HIV and herpes simplex virus-2 (HSV-2) by age and gender among young people aged 14--24 years in a South African town and to identify risk factors for HIV infection. DESIGN: A community-based, cross-sectional study was conducted on a random sample of men (n = 723) and women (n = 784) living in a township in the Carletonville district of South Africa. METHODS: Potential demographic and behavioural risk factors associated with HIV were recorded by questionnaire and biological tests were performed on serum and urine. Data analysis was performed using multivariate logistic regression. RESULTS: Among men and women the prevalence of HIV infection was 9.4 and 34.4%, respectively, and of positive HSV-2 serology was 17.0 and 53.3%, respectively. Among 24-year-old women the prevalence of HIV was 66.7% [95% confidence interval (CI), 54.6--77.3%]. HSV-2 seropositivity was a strong independent risk factor for HIV infection with odds ratios of 5.3 (95% CI, 2.7--10.3) for men and 8.4 (95% CI, 4.9--14.2) for women. There was no independent effect of age at first sex or serological markers of other sexually transmitted infections on HIV infection. CONCLUSIONS: HIV infection among young women increases rapidly after the onset of sexual activity and reaches extremely high levels by 24 years of age. These findings suggest that rates of HIV transmission from men to women are high and that HSV-2 plays a major role in the spread of HIV in this population.

Ecological and individual level analysis of risk factors for HIV infection in four urban populations in sub-Saharan Africa with different levels of HIV infection.

OBJECTIVE: To identify factors that could explain differences in rate of spread of HIV between different regions in sub-Saharan Africa. DESIGN: Cross-sectional study. METHODS: The study took place in two cities with a relatively low HIV prevalence (Cotonou, Benin and Yaoundé, Cameroon), and two cities with a high HIV prevalence (Kisumu, Kenya and Ndola, Zambia). In each of these cities, a representative sample was taken of about 1000 men and 1000 women aged 15-49 years. Consenting men and women were interviewed about their socio-demographic background and sexual behaviour; and were tested for HIV, herpes simplex virus type 2 (HSV-2), syphilis, Chlamydia trachomatis and Neisseria gonorrhoea infection, and (women only) Trichomonas vaginalis. Analysis of risk factors for HIV infection was carried out for each city and each sex separately. Adjusted odds ratios (aOR) were obtained by multivariate logistic regression. RESULTS: The prevalence of HIV infection in sexually active men was 3.9% in Cotonou, 4.4% in Yaoundé, 21.1% in Kisumu, and 25.4% in Ndola. For women, the corresponding figures were 4.0, 8.4, 31.6 and 35.1%. High-risk sexual behaviour was not more common in the high HIV prevalence cities than in the low HIV prevalence cities, but HSV-2 infection and lack of circumcision were consistently more prevalent in the high HIV prevalence cities than in the low HIV prevalence cities. In multivariate analysis, the association between HIV infection and sexual behavioural factors was variable across the four cities. Syphilis was associated with HIV infection in Ndola in men [aOR = 2.7, 95% confidence interval (CI) = 1.5-4.91 and in women (aOR = 1.7, 95% CI = 1.1-2.6). HSV-2 infection was strongly associated with HIV infection in all four cities and in both sexes (aOR ranging between 4.4 and 8.0). Circumcision had a strong protective effect against the acquisition of HIV by men in Kisumu (aOR = 0.25, 95% CI = 0.12-0.52). In Ndola, no association was found between circumcision and HIV infection but sample sizes were too small to fully adjust for confounding. CONCLUSION: The strong association between HIV and HSV-2 and male circumcision, and the distribution of the risk factors, led us to conclude that differences in efficiency of HIV transmission as mediated by biological factors outweigh differences in sexual behaviour in explaining the variation in rate of spread of HIV between the four cities.

Multicentre study on factors determining differences in rate of spread of HIV in sub-Saharan Africa: methods and prevalence of HIV infection.

OBJECTIVE: The objective of this study was to explore whether the differences in rate of spread of HIV in different regions in sub-Saharan Africa could be explained by differences in sexual behaviour and/or factors influencing the probability of HIV transmission during sexual intercourse. METHODS: A cross-sectional, population-based study was conducted in two cities with a high HIV prevalence (Kisumu in Kenya and Ndola in Zambia) and two cities with a relatively low HIV prevalence (Cotonou in Benin and Yaoundé in Cameroon). In each of these cities, approximately 1000 men and 1000 women, aged 15-49 years, were randomly selected from the general population. Consenting men and women were interviewed and were tested for HIV, syphilis, herpes simplex virus type 2 (HSV-2), gonorrhoea, chlamydial infection and trichomoniasis (the latter for women only). In addition, a survey was conducted on a random sample of 300 sex workers in each city. The research instruments, including the questionnaires and the laboratory procedures, were standardized to permit comparison of results. RESULTS: The numbers of men interviewed were 1021 in Cotonou, 973 in Yaoundé, 829 in Kisumu, and 720 in Ndola. The corresponding figures for women were 1095, 1116, 1060 and 1130. In Yaoundé, Kisumu and Ndola, the response rates for men were lower than for women due to failure to make contact with eligible men. The proportion of eligible women who were interviewed was 86% in Yaoundé, and 89% in Kisumu and Ndola. In Yaoundé, 76% of eligible men were interviewed, along with 82% in Kisumu and 75% in Ndola. The prevalence of HIV infection in men was 3.3% in Cotonou, 4.1% in Yaoundé, 19.8% in Kisumu and 23.2% in Ndola. For women, the respective figures were 3.4, 7.8, 30.1 and 31.9%. The prevalence of HIV infection among women aged 15-19 years was 23.0% in Kisumu and 15.4% in Ndola. Among women in Kisumu who had their sexual debut 5 years before the interview, the prevalence of HIV infection was 46%; in Ndola, it was 59%. Among sex workers, the prevalence of HIV infection was 57.5% in Cotonou, 34.4% in Yaoundé, 74.7% in Kisumu and 68.7% in Ndola. CONCLUSIONS: The HIV prevalence rates in the general population confirmed our preliminary assessment of the level of HIV infection in the four cities, which was based on estimates of HIV prevalence from sentinel surveillance among pregnant women. The very high prevalence of HIV infection among young women in Kisumu and Ndola calls for urgent intervention.

Proportion of HIV infections attributable to other sexually transmitted diseases in a rural Ugandan population: simulation model estimates.

BACKGROUND: Unprotected heterosexual contact in the presence of other sexually transmitted diseases (STD) enhances the probability of HIV transmission. The objective of this study was to estimate the proportion of HIV infections attributable to STD in rural Uganda. METHODS: Simulation modelling scenarios of the transmission dynamics of HIV infection and of ulcerative and non-ulcerative STD were employed to address this objective, drawing on data from a specific rural population cohort of 10,000 in south-west Uganda. RESULTS: In simulations of the initial 10-year period of the HIV epidemic (1980-1990), over 90% of HIV infections were attributed to STD. Even given conservative assumptions about the prevalence of STD and about their enhancing effects on HIV transmission, STD played a critical role in the rapid and extensive spread of HIV infection. The role of STD decreased with progression of the HIV epidemic. CONCLUSIONS: In developing countries, control of the spread of HIV infection may benefit substantially from successful STD intervention programmes, and particularly in areas where HIV infection is not already well established.

PIP: Unprotected heterosexual contact in the presence of other sexually transmitted diseases (STDs) increases the likelihood of HIV transmission. A detailed simulation model of HIV transmission dynamics and of ulcerative and nonulcerative STDs was fit to a rural population in southwest Uganda in an attempt to estimate the proportion of HIV infections attributable to STDs in the area. The study population includes the total population of approximately 10,000 in a cluster of 15 villages in Masaka district where population surveys have been conducted annually since mid-1990. In simulations of the initial 10-year period of the HIV epidemic of 1980-90, more than 90% of HIV infections were attributed to STDs. Even making conservative assumptions about the prevalence of STDs and their enhancing effects upon HIV transmission, STDs played an important role in the rapid and extensive spread of HIV infection. The role of STDs decreased with the progression of the HIV epidemic.

Dynamics of HIV infection and AIDS in central African cities.

A detailed stochastic model of HIV infection and AIDS for large cities in central Africa is described, which reproduces past events in Kinshasa, Zaire and projects rapid future spread of the disease, consistent with recent findings for Nairobi, Kenya. Most of the parameters used describe the behaviour of individuals, and it is therefore possible to look at the effects of changes in such behaviour, and thus to test various strategies aimed at providing effective public health policies. The model demonstrates that, if the spread of infection is to be controlled, changes in the behaviour of the major risk groups are essential. With appropriate modifications, this model could be adapted for use elsewhere in Africa.

Estimation of direct cost and resource allocation in intensive care: correlation with Omega system.

OBJECTIVE: An instrument able to estimate the direct costs of stays in Intensive Care Units (ICUs) simply would be very useful for resource allocation inside a hospital, through a global budget system. The aim of this study was to propose such a tool. DESIGN: Since 1991, a region-wide common data base has collected standard data of intensive care such as the Omega Score, Simplified Acute Physiologic Score, length of stay, length of ventilation, main diagnosis and procedures. The Omega Score, developed in France in 1986 and proved to be related to the workload, was recorded on each patient of the study. SETTING: Eighteen ICUs of Assistance Publique-Hôpitaux de Paris (AP-HP) and suburbs. PATIENTS: 1) Hundred twenty-one randomly selected ICU patients; 2) 12,000 consecutive ICU stays collected in the common data base in 1993. MEASUREMENTS: 1) On the sample of 121 patients, medical expenditure and nursing time associated with interventions were measured through a prospective study. The correlation between Omega points and direct costs was calculated, and regression equations were applied to the 12,000 stays of the data base, leading to estimated costs. 2) From the analytic accounting of AP-HP, the mean direct cost per stay and per unit was calculated, and compared with the mean associated Omega score from the data base. In both methods a comparison of actual and estimated costs was made. RESULTS: The Omega Score is strongly correlated to total direct costs, medical direct costs and nursing requirements. This correlation is observed both in the random sample of 121 stays and on the data base' stays. The discrepancy of estimated costs through Omega Score and actual costs may result from drugs, blood product underestimation and therapeutic procedures not involved in the Omega Score. CONCLUSIONS: The Omega system appears to be a simple and relevant indicator with which to estimate the direct costs of each stay, and then to organise nursing requirements and resource allocation.

Type of partnership and heterosexual spread of HIV infection in rural Uganda: results from simulation modelling.

The objective was to estimate the likely percentage of HIV infections that may be attributable to one-off partnerships (such as those between female sex workers and their clients) and longer-term partnerships in rural Uganda. This was addressed by the application of a microsimulation model (SimulAIDS) of the transmission dynamics of HIV infection, drawing on data from a population cohort of 10,000 in rural Uganda. For a scenario reproducing documented characteristics of the study population in 1990, when adult HIV prevalence was 9%, and during subsequent follow up (1990-1994), when adult HIV incidence was 8 per 1000 person-years, the percentage of HIV infections in men (women) attributed to one-off partnerships decreased from 96% (26%) during 1980 to 67% (8%) in 1989 and 22% (5%) in 1994. Reducing HIV transmission between one-off partners early in an HIV epidemic may substantially limit the potential for the spread of HIV infection. At a later phase, prevention must also focus on control of transmission between longer-term HIV-discordant partners.

PIP: This paper presents results of a study using a simulation model in estimating the likely percentage of HIV infections that may be attributable to one-off partnerships (e.g., female sex workers and their clients) and longer-term partnerships among the rural population of Uganda. The study adopted SimulAIDS, an age-structured microsimulation model of the HIV infection dynamics along with ulcerative and non-ulcerative sexually transmitted diseases. Data obtained from the 10,000 cohort population reflected a decline in the incidence of HIV in adults between 1990 and 1994, a result which could be attributed to one-off sexual partnerships in 1980, 1984, 1989, 1994, and 1999. The study supports that minimizing transmission of HIV from short-term sexual partnerships during early stage of the disease could have a strong impact on the reduction in the spread of HIV infection.

Past occupational exposure to asbestos among men in France.

OBJECTIVES: This study aimed at reconstructing changes in the frequency and levels of occupational asbestos exposure in France over the past century. METHODS: Work histories were collected during 11 population-based case-referent studies recently carried out in France, and an asbestos-specific job-exposure matrix including 10 625 jobs was used to estimate indices of past occupational asbestos exposure. The results were estimated from a sample of 4287 subjects, bootstrapped 200 times. RESULTS: The distribution of socioeconomic categories within the sample was compared with that of the general population in 1954, 1962, 1968, 1975, and 1982. The proportion of blue-collar workers was similar. The highest proportion of exposed subjects was found between 1950 and 1980. Around 10% of each 10-year age class was exposed to asbestos. For those born in 1930-1939, 15.2% was exposed between the ages of 20 and 29 years. For each age class born in 190-1939, the proportion exposed at least once by 60 years of age ranged from 18.2% to 24.5 % and, of those exposed, the cumulative duration of exposure ranged from 11.3 to 15.4 years by the age of 60 years. A population exposure index showed that the heaviest exposure occurred between 1960 and 1970 and that the age classes born between 1920 and 1929 were the most heavily exposed. Time trends showed that the mean value of this index for the men aged 20-59 years reached a peak in the 1960s and then decreased. CONCLUSIONS: This study presents data of reasonable validity about occupational asbestos exposure in France and its trends over the past century; the data are being used to forecast the development of male mortality from mesothelioma in France.

An intelligent computer-assisted instruction system designed for rural health workers in developing countries.

This paper describes an intelligent computer-assisted instruction system that was designed for rural health workers in developing countries. This system, called Consult-EAO, includes an expert module and a coaching module. The expert module, which is derived from the knowledge-based decision support system Tropicaid, covers most of medical practice in developing countries. It allows for the creation of outpatient simulations without the help of a teacher. The student may practice his knowledge by solving problems with these simulations. The system gives some initial facts and controls the simulation during the session by guiding the student toward the most efficient decisions. All student answers are analyzed and, if necessary, criticized. The messages are adapted to the situation due to the pedagogical rules of the coaching module. This system runs on PC-compatible computer.

[Organization and quality control of a clinical database on intensive care medicine in central and suburban Paris]. / Mise en oeuvre et évaluation d'une base de données commune aux services de réanimation d'Ile-de-France.

BACKGROUND: Epidemiology and medical care appraisal of intensive care medicine relies on the homogeneity of information systems. This work is about a collaborative database related to intensive care units in Paris and its suburb. METHODS: A college of intensivists defined a standard dataset about stays, outcomes, severity of illness, diagnoses and work load, which are collected and analysed by a data management center. A quality control of the database was performed on a random sample of 199 stays. RESULTS: In 1996, 25 intensive care units participated in the database which encompassed more than 35,000 stays. The control of data quality showed a good reliability of data about stays, severity and workload but reproducibility of diagnosis coding has to be improved by means of more accurate coding guidelines. CONCLUSION: This database of case-mix and outcome information allows comparison and medical care appraisal of intensive care units.