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.

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.

[Evaluation of amoxicillin-clavulanic acid prescriptions in a teaching hospital of Parisian suburb]

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.

Potential for an intervention based on male circumcision in a South African town with high levels of HIV infection

The study aims to investigate the potential for an intervention based on male circumcision in a South African town with a high level of HIV infection. It draws on two cross-sectional studies conducted in August 2000 among a sample of 606 male adults aged 13-59 years, and in August 1999 among a sample of 723 male youth aged 14-24 years. A qualitative study was further conducted on perceptions and attitudes towards male circumcision using focus group discussions and in-depth interview. Among men aged 25-59 years, 36% reported being circumcised The median reported age at circumcision was 20. A total of 42% of 14-24-year-old circumcised men reported having been circumcised in a medical setting. Circumcised and uncircumcised men did not differ in their sexual behaviour or in sociodemographic characteristics, apart from their age and ethnic group. Among 467 uncircumcised adult men, 59% said that they would be circumcised if circumcision reduced the chances of getting HIV and STDs. Focus group discussions showed that circumcision is still important to many people, and is seen as an essential part of the transition into adulthood Reluctance to be circumcised was mainly related to the possibility of adverse outcomes of circumcision performed in non-medical settings, although initiation schools remain attractive for education and transmission of cultural values. Some misconceptions remain, however, especially about the preventative nature of circumcision for STD transmission. The cultural importance of male circumcision has weakened over the last century and when it is done it is often by a medical practitioner. An intervention that would include male circumcision seems feasible in communities such as the one where this study was conducted but needs to be carefully planned in order to ensure that participants understand that circumcision probably reduces, but certainly does not eliminate, the risk of HIV infection.

Implementation of a system of surveillance of childhood injuries involved in a Safe Community program: the example of Boulogne-Billancourt (France)

OBJECTIVES

To provide precise information about child injuries, intended to promote preventive actions, in keeping with the general pattern of a Safe Community program implemented in Boulogne-Billancourt (France) since 1997.

METHODS

Information about children under 16 injured in the city of Boulogne-Billancourt and its surroundings, are extracted in a database.

DISCUSSION

The Boulogne-Billancourt database is the first permanent and specific childhood injury surveillance system in France integrated in a "Safe Community". It may constitute an "alarm system" by allowing rapid implementation of preventive action. The final evaluation of the collected data will be performed at the end of the program (after five years).

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.

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.

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.

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.

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.

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.

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.

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.

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.

[Frequency of childhood injuries: first results of the Boulogne-Billancourt registry]

BACKGROUND

Boulogne-Billancourt database is in France the only permanent and specific childhood injury surveillance system. Integrated in an safe community program designed by the World Health Organization (WHO), the aims of a local database are to provide precise information intended to implement prevention actions.

METHOD

All children less than sixteen years old living in Boulogne-Billancourt, victims of injuries occurring in that town, and requiring hospital care, are targeted.

RESULTS

Two thousand five hundred and eighty accidents have been computed between 1(st) January 1998 and 31 December 1999, i.e. an average annual incidence of 79.7/1000 children. As in other similar databases, domestic accidents are prevalent in the average (40%), even though after five years old school injuries become the most frequent ones (36%). Falls are the main mechanism involved in injury at any age (44 to 54%). Distribution of other mechanisms varies with respect to age: foreign body prevalence is maximum between one and four (2.5%), struck-collisions (38%) between ten and fifteen years old. A significant increase of falls involving roller-skates or skateboards has been observed between 1998 and 1999 (3.8% versus 1.1%, p<0.001). Predominanting injury causes are contusions (38%), mainly head trauma (10%), open wounds (16%), fractures (10%), and sprains (6%). Two hundred and twenty four injuried children have been admitted in 1998, 205 in 1999, i.e. respectively 13.8/1000 and 12.7/1000 children dwelling in Boulogne. Overall recurrence rate is 32%, reaching 47% after eleven years old. A significant relationship has been observed between injury recurrence and problems related to education (odds ratio: 2.95; 95% CI: 1.75-5.00), atypical parenting situation (odds ratio: 1.70; 95% CI: 1.20-2.30), and family discord (odds ratio: 1.62; 95% CI: 1.05-2.50). Household accidents are the most avoidable ones in parents'opinion. This is not the case for road-traffic accidents, given evidence of the lack of means of protection observed in bicycle injuries.

CONCLUSION

In spite of methodological issues such as control of exhaustivity of data, or difficulties to maintain a long-term surveillance sytem, this project worth carrying on with regard to provided information and usefulness for prevention. Other similar community experiences should be implemented with the aim of setting up a national-wide surveillance system, based on an homogenous data collection.

Is the Kasai operation still indicated in children older than 3 months diagnosed with biliary atresia?

OBJECTIVES

The prognosis of hepatoportoenterostomy (the Kasai operation) for biliary atresia worsens when the age at surgery increases. This study examines whether the Kasai operation remains justified after 3 months of life.

STUDY DESIGN

Records for all patients with biliary atresia living in France and born in the years 1986 to 1996 were reviewed, and patients were classified into 3 groups: group 1 (n = 30), no contraindication to the Kasai operation, but orientation to de novo transplantation; group 2 (n = 380), age at Kasai operation <90 days; and group 3 (n = 60), age at Kasai operation > or =90 days. Survival with native liver, survival after liver transplantation, and overall survival (Kaplan-Meier method) were compared by using the log-rank test.

RESULTS

Five-year (10-year) survival with native liver was 35% (30%) in group 2 and 25% (22%) in group 3 (P =.03). Five-year overall survival was 57%, 74%, and 55% in groups 1, 2, and 3, respectively (P =.003). Poor results in groups 1 and 3 were mainly due to increased pre-transplantation mortality, but survival after transplantation was not significantly different in the 3 groups.

CONCLUSIONS

Performance of the Kasai operation after 3 months of age is justified in selected cases, because it may obviate liver transplantation. Preoperative evaluation should exclude patients with advanced liver disease for whom liver transplantation should not be delayed.

Future trends in mortality of French men from mesothelioma

OBJECTIVES

Previous projections of mortality from mesothelioma among French men have used the age-generation method, based on the Poisson regression model. In this study an alternative method to model mortality from mesothelioma was used to predict its future trend: this method was based on the risk function that links this mortality to past exposure to asbestos, combined with population exposure data.

METHOD

Data on past French asbestos imports were used to model the overall past exposure to asbestos in men and assess two extreme scenarios (optimistic and pessimistic) for its future trends. The number of male deaths occurring between the ages of 50 and 79, from 1997-2050, was then calculated with the risk function for mesothelioma.

RESULTS

The results showed that mortality from mesothelioma among French men aged 50-79 will continue to increase, reaching a peak averaging between 1140 (optimistic scenario) and 1300 deaths (pessimistic scenario) annually around the years 2030 and 2040, respectively. No preventive measures applied now will affect this trend before then. These results are similar to those of two other predictions of mortality from mesothelioma among French men: a peak around 2030 of 800-1600 deaths annually among men aged 25-89 years, and a peak around 2020 of 1550 deaths annually among men aged 40-84.

CONCLUSIONS

Our results indicate that between 1997 and 2050, the most optimistic and pessimistic trends of future exposure will lead to the deaths from mesothelioma of between 44 480 and 57 020 men, with a corresponding loss of from 877 200 to 1 171 500 person-years of life.

Computer modeling of population exposure to a carcinogen: the example of asbestos and mesothelioma mortality in France

The multistage theory of carcinogenesis allows models to be constructed that provide the individual probability of a diagnosed tumor at a given age as a function of the person's past exposure to carcinogenic agents (exposure level versus age), the time since exposure, and age. When exposure to a carcinogenic agent and its impact in terms of morbidity and mortality are modeled on the scale of the general population, individual exposures must often be estimated. If appropriate data do not already exist, this difficult task necessitates expensive and difficult investigations. We propose here a method that allows this global exposure to be modeled without needing to know the individual exposures. The method is used and illustrated in the context of modeling the asbestos exposure of the French male population and calculating its mortality rate from mesothelioma (a type of cancer for which asbestos is the only carcinogen and for which a risk function based on the multistage theory of carcinogenesis exists). This method assumes that the exposure functions (how exposure levels vary with age) for all individuals are the same, with the exception of one parameter. That is, it utilizes a hypothesis that we called the hypothesis of the Standard Exposure Window (SEW). We used two methods to calculate the probability of death from mesothelioma in a representative sample of the French male population for whom individual histories of asbestos exposure are known: we applied the risk function to all the individuals, and we applied the SEW hypothesis. The number of deaths obtained by the two methods are very close and fit the observed mortality data satisfactorily.

Sexual behavior, heterosexual transmission, and the spread of HIV in sub-Saharan Africa: a simulation study

A stochastic simulation model has been used to assess the extent to which variation in sexual behavior and transmission characteristics can explain the striking spatial heterogeneity in the prevalence of HIV among different geographical locations in sub-Saharan Africa. Of the various parameters describing sexual behavior the most important determinant of the spread of HIV is the proportion of men engaging in sexual relationships with people other than spouses, including contacts with sex workers and short-term partners. Considering factors other than sexual behavior the model shows that this heterogeneity in HIV prevalence could be the result of differences in the transmission probability of HIV or in the prevalence of other sexuality transmitted diseases. These factors could play a key role in determining the patterns of spread of HIV in sub-Saharan Africa and should be considered in the design of intervention strategies.

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.

Epidemiology of biliary atresia in France: a national study 1986-96

BACKGROUND/AIMS

The reported incidence of biliary atresia varies from 5 to 32/100000 live births. The existence of seasonality and/or clustering is controversial. Based on a large population analysis, we examined the incidence of biliary atresia in France, and the space-time distribution of cases.

METHODS

All patients with biliary atresia living in France and born in the years 1986-96 were recorded. Geographic distribution, seasonality, time clustering and space-time clustering were analysed. Statistical analysis used the Chi square test, the Spearman nonparametric correlation test, the Walter and Elwood test for seasonality of events and Knox analysis for time and space-time clustering.

RESULTS

We identified 461 patients: 421 born in metropolitan France (incidence 5.12 [4.63-5.61]/100000 live births), and 40 born in overseas territories. No significant regional variation in incidence was found in metropolitan France, while the incidence was higher in French Polynesia (incidence 29.4 [15.4-43.3]/100000 live births) (p<0.001). Seasonality, time-clustering and time-space clustering could not be demonstrated.

CONCLUSIONS

1) The incidence of BA was 5.7-fold higher in Polynesia than in metropolitan France. 2) Neither seasonal variation in incidence nor clustering was identified.

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.

Prognosis of biliary atresia in the era of liver transplantation: French national study from 1986 to 1996

Since the sequential treatment of Kasai operation with or without liver transplantation became available, the overall prognosis of biliary atresia remains unclear. This study examined the prognostic factors from diagnosis. All patients with biliary atresia living in France and born in the years 1986 to 1996 were reviewed. Actuarial survival rates were calculated for survival with native liver, survival after liver transplantation, and overall survival. Potential prognostic factors were analyzed using the logrank test and the Cox model. A total of 472 patients were identified. Ten-year overall survival was 68%. Independent prognostic factors for overall survival were (S = 10-year rates) performance of Kasai operation (performed: S = 69%; not performed: S = 50%), age at Kasai operation (</=45 days: S = 80%; >45 days: S = 66%), anatomical pattern of extrahepatic bile ducts, polysplenia syndrome, experience of the center (</=2 new biliary atresia [BA] patients/year [24 centers]: S = 54%; 3 to 5 [2 centers]: S = 60%; >/=20 [1 center]: S = 78%). Survival with native liver depended on the same independent prognostic factors. In conclusion (1) Kasai operation remains the first line treatment of BA, and (2) early performance of Kasai operation and treatment in an experienced center reduces the need for liver transplantation in infancy and childhood and provides children with the best chance of survival.

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.

[Organization and quality control of a clinical database on intensive care medicine in central and suburban Paris]

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.

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.

[Cornea procurement and grafts and number of patients on waiting lists. Data collection in France between 1990 and 1994]

OBJECTIVES

Analyze annual corneal graft procurement and transplantation in France.

METHODS

Data collected from all public and private health centers in France in a survey conducted in August 1994 by the general health directory were analyzed by the French Graft authorities.

RESULTS

Between 1990 and the first semester 1994, an annual mean of 3205 corneal grafts were performed in France. The annual number of grafts fell by 27% between 1991 and 1992 then stabilized at 2700 grafts per year. Eighty percent of the grafts were performed in public institutions. Less than 4% of the patients were foreigners. The number of patients on waiting lists on June 30, 1994 was 7129, i.e. 2.7 times the number of transplantations in 1993. Mean annual cornea procurement between 1991 and the first semester 1994 was 2930. Corneas were removed at the morgue in 78% of the cases or in the operating room in 19% (multiple organ procurement) and 1.5% (cornea alone). Grafted corneas came from public hospitals in 72% of the cases. Fifty-seven percent of the grafts used in private institutions were imported. The mean annual number of imported corneas can be estimated at 280. This number has increased by 127% since 1990 and corresponds to 8% of the grafted corneas.

CONCLUSION

The number of corneal grafts in France is similar to that in other European countries, but the number of patients on waiting lists is high and French eye banks had a restricted role.

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.

Graduate Programs in Medical Informatics at the Patis Universities

Most medical schools in France have chairs in Biostatistics and Medical Informatics to coordinate the teaching of these two disciplines both within the regular curriculum of the medical studies and as a specialized teaching. This paper describes the current medical informatics specialized program offered at the Paris Universities. Since 1968 the program has comprised a Master of Science and a Ph.D. degree. At the Master Level, despite several reforms and in-depth program revisions, the curriculum is still organized as a set of modules of 100 hours teaching with a large freedom for the medical faculties to define the contents of the courses and for the students to organize their studies and combine medical informatics, biomathematics and biostatistics training. Since 1990, an intensive one-year full-time course is offered, called Advanced Study Diploma in Medical Informatics, which is strongly research oriented. This program seems a good strategy to form medical informatics specialists who have initially received a broader education in informatics and statistics.

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.

Statistical analysis of histomorphological findings in medullary thyroid carcinoma: distinction between the different familial forms of the disease. G.E.T.C. Groupe d'Etude des Tumeurs a Calcitonine

A multifactorial analysis of morphological findings was performed on 153 cases of medullary thyroid carcinoma (MTC). The aim of the study was to utilize histological criteria to discriminate between MTC associated with multiple endocrine neoplasia type 2A (MEN 2A) and that associated with the inherited MTC only syndrome. The presence of fusiform cells associated with several other markers seemed to be more predictive of MEN 2A. A comparison of inherited MTC only and sporadic MTC only showed fusiform cells to be significantly less common in inherited MTC only. These results suggest that the inherited MTC only syndrome is a distinct clinical and morphological entity. Further investigations are needed to confirm the findings and understand its implications.

Sepsis-related cardiogenic shock

To further define cardiovascular abnormalities in patients with septic shock, serial conventional hemodynamic measurements combined with two-dimensional echocardiographic studies were performed at the bedside in 21 patients admitted for an acute episode of sepsis-related circulatory failure. Measurements obtained during the first hours of hospitalization revealed a group of six patients (group 1) with markedly depressed left ventricular function, as evidenced by a low cardiac index (CI) (2.2 +/- 0.8 L/min.m2), reduced left ventricular ejection fraction (LVEF) (21 +/- 8%), and an increased arterial-venous oxygen content difference. Right ventricular systolic function was also severely depressed. These patients were characterized as having sepsis-related cardiogenic shock secondary to profound myocardial depression, which was reversible within 24 to 48 h with inotropic support. The 15 remaining patients (group 2) exhibited an initially increased CI (4.9 +/- 1.8 L/min.m2), with a low systemic vascular resistance. In group 2, LVEF remained within the normal range despite abnormally low peripheral vascular resistance. This finding would suggest the presence of slight to moderate depression of left ventricular systolic function. All patients in this series had a normal left ventricular end-diastolic volume, whether profound myocardial depression was present or not.

Reevaluation of hemodynamic consequences of positive pressure ventilation: emphasis on cyclic right ventricular afterloading by mechanical lung inflation

To examine the cyclic changes in right ventricular (RV) function induced by controlled ventilation, right heart catheterization and two-dimensional echocardiography were combined in a group of 20 patients requiring respiratory support for an episode of acute respiratory failure. Simultaneous measurements of RV pressure (using a modified pulmonary artery catheter), RV stroke output (thermodilution), and RV dimensions (two-dimensional echocardiography), permitted a beat to beat evaluation of RV function throughout the mechanical respiratory cycle. When compared with expiration, lung inflation produced an increase in RV systolic pressure and volume, an increase in RV diastolic volume with an unchanged RV diastolic pressure, and a marked decrease in RV ejection fraction. It is concluded that controlled ventilation altered RV function primarily by increasing RV afterload during the lung inflation period.

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.

Autologous bone marrow transplantation for acute myelocytic leukemia in first remission: a European survey of the role of marrow purging

We analyzed data from 263 patients with acute myelocytic leukemia (AML) autografted in first remission (CR) during the period from January, 1982 to January, 1987 at one of 34 centers in the European Bone Marrow Transplant Group. The median age of patients was 30 years (range, 1 to 65). The median interval between achieving CR and autografting was 5 months (range, 1 to 23). Of the 263 patients, 131 patients received cytoreductive regimens that included total body irradiation (TBI); the remainder received various combinations of cytotoxic drugs. Sixty-nine patients received autologous marrow purged in vitro with mafosfamide, and 194 received unpurged marrow. The median follow-up was 28 months (range, 12 to 97). For patients with standard risk AML in CR1 autografted after TBI (n = 107), the leukemia-free survival (LFS) was higher, and the probability of relapse was lower in recipients of purged than of unpurged marrow (63% versus 34%, P = .05 and 23% versus 55%, relative risk 0.34, P = .005, respectively). The superior results of purging were most obvious in patients autografted within 6 months of achieving CR (probability of relapse, 20% versus 61%, P = .01). Patients with longer intervals between CR and autografting had higher LFS and lower probability of relapse than those autografted early in CR (intervals greater than 9 months, 7 to 9 months, 4 to 7 months, and less than or equal to 3 months: LFS = 56%, 40%, 35%, 27%, P = .007, probability of relapse = 25%, 56%, 59%, 67%, P = .005; respectively). We conclude that marrow purging with mafosfamide may be valuable for patients autografted early in first CR.

A hand-held decision-aid system designed for rural health workers

A great part of the world's population is cared for by rural health workers who are also collecting data for epidemiological studies. These workers have a low level of medical training and are working in a poor technical environment. At the request of an international humanitarian and medical organization (Médecins Sans Frontières), we have developed an integrated (hardware and software) system, TROPICAID, based on a hand-held computer and designed to increase rural health workers' efficiency. The software is easy to use and enables users to get information from an internal data base on 60 drugs. The decision-making module analyzes the patient's parameters (460 different symptoms are recognized) and indicates possible diagnoses (the system knows 210) and relevant treatments. In addition, the system facilitates the collection of medical data for elementary statistical analysis. The computer, which is lightweight (1.5 kg) and compact, runs on battery power for up to a week in normal use. The program which is written in Pascal and data are stored in high-capacity EPROMs. An early trial in Chad with Médecins sans Frontières has shown the value of such a project as well as a few weaknesses to be overcome.