Risk factors for failure of Helicobacter pylori therapy--results of an individual data analysis of 2751 patients

AIM

To study risk factors for failure of Helicobacter pylori eradication treatment.

METHODS

Individual data from 2751 patients included in 11 multicentre clinical trials carried out in France and using a triple therapy, were gathered in a unique database. The 27 treatment regimens were regrouped into four categories.

RESULTS

The global failure rate was 25.8% [95% CI: 24-27]. There was a difference in failure rate between duodenal ulcer patients and non-ulcer dyspeptic patients, 21.9% and 33.7%, respectively (P < 10(-6)). In a random-effect model, the risk factors identified for eradication failure in duodenal ulcer patients (n = 1400) were: to be a smoker, and to have received the group 4 treatment, while to receive a 10 day treatment vs. 7 days protected from failure. In non-ulcer dyspeptic patients (n = 913), the group 2 treatment was associated with failure. In both groups, age over 60 was associated with successful H. pylori eradication. There were less strains resistant to clarithromycin in duodenal ulcer patients than in non-ulcer dyspeptic patients. Clarithromycin resistance predicted failure almost perfectly.

CONCLUSION

Duodenal ulcer and non-ulcer dyspeptic patients should be managed differently in medical practice and considered independently in eradication trials.

[Quality of medical records in the "Medical Information System Program": application of the lot quality assurance sampling method]

BACKGROUND

The aim of this study was to validate a new method of quality control of medical records of the "Medicalisation of Information System Program" (P.M.S.I.) in Limoges university hospital.

METHODS

Lot quality assurance sampling (L.Q.A.S.), developed to meet industrial quality control needs, has been applied. This method allows to give an opinion on the quality of a lot from a sample randomised in this lot. Ten hospital units have been randomised. During three months, these medical units have recoded ten medical units abstracts (R.U.M.) which were randomised each month within their stays. If five or more R.U.M. had been modified on Principal Diagnosis (D.P.), Associated Significant Diagnosis (D.A.S.) or Diagnosis Related Group (D.R.G.), the lot was rejected. The hospital unit had then less 70% R.U.M. of good quality (alpha=5%). The global errors rates were compared to the results of usually performed quality control (1998).

RESULTS

Nine hospital units were included. Hospital units which already had a low quality rate during the 1998 quality control had also an insufficient quality by L.Q.A.S. method. Among these, 33.7 [CI(95%): 21.6-45.8] R.U.M. have been modified. Medical units had a poorer data quality than surgical ones. No statistically significant difference was shown between 1998 errors rates and L.Q.A.S. rates, except for D.P. (p=0.002).

CONCLUSION

L.Q.A.S. is easy to apply, could be repeated more frequently than usual controls, and allows to detect hospital units which require a faster action. This process could be applied to P.M.S.I., in which the search of quality is necessary because of the new cost model which includes secondary D.R.G.

[Bacillary angiomatosis in an adult infected with HIV-1 at an early stage of immunodepression in Abidjan, Côte d'Ivoire]

Human immunodeficiency virus (HIV)-associated bacillary angiomatosis has rarely been described in Africa. We report here the first case in Côte d'Ivoire. Although in industrialised countries bacillary angiomatosis has been described in patients with low CD4 count, this episode occurred in the first year following HIV-seroconversion in an adult patient with more than 500 CD4 cells per cubic millimetre. Symptoms rapidly and totally disappeared under erythromycin treatment, although with a relapse two years after the end of the first episode. In Africa where people living with HIV often present chronic cutaneous lesions, bacillary angiomatosis may be under-diagnosed. Bacillary angiomatosis must be systematically considered in face of lesions similar to Kaposi's sarcoma. Improving knowledge on symptoms of bacillary angiomatosis in Africa should lead to better treatment and a better estimation of its true frequency which may be underestimated.

Correlations of soluble interleukin-2 and tumor necrosis factor type II receptors with immunologic and virologic responses under HAART

We assessed the correlations between some plasma markers of immune activation (soluble receptors of interleukin 2 (sIL2-R) and TNFap75 (sTNFII-R) and usual markers of HIV infection in patients treated with protease-inhibitors (PI). Forty-six PI-naive HIV-1-infected adults were included in a 1-year prospective cohort from the initiation of a P1-containing regimen (M0). Measurements of CD4+cell count, plasma HIV-RNA, sIL2-R and sTNFII-R were performed at M0, M6, and M12. The evolution of sIL2-R from baseline to M12 was significantly different between immunological responders (IR) (CD4+count above 200/mm3 for subject having less than 200 CD4 +/mm3 at inclusion, or increase of at least 50 CD4+/mm3 for others) (58 UI/ml) and non-IR (+28 UI/ml) (P =0.01). The evolution of sTNFII-R between M0 and M12 was significantly different between virological responders (VR) (plasma HIV-1 RNA less than 500 copies/ml at M12) (-2.5 ng/ml) and non-VR (+0.2 ng/ml) (P = 0.02). Our study shows significative correlations between the evolutions of soluble interleukin-2 and TNFR-II receptors and those of CD4+T-lymphocytes or HIV-RNA responses in patients under HAART.

HIV-1-related morbidity in adults, Abidjan, Côte d'Ivoire: a nidus for bacterial diseases

We studied mortality and morbidity in 270 HIV-1-infected adults (60% women, median age 31 years, mean baseline CD4 count 331/mm(3) ) observed in a follow-up that lasted a median 10 months in Côte d'Ivoire. Survival and probability of remaining free from any episode of morbidity at 12 months were 0.80 and 0.50, respectively. Baseline CD4 count <200/mm(3) was the only variable associated with global morbidity and mortality, with hazard ratios of 2.50 and 7.57, respectively. The most frequent causes of morbidity were severe bacterial infections (incidence rate: 26.1 per 100 person-years [py]), followed by oral candidiasis (22.3% py), unexplained weight loss over 10% of baseline body weight (13.3% py), tuberculosis (10.1% py), unexplained chronic diarrhea (9.7% py), and isosporiasis (5.1% py). Nontyphoid Salmonella accounted for 37% of isolated strains during severe bacterial infections, followed by Streptococcus pneumoniae (34%), Escherichia coli (15%), and Shigella species (7%). A significant part of bacterial morbidity occurred in patients with baseline CD4 count > or = 200/mm(3), in whom the incidence rate of bacterial diseases was 21.3% py and the probability of remaining free from any bacterial infection at 12 months was 0.80 (vs. 36.4% py and 0.71 in patients with baseline CD4 count <200/mm(3); p =.07).

Viral load as a primary outcome in human immunodeficiency virus trials: a review of statistical analysis methods

In Human Immunodeficiency Virus infection, several statistical methods are available to analyze viral load (HIV-1 RNA) used as a surrogate outcome in trials of antiretroviral treatments. We compared the most frequently used methods and applied them to one of these trials, where HIV-1 RNA was measured using two lower limits of detection. Methods were reviewed for different properties dealing with validity, interpretation, and handling. Compared to change of HIV-1 RNA at the end of follow-up or HIV-1 RNA area-under-the-curve during follow-up minus baseline, the most attractive methods appeared to be HIV-1 RNA undetectability, HIV-1 RNA reduction at the end of follow-up with censoring adjustment, and mixed linear model on HIV-1 RNA.

[Causes of fever in adults infected by HIV-1. Ambulatory follow-up in the ANRS 059 trial in Abidjan, Ivory Coast]

OBJECTIVE

Describe the causes of fever in HIV-1 infected adults in Abidjan, Ivory Coast.

METHODS

Exhaustive analysis of all the morbid episodes with raise in temperature to above 37.5 degrees C in patients followed-up prospectively, within the framework of the ANRS 059 study from April 1996 to March 1998.

RESULTS

One hundred and four patients presented 269 episodes of fever. At the start of these episodes, the mean CD4 count was of 311/mm3, fever had lasted a mean of 3.4 days and mean body temperature was 38.7 degrees C. The 269 episodes lead to 288 diagnoses: 152 specific etiologic diagnoses and 136 non-specific syndrome diagnoses. Community bacterial infections represented 55% of the specific diagnoses, followed by malaria (16%) and tuberculosis (12%). The mean CD4 count during the bacterial episodes was 208/mm3, in malaria 384/mm3 and in tuberculosis 245/mm3. Non-typhi salmonella, pneumococci and Escherischia coli represented 37%, 32%, and 15% respectively of the bacteria isolated. The mean duration between the first and last day of fever was 8.4 days. This time lapse was superior or equal to 30 days in 22 episodes (8%), 50% of which were mycobacterioses (36% tuberculosis and 14% atypic mycobacterioses). Nineteen episodes (7%) lead to death within a mean delay of 58 days. The first cause of death was atypic mycobacteriosis (26%). Death was significantly associated with a CD4 count < 200/mm3 and to prolongation of fever for more than 30 days.

CONCLUSION

Other than the frequently described role of tuberculosis in HIV morbidity in sub-Saharian Africa, the role of bacterial diseases, responsible for early death, potentially severe, but curable should be underlined. The diffusion of antibiotic treatment algorithms adapted to the principle clinical syndromes encountered, might improve the treatment of adults infected by HIV consulting in sub-Saharian Africa.

Neuropsychologic effects of long-term exposure to pesticides: results from the French Phytoner study

The Phytoner study investigated a possible association between neuropsychologic performances and long-term exposure to pesticides in Bordeaux vineyard workers, most of whom use fungicides. Among the 917 subjects interviewed from February 1997 to August 1998, 528 were directly exposed to pesticides through mixing and/or spraying (mean exposure duration: 22 years), 173 were indirectly exposed through contact with treated plants, and 216 were never exposed. All subjects performed neuropsychologic tests administered at home by trained psychologists. The risk of scoring a low performance on the tests was constantly higher in exposed subjects. When taking into account educational level, age, sex, alcohol consumption, smoking, environmental exposures, and depressive symptoms and when restricting analysis to subgroups, results remained significant for most tests, with odds ratios (OR) exceeding 2. These results point to long-term cognitive effects of low-level exposure to pesticides in occupational conditions. Given the frequency of pesticide use and the potential disabilities resulting from cognitive impairments, further toxicologic and epidemiologic research is needed to confirm these results and assess the impact on public health.

Incidence of primary opportunistic infections in two human immunodeficiency virus-infected French clinical cohorts

BACKGROUND

Clinical guidelines for the prevention of opportunistic infections in human immunodeficiency virus (HIV)-infected individuals have been developed on the basis of natural history data collected in the USA. The objective of this study was to estimate the incidence of primary opportunistic infections in HIV-infected individuals in geographically distinct cohorts in France.

METHODS

We conducted our study on 2664 HIV-infected patients from the Tourcoing AIDS Reference Centre and the hospital-based information system of the Groupe d'Epidémiologie Clinique du SIDA en Aquitaine enrolled from January 1987 to September 1995 and followed through December 1995. We estimated: (1) CD4-adjusted incidence rates of seven primary opportunistic infections in the absence of prophylaxis for that specific infection or any antiretroviral drugs other than zidovudine; and (2) CD4 lymphocyte count decline.

RESULTS

The highest incidence rates for all opportunistic infections studied occurred in patients with CD4 counts < 200/microl. With CD4 counts < 50/microl, the most common opportunistic infections were toxoplasmic encephalitis (12.6 per 100 person-years) and Pneumocystis carinii pneumonia (11.4 per 100 person-years). Mycobacterium tuberculosis was the least common opportunistic infection (< 5.0/100 person-years). Even with CD4 counts > 300/microl, cases of Pneumocystis carinii pneumonia and toxoplasmic encephalitis were reported. The mean CD4 lymphocyte decline per month was 4.6 cells/microl. There was a significant association between HIV risk behaviour and the incidence of cytomegalovirus infection, between calendar year and the incidence of Pneumocystis carinii pneumonia, toxoplasmic encephalitis and Candida esophagitis, and between geographical area and the incidence of Pneumocystis carinii pneumonia and cytomegalovirus infection.

CONCLUSIONS

Geographical differences exist in the incidence of HIV-related opportunistic infections. These results can be used to define local priorities for prophylaxis of opportunistic infections.

Clinical, biologic, and behavioral predictors of early immunologic and virologic response in HIV-infected patients initiating protease inhibitors

Predictors of virologic (plasma HIV RNA viral load [VL] < 500 copies/ml) and immunologic (rise in CD4+ cell count > 50 cells/mm3) response after 4 months of therapy (M4) were studied in 750 HIV-1-infected patients prospectively enrolled at the initiation of a protease inhibitor (PI)-containing regimen. A virologic response was observed in 80% of patients, and an immunologic response was observed in 64%. Sixty-two percent of patients self-reported full adherence to therapy at 1 month of therapy (M1) and M4. In multivariate analysis, a virologic response was more frequent in fully adherent patients (odds ratio [OR] = 2.0; p =.001). An immunologic response was associated with age < 36 years (OR =1.4; p =.03), baseline VL (OR = 1.5 per 1 log10 copies/ml higher; p <.01), decrease in VL at M1 (OR = 1.5 per 1 log10 copies/ml decrease; p <.01), baseline total lymphocyte count (OR = 1.7 per 50% lower; p <.001), and baseline CD4+ cell percentage > or = 20% (OR =1.9; p <.001) but not with adherence to therapy. Full adherence seems to be a major predictor of a virologic response to PI-containing triple therapy. An immunologic response may be possible despite incomplete adherence, at least early in therapy.

Prognostic value of cross-sectional anthropometric indices on short-term risk of mortality in human immunodeficiency virus-infected adults in Abidjan, Côte d'Ivoire

In sub-Saharan Africa where weight loss is very difficult to estimate, cross-sectional anthropometric indicators could be useful to predict human immunodeficiency virus (HIV)-associated mortality. The study objective was to look for threshold values of baseline body mass index, arm muscle circumference, and fat mass to predict the risk of death in HIV-infected adults included in a 1996-1998 trial of early cotrimoxazole chemoprophylaxis in Abidjan, Côte d'Ivoire (COTRIMO-CI-ANRS 059 trial). The authors graphically determined if consecutive anthropometric categories with the closest hazards ratios of the risk of death could be clustered to obtain a unique threshold that distinctly separated two categories. When the threshold values were determined, the authors estimated the hazards ratio of mortality of this two-category model. A significant increase of mortality was observed for a body mass index of < or =20.3 in men (hazards ratio = 2.6; 95% confidence interval (CI): 1.4, 5.0) and of < or =18.5 in women (hazards ratio = 2.2; 95% CI: 1.05, 4.5) and for a fat mass of < or =6% in men (hazards ratio = 4.6; 95% CI: 2.3, 9.4) and of < or =18% in women (hazards ratio = 2.4; 95% CI: 1.2, 4.9). No simple threshold could be identified for arm muscle circumference. In Côte d'Ivoire where chemoprophylaxis of opportunistic infections has recently been recommended to be widely initiated on clinical criteria, such thresholds may help to screen patients with higher risks of mortality.

Determinants of transfusion-associated bacterial contamination: results of the French BACTHEM Case-Control Study

BACKGROUND

Transfusion-associated bacterial contamination (TABC), probably the most frequent transfusion-transmitted infection, may induce serious adverse events. Systematic information and documentation on determinants are lacking.

STUDY DESIGN AND METHODS

The BACTHEM Study is a French matched case-control study assessing TABC determinants. Included were cases of TABC reported in France in a 2-year period, as determined from uniform definitions. Information on recipient-, blood component-, and donor-related potential determinants was collected on site. ORs were estimated by conditional logistic regression.

RESULTS

Of the 158 cases of suspected TABC reported, 41 that involved transfusion with 25 RBCs and 16 platelet concentrates were included. Gram-negative rods accounted for nearly half of the bacteria species involved and for all six deaths. In comparison with the risk of TABC for patients receiving RBCs for anemia, the risk was higher for patients receiving RBCs for pancytopenia (OR, 7.3; 95% CI, 1.3-41.0) and for those receiving platelets for thrombocytopenia (OR, 5.3; 95% CI, 1.2-24.1). Other potential determinants were platelet transfusion for pancytopenia (OR, 4.5; 95% CI, 0.5-40.0), immunosuppressive treatment (OR, 2.8; 95% CI, 0.7-10.6), shelf-life of more than 1 day for platelets or 8 days for RBCs (OR, 2.6; 95% CI, 0.7-9.6), and more than 20 previous donations by donors (OR, 1.9; 95% CI, 0.7-5.3).

CONCLUSION

This first comparative study revealed TABC determinants that suggest approaches for prevention.

Prognostic Value of Plasma Markers of Immune Activation in Patients with Advanced HIV Disease Treated by Combination Antiretroviral Therapy

We assessed the prognostic role of plasma levels of beta2-microglobulin, TNF-alpha, sTNFR-II, and IFN-gamma on the progression to AIDS in patients mostly treated with combination antiretroviral therapies. HIV-1-infected patients with advanced HIV disease (baseline CD4+ cell count between 50 and 250 x 10(6)/L) were included in a prospective cohort followed up for 36 months. In the 113 patients included, 22 first AIDS-defining events were reported. Cumulative probability of AIDS was 12% at M12, 18% at M24, and 20% at M36. Using a Cox model, the baseline level of sTNFR-II (hazard ratio of 3.75 for sTNFR-II > or =10 ng/ml vs < 10 ng/ml, P = 0.01) was associated with progression to AIDS. sTNFR-II remained a prognostic factor before and after the introduction of combinations of antiretrovirals. Whether or not this marker is of value in patients exclusively treated with highly active antiretroviral therapy needs to be assessed in specific studies.

Effect of early chemoprophylaxis with co-trimoxazole on nutritional status evolution in HIV-1-infected adults in Abidjan, Côte d'Ivoire

BACKGROUND

In sub-Saharan Africa, malnutrition is a major complication of HIV disease. Measuring accurately the nutritional benefits of a therapeutic intervention could be an easy-to-monitor secondary outcome.

METHODS

Anthropometric data were analysed from patients participating in a placebo-controlled trial of co-trimoxazole prophylaxis in adults recruited at early stages of HIV-1 infection in Côte d'Ivoire (COTRIMO-CI ANRS 059 trial). Body mass index (BMI), arm muscle circumference (AMC) and percentage of fat mass (FM) were measured at baseline and quarterly during the follow up. Percentage of variation from the baseline value was compared between treatment groups and within the groups using Student t-test.

RESULTS

An improvement of all anthropometric indicators was observed in the first 3 months of follow up in both treatment groups, significant in the co-trimoxazole group (P < or = 0.0006) but not in the placebo group (P > or = 0.06). In the co-trimoxazole group, this improvement was maintained for up to 24 months for BMI (P = 0.007), 21 months for AMC (P = 0.02) and only up to 12 months for FM (P = 0.04). The placebo group had a stable anthropometric status up to the end of the trial. Differences between treatment groups were significant for up to 15 months for BMI and AMC and 12 months for FM.

CONCLUSION

As co-trimoxazole prophylaxis is now recommended in Africa as part of a minimum package of care for HIV-infected symptomatic subjects, the short-term improvement of these anthropometric indicators in adults who start co-trimoxazole prophylaxis should be considered as an effective clinical outcome.

cagA Status and eradication treatment outcome of anti-Helicobacter pylori triple therapies in patients with nonulcer dyspepsia

The differences in eradication rates reported in clinical trials aiming to cure Helicobacter pylori infection cannot be entirely explained by the type of regimen, bacterial resistance, or lack of compliance. Using data from a clinical trial, a logistic regression model was constructed to determine whether cagA status, assessed by PCR, affects the outcome of eradication. Resistance to clarithromycin (10% of the strains) predicted failure perfectly. In the model (n = 156), a cagA-lacking strain (odds ratio [OR] = 2.2; 95% confidence interval [CI], (1.1 to 4.7), tobacco smoking OR = 3.1; 95% CI, 1.3 to 7.0), and a double dose of proton pump inhibitor in the treatment regimen (OR = 0.3; 95% CI, 0.2 to 0.7) were associated with the treatment outcome. The exact role of cagA in the outcome of H. pylori eradication therapy has not been explored. However, the type of histological lesions which it causes in the gastric mucosa may be implicated. Regardless of the mechanism involved, cagA status is a good predictive marker of eradication outcome.

[Lot quality assurance sampling: methods and applications in public health]

Lot Quality Assurance Sampling (LQAS), developed to meet industrial quality control needs, has been applied to health surveys. The WHO used this method to assess immunization coverage. The sampling strategy was developed to classify lots as acceptable or unacceptable. Lot sampling is an efficient, simple and time-efficient procedure for quality assurance. Under certain conditions, efficiency can be improved with double sampling. We describe the method and its theoretical basis and illustrate applications of LQAS in epidemiological surveillance and quality control of medical records. The advantages and disadvantages of this method are presented.

Smoking and eight-year mortality in an elderly cohort

SETTING

The increasing numbers of elderly people highlight the question of smoking effects in this age group.

OBJECTIVE

To investigate whether there is a relationship between smoking and 8-year mortality in a representative elderly cohort aged 65 years and over, residing in the department of Gironde, in the south-west of France.

METHODS

Data were collected by a questionnaire administered during home visits. Every death was systematically recorded during the 8-year follow-up.

RESULTS

The 2786 (99.8%) subjects included in the study were categorised into current smokers, former smokers and never smokers. Mortality was higher (P < 0.0001) in men (39.6%) than in women (29.4%). In men, the risk of mortality was higher (P = 0.01) among current (44.5%) and former smokers (41.4%) than in never smokers (32.5%). The risks were similar in never smokers and former smokers who had stopped more than 20 years previously. Tobacco consumption in pack-years was higher (P = 0.02) in those people who died during the follow-up period than in those who were still alive. Mortality due to respiratory disease (P = 0.008) and lung cancer (P < 0.0001) was significantly higher in current smokers than in former and never smokers. Adjusting for potential confounding factors, smoking remains significantly associated with mortality both in current (relative risk [RR] = 1.7, P < 0.001) and former smokers (RR = 1.3, P = 0.004).

CONCLUSION

These results confirm the consequences of smoking even in the elderly, and raise the question of smoking prevention after 65 years of age.

Preventing mother-to-child transmission of HIV-1 in Africa in the year 2000

OBJECTIVES

Various approaches to preventing mother-to-child transmission (MTCT) of HIV have recently been, or are being, evaluated in developing countries, especially in Africa. New findings from these trials are now becoming available, the implications of which, for population-based intervention programmes, need urgent consideration.

METHOD

A critical review of 18 randomized trials and other relevant studies from developing and industrialized countries.

RESULTS

Most African results relate to trials of antiretroviral agents (ARV). They demonstrate efficacy in reducing transmission in the first 6 months of life with short regimens of zidovudine (ZDV), with or without lamivudine (3TC), and nevirapine (NVP) alone. Preliminary results suggest the long-term efficacy of zidovudine. Antiseptic and nutritional interventions have been shown to reduce maternal and infant mortality and morbidity but not MTCT of HIV. HIV confidential voluntary counselling and testing for pregnant women, a short regimen of peripartum ARV with alternatives to breastfeeding such as early weaning or breast milk substitutes from birth currently represent the best option to reduce MTCTof HIV in Africa. However, the prevention of postnatal transmission requires further research, particularly in view of the consequences of different feeding options and the possibility of post-perinatal exposure prophylaxis of newborns with ARV. Issues relating to the implementation of currently validated strategies are discussed.

The contribution of statistics in the forensic appraisal of post-transfusion contamination by hepatitis C virus

Many patients were contaminated by blood products in the 1980s and early 1990s, a period during which there was no means of detecting hepatitis C virus (HCV) and measures of vigilance in French blood transfusion centers were lacking in rigor, and it has become a real public health issue by now. The blood transfusion centers which produce and distribute the products are liable for such contamination, as long as the expert appraisal has established a link of causality between the transfusion and the contamination. When the viral serologic status (i.e. the contaminating potential) of the donors is not known, experts often resort to indirect evidence, including use of probability estimates calculated according to the following method. The probability (P) that there was at least one contaminating donor among those having provided the blood given to a patient, is calculated using the following formula:P=1.(1.pHCV)(N)where pHCV is the prevalence of subjects who have tested positive for anti-C virus antibodies in a population of blood donors, and N is the number of donors having contributed to the transfusion in question. Although the polymerase chain reaction (PCR) is very sensitive, its threshold, below which weak replication is undetectable, varies depending on the technique used. One study has demonstrated that below a dilution of 10(-4), RNA is no longer detected by the majority of laboratories. The specificity of PCR is not flawless either, since false-positive results are found, probably resulting from contamination of the samples. Considering that 0.10% is a reasonable approximation of the prevalence of subjects who had anti-HCV antibodies that were detectable by recombinant immunoblot assay during that period, one can calculate the probability that there is a contaminating donor among the blood donors who contributed to the product that was administered and determine a curve.

Dosimetric characterisation of a new production of MgB4O7:Dy,Na thermoluminescent material

Thermoluminescent dosimetric characteristics of MgB4O7:Dy,Na are presented. MgB4O7:Dy,Na is a newly prepared TL material with attractive features for dosimetric applications, such as near-tissue equivalence, simple glow curve, high sensitivity and low fading. The dosimetric properties of this material examined in this study include glow curve shape, TL sensitivity, annealing procedure, photon dose response, minimum detectable dose, precision of TL measurements, reproducibility, energy response and fading characteristics.

[HIV infection in Africa. Clinical and therapeutical research]

A MAJOR HEALTH PROBLEM: Human Immunodeficiency Virus (HIV) infection is a major public health problem in sub-Saharan Africa and the care of HIV-infected patients is limited by the lack of resources. Clinical research can play a major role to assess the benefit of preventive and/or curative measures adapted to the context of these countries. To illustrate advances and gaps in HIV/AIDS clinical research in Africa, we explored three issues relevant to this research: opportunistic infections in adults, mother-to-child transmission of HIV and the ethical questions.

EPIDEMIOLOGY

Epidemiological African studies have shown: the omnipresence of tuberculosis, first cause of death among HIV+ patients; the frequency of bacterial infections, first cause of serious morbidity and second cause of death; the high frequency of toxoplasmosis, cryptococcal meningitis, isosporiasis, cryptosporidiasis, and other infectious syndromes of unknown etiology. More research efforts need to be done for improving tuberculosis diagnosis, compliance to treatment (evaluation of Directed Observed Therapy), resistance to treatment and primary chemoprophylaxis which has shown clear short term benefit but median term interest remains to be demonstrated. Chemoprophylaxis of opportunistic infections other than tuberculosis needs also to be evaluated: cotrimoxazole reduces the short term mortality of HIV+ patients with tuberculosis and the early serious morbidity of HIV+ patients without tuberculosis.

TRANSMISSION

Mother-to-child transmission of HIV can occur during pregnancy, during delivery and the postnatal period by breastfeeding, a common practice in Africa. The overall risk of vertical transmission is estimated to be 30% but the attributable part of breastfeeding needs to be further explored. Beyond the prevention of sexual transmission of HIV among childbearing women and family planning for HIV+ women, interventions aimed to reduce mother-to-child transmission depend on the availability or not of a proposing and realising an HIV counselling and testing: antiretroviral treatments and/or breastfeeding alternatives which reduce efficaciously transmission require HIV testing, while vaginal disinfection and vitamin supplementation whom efficacy needs to be demonstrated do not.

PREVENTION

Prevention of mother-to-child transmission and care of HIV+ adults in the area of opportunistic infections are feasible in Africa with an acceptable cost. This requires first to train and inform health care providers and the populations. Lots of uncertainties in these areas are likely to be alleviated by reinforcing clinical and therapeutic research of good quality including the questions of antiretroviral treatment. Ethical issues raised by the design and conduct of clinical research in Africa need a positive thinking to face the HIV African pandemic.

[Effect of dapsone on survival in HIV infected patients: a meta- analysis of finished trials]

BACKGROUND

The aim of the study was to estimate the effect of dapsone on survival in HIVinfected patients.

METHOD

The method was a metaanalysis. Data searches used MEDLINE, AIDS TRIALS, and AIDS DRUGS databases from 1983 to January 1996, clinical trials registries of appropriate collaborative research groups, abstract books of International Conferences on AIDS and infectious diseases between 1988 and 1996, references listed within selected articles and active experts in HIV infection. Were considered as eligible: randomized clinical trials, conducted in adults, with one arm evaluating dapsone as prophylactic agent for Pneumocystis Carinii Pneumonia (PCP). Each primary investigator was asked to provide the most recent aggregated study data by completing a standardized questionnaire and to provide files of individual patient data whenever possible.

RESULTS

Overall, 17 trials (4343 patients) were eligible for the metaanalysis. The analysis of all available aggregated data included 16 trials (4267 patients) and showed no deleterious effect of dapsone on survival: OR=1.11, 95% Confidence Interval (CI)=0.961.29. There was no evidence of heterogeneity among studies (p=0.50). The analysis of individual data included 10 trials (3115 patients) (OR for aggregated data from those trials=1.10, CI=0. 931.29) and confirmed the absence of deleterious effect of dapsone on survival: stratified Hazard Ratio=1.12, CI=0.991.27 (logrank test: p=0.08). In this subsample, there was evidence of a deleterious effect of dapsone used as secondary prophylaxis. However, this result did not remain when the trial reporting the greatest negative effect of dapsone on survival was omitted.

CONCLUSION

Dapsone may be used safely as a primary prophylactic regimen for PCP or toxoplasmosis. However, no definitive recommendation can be made for the use of dapsone as secondary PCP prophylaxis.

Increased occurrence of depression in psychosis-prone subjects: a follow-up study in primary care settings

A follow-up survey was performed with a network of general practitioners (GPs) to examine whether a higher proneness for psychosis predicts a greater incidence of depression in subjects with no history of mood disorder. At the first stage of the survey (T1), a self-report questionnaire exploring delusional ideation (Peters et al. Delusional Inventory [PDI-21]) was administered to the patients of the GPs. Information on psychiatric status at the baseline and conclusion of the 12-month follow-up period was provided by the GPs. The present study was restricted to 425 subjects with no lifetime history of depression. An incident depression was diagnosed in 18 subjects. Most items exploring delusional beliefs and hallucinations were more frequently endorsed by subjects with incident depression. Subjects with a PDI-21 score above the 90th percentile at T1 were nine times more likely to present with an incident depression during the follow-up period than those with PDI-21 scores below the 10th percentile. Psychosis proneness is associated with a greater risk for depression, suggesting that a continuum of vulnerability may exist between affective disorder and nonaffective psychosis.