Prevalence of COVID-19 at the Wahgnion-Gold mining site in Burkina Faso and use of RT-PCR initial cycle threshold to monitor the dynamics of SARS-CoV-2 load

Background: To control the spread of coronavirus disease-19 (COVID-19) caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), it is necessary to adequately identify and isolate infectious patients particularly at the work place. Real time polymerase chain reaction (RT-PCR) assay is the recommended confirmatory method for the diagnosis of SARS-CoV-2 infection. The aim of this study was to determine the prevalence of SARSCoV-2 infection in Burkina Faso and to use the initial cycle threshold (Ct) values of RT-PCR as a tool to monitor the dynamics of the viral load. Methodology: Between September 2021 and February 2022, oropharyngeal and/or nasopharyngeal swab samples of consecutively selected COVID-19 symptomatic and apparently healthy workers from the Wahgnion mining site in the South-western Burkina Faso who consented to the study were collected according to the two weeks shift program and tested for SARS-CoV-2 using RT-PCR assay. Patients positive for the virus were followed-up weekly until tests were negative. Association of the initial RT-PCR Ct values with disease duration was assessed by adjusted linear regression approach. Two-sided p value < 0.05 was considered statistically significant. Results: A total of 1506 (92.9% males) participants were recruited into the study, with mean age and age range of 37.18.7 and 18-68 years respectively. The overall prevalence of SARS-CoV-2 infection was 14.3% (216/1506). Of the 82 patients included in the follow-up study, the longest duration of positive RT-PCR test, from the first positive to the first of the two negative RT-PCR tests, was 33 days (mean 11.6 days, median 10 days, interquartile range 8- 14 days). The initial Ct values significantly correlated with the duration of RT-PCR positivity (with ß=-0.54, standard error=0.09 for N gene, and ß=-0.44, standard error=0.09 for ORF1ab gene, p<0.001). Participants with higher Ct values corresponding to lower viral loads had shorter viral clearance time than those of lower Ct values or higher viral loads. Conclusion: Approximately 1 out of 7 tested miners had SARS-CoV-2 infection and the duration of their RT-PCR tests positivity independently correlated with the initial viral load measured by initial Ct values. As participants with lower initial Ct values tended to have longer disease duration, initial RT-PCR Ct values could be used to guide COVID-19 patient quarantine duration particularly at the work place.

Contexte: Pour contrôler la propagation de la maladie à coronavirus 19 (COVID-19) causée par le syndrome respiratoire aigu sévère coronavirus-2 (SRAS-CoV-2), il est nécessaire d'identifier et d'isoler de manière adéquate les patients infectieux, en particulier sur le lieu de travail. Le test de réaction en chaîne par polymérase en temps réel (RT-PCR) est la méthode de confirmation recommandée pour le diagnostic de l'infection par le SRAS-CoV-2. Le but de cette étude était de déterminer la prévalence de l'infection par le SRAS-CoV-2 au Burkina Faso et d'utiliser les valeurs du seuil initial du cycle (Ct) de la RT-PCR comme outil de suivi de la dynamique de la charge virale. Méthodologie: Entre septembre 2021 et février 2022, des écouvillonnages oropharyngés et/ou nasopharyngés de travailleurs symptomatiques COVID-19 et apparemment en bonne santé sélectionnés consécutivement du site minier de Wahgnion dans le sud-ouest du Burkina Faso qui ont consenti à l'étude ont été prélevés selon les deux programme de quart de semaines et testé pour le SRAS-CoV-2 à l'aide d'un test RT-PCR. Les patients positifs pour le virus ont été suivis chaque semaine jusqu'à ce que les tests soient négatifs. L'association des valeurs Ct initiales de la RT-PCR avec la durée de la maladie a été évaluée par une approche de régression linéaire ajustée. Une valeur p bilatérale < 0,05 a été considérée comme statistiquement significative. Résultats: Un total de 1506 participants (92,9% d'hommes) ont été recrutés dans l'étude, avec un âge moyen et une tranche d'âge de 37,1 à 8,7 ans et de 18 à 68 ans, respectivement. La prévalence globale de l'infection par le SRAS-CoV-2 était de 14,3% (216/1506). Sur les 82 patients inclus dans l'étude de suivi, la plus longue durée de test RT-PCR positif, du premier test positif au premier des deux tests RT-PCR négatifs, était de 33 jours (moyenne 11,6 jours, médiane 10 jours, intervalle interquartile 8-14 jours). Les valeurs Ct initiales étaient significativement corrélées à la durée de positivité de la RT-PCR (avec ß=-0,54, erreur standard=0,09 pour le gène N et ß=-0,44, erreur standard=0,09 pour le gène ORF1ab, p<0,001). Les participants avec des valeurs de Ct plus élevées correspondant à des charges virales plus faibles avaient un temps de clairance virale plus court que ceux avec des valeurs de Ct plus basses ou des charges virales plus élevées. Conclusion: Environ 1 mineur testé sur 7 était infecté par le SRAS-CoV-2 et la durée de la positivité de ses tests RTPCR était indépendamment corrélée à la charge virale initiale mesurée par les valeurs Ct initiales. Comme les participants avec des valeurs Ct initiales inférieures avaient tendance à avoir une durée de maladie plus longue, les valeurs Ct initiales de la RT-PCR pourraient être utilisées pour guider la durée de la quarantaine des patients COVID19, en particulier sur le lieu de travail.

24-Month adherence, tolerance and efficacy of once-a-day antiretroviral therapy with didanosine, lamivudine, and efavirenz in African HIV-1 infected children: ANRS 12103/12167.

BACKGROUND: There is no data on long-term benefit of once-a-day antiretroviral therapy (ART) with combination of DDI, 3TC and EFV to allow its use in future therapeutic strategies. OBJECTIVES: To assess 24-month immuno-virological, adherence, tolerance, and effectiveness of a once-a-day ART with DDI, 3TC and EFV. METHODS: A phase 2 open trial including 51 children aged from 30 months to 15 years, monitored a once-a-day regimen for 24 months from 2006 to 2008 in the Departement de Pediatrie du CHUSS, at Bobo-Dioulasso in Burkina Faso. We tested immunological and virological response, adherence, tolerance and resistance of the treatment. RESULTS: Children with CD4 >25% at 24 months were 67.4% (33/49) CI 95% [54%, 80%]. The proportion of children with viral plasma RNA <300 cp / ml at 24 months of treatment was 81.6 % (40/49) CI [68.0% 91.2%]. Good adherence was obtained with more than 88% adherence > 95% over the 24 months. Drugs were well tolerated. CONCLUSIONS: Given the limited number of antiretroviral drugs available in Africa and the inadequacy of laboratory monitoring in support program, once-a-day treatment and especially the DDI-based combination strategies could be an attractive operational option.

[Epidemiological situation of yellow fever in Burkina Faso from 2003 to 2008]. / Situation épidémiologique de la fièvre jaune au Burkina Faso de 2003 à 2008.

Despite the existence of antiamaril vaccine in the routine Expanded Program of Immunization (EPI) in Burkina Faso, yellow fever cases still occur in the country. In collaboration with WHO, the national health authorities set up a surveillance system through the national reference laboratory in Centre Muraz (Bobo-Dioulasso). All samples of feverish icterus cases of the 63 health districts of the country were analysed in this lab for M Immunoglobulin using Enzyme Linked Immunosorbent Assay (Elisa). Positive Elisa samples were sent to Pasteur Institute of Dakar (Senegal) for confirmation using a Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) assay. From 2003 to 2005, the number of confirmed cases of yellow fever was respectively of 1/413 (0.24%), 14/616 (2.27%) and 19/618 (3.07%). This increasing of the proportion was statistical different. Then, from 2006 to 2008, the confirmed case proportion was respectively 0.35%, 0.27 and 0.54% without significant difference (P = 0.69). The entomological investigations conducted in 2004 in Bobo-Dioulasso showed that the water pots constitute 48.11% mosquitoes lodgings, followed by metal drums with a strong representation of Culex quinquefasciatus (48.7%), followed by Aedes aegypti (43.3%), as vectors in domestic areas with sectorial variations. These results suggest that more attention must be paid by the national health authorities and international community regarding this disease.

First molecular epidemiology study of Mycobacterium tuberculosis in Burkina Faso.

We conducted a molecular epidemiology study on 120 Mycobacterium tuberculosis isolates from patients presenting pulmonary tuberculosis (TB) in Burkina Faso. Classical antibiogram studies and genetic characterization, using mycobacterial interspersed repetitive-unit-variable-number tandem-repeat (MIRU-VNTR) typing and spoligotyping, were applied after culture. Molecular analysis of specific signatures showed that all TB cases reported in this study were caused by M. tuberculosis and identified no Mycobacterium bovis or Mycobacterium africanum isolates. This result is unexpected, as M. africanum strains were reportedly the etiologic agent in 20% of TB cases 2 decades ago. The comparison of spoligotypes from Burkina Faso with an international spoligotype database (SpolDB4) showed that the majority of isolates belong to major clades of M. tuberculosis (Haarlem, 9%; Latin American-Mediterranean, 30%; and T, 20%). The predominant group of isolates (30%) corresponds to spoligotype 61, described in Cameroon as the "Cameroon family." In Burkina Faso, as in Cameroon, this family could be associated with recent transmission of TB, suggesting a recent expansion in West Africa. Our data suggest a low level of primary drug resistance that may be a positive result of the Directly Observed Therapy Shortcourse program. Besides, based on spoligotyping plus MIRU-VNTR, data showed a high number of clusters in our sample, suggesting a high level of recent TB transmission in Burkina Faso. Nevertheless, an important genetic polymorphism was observed in this country, reflecting an endemicity situation where the control of TB would have less impact in the main towns.

Alteration in CD29(high) CD4(+) lymphocyte subset is a common feature of early HIV disease and of active tuberculosis.

Peripheral CD4 T-cell depletion has been observed in human immunodeficiency virus (HIV)-negative patients with pulmonary tuberculosis (TB). To investigate more accurately this alteration, we studied peripheral blood CD45RA(+) and CD29(high) CD4 subsets in 79 TB patients with (HIV(+)TB(+)) or without (HIV(-)TB(+)) HIV infection, 85 HIV-infected patients without TB (HIV(+)TB(-)), and 43 healthy controls, all living in West Africa. The high proportion of CD4(+)CD29(high) T cells observed in controls was dramatically decreased in CDC-A stage HIV(+)TB(-) patients. CD45RA(+) CD4(+) T cells were depleted during the CDC-B stage. Both the percentage and the absolute count of CD29(high)CD4(+) T cells were decreased in HIV(-)TB(+) and HIV(+)TB(+) patients versus controls, but CD45RA(+)CD4(+) T cells were not decreased in TB patients without HIV-infection. Although distinct alterations in the CD4(+) T-cell homeostasis are involved in TB(-) versus HIV-infected subjects, our data suggest that the CD29(+)CD4(+) T-cell depletion observed during the early HIV disease contributes to the risk of active TB, by reducing the pool of T cells able to relocalize to the sites of the M. tuberculosis multiplication.

[Simultaneous resistance to rifampicin and isoniazid in patients with pulmonary tuberculosis]. / Résistance simultanée à la rifampicine et à l'isoniazide chez des malades atteints de tuberculose pulmonaire.

Percentages of primary and acquired resistance to anti-tuberculosis drugs provide an epidemiological indicator useful for assessing national anti-tuberculosis programs. Rifampicin and isoniazide are widely used in countries with a high prevalence of tuberculosis. In tropical Africa, these drugs are the mainstay treatment for tuberculosis, used both in the initial and long-term regimens. Simultaneous resistance to these two antibiotics would seriously jeopardize therapeutic efficacy. We studied simultaneous rifampicin and isoniazide resistance in patients hospitalized for tuberculosis in the respiratory disease unit of the Treichville University hospital in Abidjan, Ivory Coast. Mycobacterium tuberculosis was isolated in 8 patients. All the strains isolated were resistant to streptomycin. History taking revealed that resistance was observed at the initial prescription in 6 cases. A notion of contagion was present in 4 cases. Six patients were HIV-positive. Surveillance of resistance to anti-tuberculosis drugs is helpful in detecting early changes which could compromise the efficacy of the therapeutic scheme.

Evaluation of a quantitative determination of CD4 and CD8 molecules as an alternative to CD4+ and CD8+ T lymphocyte counts in Africans.

In the developed word, monitoring HIV-infected patients is routinely determined by CD4+ T lymphocyte absolute counts. The reference procedure, flow cytometry, is expensive, requires sophisticated instrumentation and operators with specific training. Due to these limitations, CD4 counting is often unavailable in developing countries. The Capcellia assay is an enzyme-linked immunoassay for quantitative determination of CD4 and CD8 molecules. We evaluated this method in West Africa on blood samples collected from 39 HIV-uninfected and 44 HIV-infected adult subjects. CD4 concentration ranges were determined according to the clinical stages of the disease. We then studied the relationship between the two methods in the HIV-infected patients. The Spearman's rank correlation was 0.61 (95% confidence interval: 0.38-0.76, P < 0.0001). Nevertheless, determination of limits of agreement revealed discrepancies between the two methods, especially for CD4 counts > 0.4 x 10(9)/l, which are discussed. We conclude that the Capcellia assay is a convenient means to determine the immunodepression level where flow cytometric instrumentation is unavailable, and can be complementary to CD4 T lymphocyte enumeration.

Relationship between interleukin-5 production and variations in eosinophil counts during HIV infection in West Africa: influence of Mycobacterium tuberculosis infection.

Eosinophils are important effectors of the non-specific immune response and we studied whether perturbations in the production of the type 2 cytokine, interleukin-5 (IL-5), could account for the variations in eosinophil counts observed in human immunodeficiency virus (HIV) infection. HIV-infected patients without helminthiasis were investigated in a cross-sectional study in West Africa. Eosinophil counts were significantly higher in CDC-B patients than in controls, but were dramatically decreased at the CDC-C stage. Phorbol 12-myristate 13-acetate (PMA)+ ionomycin-induced IL-5 production by peripheral blood mononuclear cells (PBMC) was decreased from the A stage of the disease, and significant correlations were observed between IL-5 production and eosinophil counts in tuberculosis (TB)-negative HIV-1-positive, TB-positive HIV-1-positive and TB-positive HIV-negative patient groups. Nevertheless, the production of IL-5 was not decreased in HIV-positive patients with TB, in contrast to HIV-positive patients without TB presenting with the same ranges of CD4+ counts. Our data suggest that, during HIV infection, the impairment in IL-5 production is one of the factors associated with the 'paradoxal' eosinopenia observed in tropical areas, but that IL-5 production during active TB is compensated by cellular subsets, yet to be identified.

PIP: Eosinophils are important effectors of nonspecific immune response, with eosinophilia being a classic sign of helminthic infection, allergies, and some inflammatory processes. The authors explored whether perturbations in the production of interleukin-5 (IL-5) could account for the variations in eosinophil counts seen in HIV infection. The 491 study subjects were recruited between 1993 and 1995 in Bobo-Dioulasso, Burkina Faso. Eosinophil counts were significantly higher in CDC-B AIDS patients than in controls, but were dramatically lower among CDC-C stage subjects. Phorbol 12-myristate 13-acetate (PMA)+ionomycin-induced IL-5 production by peripheral blood mononuclear cells (PBMC) was decreased from the A stage of the disease, and significant correlations were observed between IL-5 production and eosinophil counts in tuberculosis (TB)-negative HIV-1-positive, TB-positive HIV-1-positive, and TB-positive HIV-negative patient groups. The production of IL-5 was not decreased among HIV-positive patients with TB, in contrast to HIV-positive patients without TB presenting with the same ranges of CD4+ counts. These data suggest that during HIV infection, impairment in IL-5 production is one factor associated with the paradoxal eosinopenia observed in tropical areas, but that IL-5 production during active TB is compensated by as yet unidentified cellular subsets.

Potential source of human exposure to Mycobacterium bovis in Burkina Faso, in the context of the HIV epidemic.

OBJECTIVE: To identify potential sources of human Mycobacterium bovis infection in Bobo-Dioulasso, Burkina Faso. METHODS: A tuberculin survey among 174 cattle was performed. Mycobacteriologic identification in 64 samples of pooled milk, and in 199 tissue samples collected from the slaughterhouse of Bobo-Dioulasso, Burkina Faso, was also done. We retrospectively analyzed the distribution of tuberculosis (TB) cases on 1140 clinical records according to professional occupation and to ethnic group. The frequency of pulmonary and extrapulmonary TB was related to potential exposure and route of transmission of M. bovis from animals. RESULTS: Out of six herds (total 170 bovines), only one was free of any positive tuberculin test. Among 199 bovines which had been slaughtered over four consecutive nights, 38 (19%) had morphologic lesions suggestive of TB; 17 (45%) of those were positive for acid-fast bacilli by microscopic examination on one of their lesions, and 20 samples (53%) presented a positive culture for a pathogenic mycobacterium, including M. bovis and M. tuberculosis. In the retrospective analysis, Peuls more frequently had a pulmonary form of disease. This may be related to the route of transmission. CONCLUSIONS: Attention has to be paid to human TB of bovine origin in Burkina Faso. The identification of M. tuberculosis in milk and in tissue samples raises the question of the transmission of TB from humans to cattle.

A proposal for basic management of HIV disease in west Africa: use of clinical staging and haemogram data.

Our objective was to propose a strategy to screen HIV-infected African people for biological immunodeficiency easily. In a cross-sectional study, we analysed the patterns of diseases and of CD4 counts among 266 HIV-infected adults. Peripheral facial paralysis and chronic cutaneo-mucous diseases were the earlier B-stage diseases. Pulmonary tuberculosis was close to B-stage diseases, and chronic diarrhoea was borderline between B and C stages. Cachexia was the most frequent C-stage symptom (47.8%). Ninety per cent of CDC-C stage people had CD4 counts below 350/microliter, whereas only 75% had CD4 counts below 200/microliter. Regression analysis identified the lymphocyte count, clinical stage and platelet count as predictors of CD4 count below 350/microliter. A simple score (lymphocyte count < or = 2500/microliter and clinical stage > or = B) is proposed to determine this CD4 threshold (positive predictive value: 83%) and to determine those patients needing treatment to prevent wasting and opportunistic infections.

PIP: Findings are presented from a cross-sectional study conducted in 1995 in Bobo-Dioulasso, Burkina Faso, in which the patterns of diseases and CD4 counts among 266 HIV-infected adults of mean age 33 years were analyzed. The bioclinical spectrum of subjects' HIV disease is described and a simple alternative proposed to CD4 enumeration for screening and monitoring HIV-infected Africans. Dermatological symptoms and diarrhea were the most frequent signs associated with B-stage disease, while cachexia and digestive candidosis were the most frequent AIDS-defining diseases (ADD). Peripheral facial paralysis and cutaneo-mucous diseases were associated with weak immune deficiency. Pulmonary tuberculosis (TB) was close to B-stage diseases, and chronic diarrhea was borderline between B and C stages. Cachexia was the most frequent C-stage symptom (47.8%). 90% of CDC C-stage subjects had CD4 counts of less than 350 per mcl, while only 75% had CD4 counts under 200/mcl. Regression analysis identified the lymphocyte count, clinical stage, and platelet count as predictors of CD4 count below 350/mcl. A lymphocyte count of less than or equal to 2500/mcl and clinical stage of B or higher is proposed to determine the CD4 threshold and to determine those patients in need of treatment to prevent wasting and opportunistic infections.

Lack of direct correlation between CD4 T-lymphocyte counts and induration sizes of the tuberculin skin test in human immunodeficiency virus type 1 seropositive patients.

SETTING: The study was conducted in Bobo-Dioulasso, Burkina Faso, where Mycobacterium tuberculosis infection and human immunodeficiency virus type 1 (HIV-1) infection are prevalent. OBJECTIVE: To identify proportions of representative (test) populations who are reactive to the tuberculin skin test, and to study the relationship between CD4 T-lymphocyte counts and the induration size of the tuberculin skin test in these groups. DESIGN: A group of 435 healthy students was tuberculin skin tested in order to evaluate the intensity of skin testing in a 'normal' population. The study group consisted of 195 subjects with or without tuberculosis, and with or without HIV-1 infection, who received a tuberculin skin test and a CD4 T lymphocyte count on the same day. RESULTS: In total, 90% of the control (nontuberculous, HIV negative) subjects, 32% of the HIV-1 seropositive subjects, 76.5% of the tuberculous patients and 57% of the tuberculous HIV-1 seropositive patients were tuberculin positive. There was no direct correlation between the induration size of reactions to the tuberculin skin test and CD4 T-lymphocyte count in these study groups using linear regression analysis. CONCLUSION: In vivo skin testing using tuberculin yields clinically significant information on the degree of immunodeficiency which is different from that of CD4 T-lymphocyte counts. The tuberculin skin test should therefore be used as an independent marker of the weakened immunological status of HIV-1 seropositive subjects.

Immunoblot analysis for serodiagnosis of tuberculosis using a 45/47-kilodalton antigen complex of Mycobacterium tuberculosis.

We evaluated the immunoglobulin G (IgG) antibody response to the 45/47-kDa secreted protein of Mycobacterium tuberculosis by immunoblot assay, to assess its potential value for serological diagnosis. Control subjects consisted of healthy volunteers with negative or positive tuberculin skin tests. Most (>98%) scored negative in an immunoblot test when the sera were analyzed at a 1:400 dilution. Approximately 40% of sera (diluted 1 in 400) from tuberculous patients (positive smears) recognized the antigen complex. The sensitivity of the test for patients suffering from extrapulmonary tuberculosis was similar to that for patients suffering from pulmonary tuberculosis but who had negative smears. The frequency of positive reactions among the patients suffering from other pulmonary diseases was similar to that among the control subjects. In tuberculous patients infected with human immunodeficiency virus, the sensitivity of the immunoblot test was significantly lower. Thus, this test based on an antigen complex used in an immunoblot assay to detect the presence of IgG antibody has a specificity of 98% and a sensitivity of 40%. The simultaneous use of different purified antigens, selected at the same high specificity level, may improve the sensitivity of such an assay.

CD4+ T-lymphocyte counts in HIV infection: are European standards applicable to African patients?

CD4+ lymphocyte count (CD4+ LC) is a widely used marker of Human Immunodeficiency Virus (HIV) immune impairment. Physiological lymphocytosis is frequently encountered in Africans. Therefore, we tried to determine if given CD4+ LC levels are of similar significance in European versus African HIV-infected individuals. Lymphocyte phenotyping of 750 HIV-infected adults was retrospectively analyzed. Three hundred and seventy patients were consecutively selected in Paris, France; 185 in Abidjan, Côte d'Ivoire; and 195 in Bobo-Dioulasso, Burkina Faso. In the three settings, lymphocyte phenotyping was performed by flow cytometry using similar protocols. Data from Abidjan and Bobo-Dioulasso were combined on the basis of geographic proximity and contrasted with those from Paris. Geometric mean levels of Total Lymphocyte Count (TLC), CD4+ LC, CD8+ lymphocyte count (CD8+ LC), and CD4:CD8 ratio, adjusted for percentage of CD4+ T-cells (%CD4+), were compared between Africans and Europeans. For a given %CD4+, TLC and CD4+ LC but not CD8+ LC tended to be about one third higher in West African than in French adults (p < 0.0001). Approximate equivalencies of absolute CD4+ counts in French and West African HIV-infected adults suggest that where thresholds of 200 and 500 CD4+ cells/microliter are applied in Europe, it might be appropriate to apply a threshold of approximately 250 and 700 CD4+ cells/microliter in West Africa, respectively. Establishing indicators of progression of HIV infection with locally appropriate thresholds may represent important steps toward improvement of HIV disease management in Africa.

PIP: CD4+ T-lymphocyte count (CD4+ LC) is a widely used marker of HIV immune impairment. The authors explored whether given CD4+ LC levels have the same significance in European HIV-infected individuals as they do in similarly infected Africans. 370 HIV-infected adults were consecutively selected in Paris, France, 185 in Abidjan, Cote d'Ivoire, and 195 in Bobo-Dioulasso, Burkina Faso, to undergo retrospective lymphocyte phenotyping using flow cytometry. Data from Abidjan and Bobo-Dioulasso were combined on the basis of geographic proximity and contrasted with those from Paris. Geometric mean levels of total lymphocyte count (TLC), CD4+ LC, CD8+ LC, and CD4:CD8 ratio, adjusted for the percentage of CD4+ T-cells, were compared between Africans and Europeans. For a given percent CD4+, TLC and CD4+ LC, but not CD8+ LC, tended to be about one-third higher in West African than in French adults. Approximate equivalencies of absolute CD4+ counts in French and West African HIV-infected adults suggest that where thresholds of 200 and 500 CD4+ cells/mcl are applied in Europe, thresholds of approximately 250 and 700 CD4+ cells/mcl may be more suitable in West Africa. Establishing indicators of the progression of HIV infection with locally appropriate thresholds may lead to the improved management of HIV disease in Africa.

A study of Toxoplasma and Cytomegalovirus serology in tuberculosis and in HIV-infected patients in Burkina Faso.

Seroreactivity to Toxoplasma gondii (Tg) and to Cytomegalovirus (Cmv) was compared between symptomatic HIV-infected patients (40 with pulmonary tuberculosis and 38 with AIDS) and HIV-seronegative patients (40 tuberculosis patients and 30 healthy patients), in an urban area of Burkina Faso. Prevalence of IgG antibodies to Tg antigens (> 50.0%) did not differ amongst the four groups, but tuberculosis HIV+ patients and AIDS patients showed more higher titers of Tg antibodies more often than healthy patients (p < 0.05 and p < 0.005, respectively). Prevalence of specific IgG to Cmv was higher in tuberculosis HIV-seronegative patients (97.5%) and in AIDS patients (100%) than in healthy patients (82%; p < 0.03 and p < 0.001, respectively). Higher Cmv antibodies titers were found in relation to AIDS but also to tuberculosis. Tuberculosis HIV+ as tuberculosis HIV-patients showed higher Cmv antibodies titers than healthy patients (p < 0.002 and < 0.02 respectively). These data emphasize the need for taking into account the risk of Tg reactivation during the follow-up of HIV infected patients in Burkina Faso and suggest possible relationships between Cmv and tuberculosis reactivations.

Marqueurs biologiques d'immunopression chez les malades tuberculeux seropositifs

La double infection du VIH et de la tuberculose en Afrique de l'Ouest connait aujourd'hui une augmentation considerable. Ainsi une etude a ete menee en vue d'evaluer le degre d'atteinte immunitaire des patients seropositifs lors du diagnostic de la tuberculose ; d'ameliorer la definition du SIDA chez les patients et de proposer les marqueurs alternatifs aux marqueurs classiques d'immunodepression. Lors du diagnostic de la tuberculose seuls 33 pour cent des patients presentaient biologiquement du SIDA