Risk factors for negative sputum acid-fast bacilli smears in pulmonary tuberculosis: results from Dakar, Senegal, a city with low HIV seroprevalence.

SETTING: Two teaching hospitals in Dakar, Senegal, a West African country with a low prevalence of human immunodeficiency virus (HIV) infection. OBJECTIVE: To determine whether patients with HIV-associated pulmonary tuberculosis have fewer acid-fast bacilli (AFB) in their sputum as assessed by routine microscopy, and to correlate the findings with systematically obtained clinical, radiographic and laboratory variables. DESIGN: Prospective study from November 1995 to October 1996 of 450 consecutive patients diagnosed with pulmonary tuberculosis. RESULTS: Tuberculosis was diagnosed in 380 patients (84.4%) by positive bacteriology, in 61 (13.6%) by a favorable response to anti-tuberculosis chemotherapy, and in nine (2.0%) by the presence of a miliary radiographic pattern. Forty (8.9%) patients were HIV-seropositive. AFB-negative smears were found in 14/40 (35.0%) of the HIV-seropositive patients with pulmonary tuberculosis compared with 71/410 (17.3%) of the seronegative patients (risk ratio [RR] = 2.02, 95% confidence interval [CI] 1.26-3.24, P = 0.01). Multivariate analysis revealed that AFB smear negativity was associated with absence of cavitation (P = 0.002), lack of cough (P = 0.005), the presence of HIV seropositivity (P = 0.02), a CD4+ cell count above 200/mm3 (P = 0.02), and age over 40 years (P = 0.03). CONCLUSIONS: Compared with HIV-seronegative patients with pulmonary tuberculosis, seropositive patients in Dakar, Senegal, are more likely to have negative sputum-AFB smears. This phenomenon has now been observed in seven of eight sub-Saharan African countries with varying HIV seroprevalence from which reports are available.

A simple clinical and paraclinical score predictive of CD4 cells counts below 400/mm3 in HIV-infected adults in Dakar University Hospital, Senegal.

In industrialized countries the decision to start co-trimoxazole (CMX) prophylaxis of HIV-related opportunistic infections is based on the CD4+ cell count. The value of CMX prophylaxis has also been demonstrated in Africa, where CD4+ cell counts are rarely available. We therefore developed a simple score predictive of a threshold CD4+ cell count (400/mm3) below which CMX prophylaxis is indicated. In a retrospective cross-sectional study, we collected clinical and biological data on 211 HIV-infected patients recruited from January 1996 through January 1998 at Fann University Hospital in Dakar, Senegal. Several variables were identified as being predictive of a CD4+ cell count below 400/mm3 by stepwise logistic regression. Each variable was weighted according to its regression coefficient, as follows: male sex (+1), weight loss (+2), body mass index < 22 (+2), herpes zoster (+4), tuberculin induration < 5 mm (+3) and haemoglobin < or = 10 g/dL (+1). A score of > or = 4 (sum of weights) selected patients with CD4+ cell counts below 400/mm3 with a sensitivity of 98% and a negative predictive value of 83%. Such a score should be applicable in the African context and should facilitate the management of HIV-infected patients, especially the prescription of CMX prophylaxis.

[Methicillin-resistant Staphylococcus aureus in Dakar]. / Staphylococcus aureus résistants à la méticilline à Dakar.

This study was carried out at the Fann University Hospital Center in Dakar, Senegal between 1994 and 1996. The purpose was to assess the prevalence of methicillin-resistant Staphylococcus aureus and to propose alternative treatments. A total of 149 stains of Staphylococcus aureus were isolated from a variety of clinical specimens. Sensitivity to various antibiotics was tested by the disc diffusion technique (anti-biogram). Resistance to methicillin was evaluated by the oxacillin disc diffusion technique on Mueller-Hinton agar containing 5% NaCl. The prevalence of methicillin resistance was 66.4%. All strains of Staphylococcus aureus were sensitive to vancomycin. Other highly effective antibiotics included fucidic acid (94%), aminoglycosides (91%), cotrimoxazol (89.6%), and norfloxacin (84.5%). Most strains (70.6%) presented a wide profile against macrolides and related groups. The LSa phenotype (resistance to lincosamines and streptogramines) was the predominant resistant phenotype. The results of this study indicate that the prevalence of methicillin-resistant Staphylococcus aureus is increasing in Senegal. Since these strains respond well to chloramphenicol and cotrimoxazole, clinicians are advised to use these drugs as an alternative first-line treatment.

[Sensitivity profiles of enterobacteria isolated at th Fann University Hospital Center, Dakar]. / Profils de sensibilité des entérobactéries isolées au CHU de Fann, a Dakar.

This study concerns 180 strains of Enterobacteria isolated at Fann University Teaching Hospital (Dakar, Senegal). The susceptibility to antibiotics was tested by disc diffusion test (antibiogram) and by dilution method determining the minimum inhibitory concentration (MIC). All of the species present more resistant profile to beta-lactams (> 55%); however ceftriaxon and aztreonam present the lower MIC 50 (< 0.06 microgram/ml). Fluoroquinolon inhibits more than 90% of the strains of E. Coli and Proteus. Chloramphenicol is active on Salmonella, but ceftriaxon, aztreonam and the fluoroquinolon present good alternatives. Cotrimoxazole is active only on 54% of Shigella strains.

[Antifungal drug susceptibility of Candida causing oropharyngeal candidiasis in HIV infected patients]. / Sensibilité aux antifongiques des souches de Candida responsables de candidose oropharyngée chez des sujets vivant avec le VIH.

Candidiasis are very usual infections of HIV infected patients. By medicine pressure, susceptibility to antifungal drugs decrease in some Candida strains. This study carded out in 1997 at hospital, aimed to identify the yeast species isolated from HIV infected patients with oropharyngeal candidiasis, test their susceptibility to antifungal drugs and a previous antifungal treatment impact. Thus, 60 patients yielded to questionnary were recruited. Isolated yeast colonies from buccal tract after culture on Sabouraud medium with chloramphenicol were identified with the API 20 C AUX (BioMérieux) system by assimilation of different sugars. Susceptibility was evaluated by ATB FUNGUS (BioMérieux) system. 55 from the 60 isolated yeasts were identified and among them C. albicans and C. tropicalis were the main species with 75% and 11,7% respectively rates. In HIV1 infected patients, all specieswere isolated and C. albicans predominated (80,4%) on the other hand, C. albicans and C. tropicalis were the only isolated yeasts from the HIV2 infected patients with 83,3% and 16,6% respectively rates. Susceptibility of C. albicans was 72,2% to nystatine, 58,3% to amphotericin B, 83,3% to flucytosin, 12,8% to miconazole, 8,5% to econazole and 10,6% to ketoconazole. Susceptibility of C. albicans to polyenes was modified by a previous antifungal treatment. This study indicated emergence of saprophytic yeasts of the buccal mucosa and seemed to be more fostered by HIV1 serotype than HIV2. So, C. albicans's susceptibility to polyenes decreased by untimely use of antifungal drugs and by controlling it one could improve the clinic conditions of HIV infected patients.

[Sensitivity to cotrimoxazole of bacteria isolated at the Central University Hospital of Fann, Dakar]. / Sensibilité au cotrimoxazole des bactéries isolées au CHU de Fann-Dakar.

This study concern a survey of bacterial resistance to cotrimoxazole; 510 strains of Enterobacteria (167), Vibrio cholerae(206) and Staphylococcus aureus(137) were tested by disc diffusion and agar dilution methods. An interview was conducted with 86 health personals to appreciate the influence of prescription. Staphylococcus aureus were the most susceptible bacteria (13% of resistance), and Vibrio cholerae the most resistant (95%). Related to the gender, Enterobacteria present 43 to 72% of resistance. The data of interview show a very frequent use of cotrimoxazole, related to the disponibility and the accessibility of this drug.

[Pneumocystosis in HIV infected patients presenting with acid-fast bacilli negative pneumopathy at the Central University Hospital at Dakar]. / La pneumocystose chez les sujets infectés par le VIH presentant une pneumopathie à BAAR négative au CHU de Fann à Dakar.

Pneumocystosis is an opportunist parasitic disease which occurs currently at Europe and United States in HIV infected patients. In Africa, the disease is not current. Pneumocystosis has been detected in the Fann medical universitary center at Dakar from HIV infected patients with acido alcoholo resistant bacilli negative pneumopathy. Analysis of broncho alveolar liquid(BAL) of 29 patients after Giemsa and Blue of Toluidin O staining allowed isolating of two cases of pneumocystosis. A man and a woman were the patients. They were HIV1 positive with at X ray bilateral interstitial syndrome. The CD4 lymphocytes count of the one was lower than 200/mm3 and for the other it was higher than 200/mm3.