title: Risk factors for negative sputum acid-fast bacilli smears in pulmonary tuberculosis: results from Dakar, Senegal, a city with low HIV seroprevalence.
abstract: METHODS
  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.
  
  
  METHODS
  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.
authors: INSERM U13/IMEA, Paris, France. b.samb@st-maurice.inserm.fr
authors: B
authors: B
authors: Samb
authors: P S
authors: PS
authors: Sow
authors: S
authors: S
authors: Kony
authors: M
authors: M
authors: Maynart-Badiane
authors: G
authors: G
authors: Diouf
authors: S
authors: S
authors: Cissokho
authors: D
authors: D
authors: Bâ
authors: M
authors: M
authors: Sané
authors: F
authors: F
authors: Klotz
authors: M A
authors: MA
authors: Faye-Niang
authors: S
authors: S
authors: Mboup
authors: I
authors: I
authors: Ndoye
authors: E
authors: E
authors: Delaporte
authors: A A
authors: AA
authors: Hane
authors: A
authors: A
authors: Samb
authors: J P
authors: JP
authors: Coulaud
authors: A M
authors: AM
authors: Coll-Seck
authors: B
authors: B
authors: Larouzé
authors: J F
authors: JF
authors: Murray
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000188:drug therapy / Q000382:microbiology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006784:Hospitals, Teaching; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D011446:Prospective Studies; D012307:Risk Factors; D012675:Senegal / Q000453:epidemiology; D013183:Sputum / Q000382:microbiology; D014391:Tuberculosis, Miliary / Q000453:epidemiology; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy / Q000382:microbiology*