title: Symptom-based screening tool in ruling out active tuberculosis among HIV-infected patients eligible for isoniazid preventive therapy in Tanzania.
abstract: OBJECTIVE
  We assessed the usefulness of the National TB and Leprosy Control Program (NTLP) symptom-based tuberculosis (TB) screening tool in identifying HIV-infected patients eligible for isoniazid preventive therapy in Muhimbili National Hospital, Dar es Salaam Tanzania.
  
  
  METHODS
  Descriptive cross-sectional study. Data collected included socio-demographic and clinical data. Chest X-ray, sputum for acid-fast bacilli (AFB) microscopy, mycobacterial culture, CD4 + count and complete blood count were performed. Patients were considered not having active TB if they presented with no symptom in the screening tool, which comprised these symptoms: cough, fever and excessive night sweats for ≥2 weeks; weight loss of ≥3 kg in 4 weeks and haemoptysis of any duration. The reference standard was a negative culture for Mycobacterium tuberculosis.
  
  
  RESULTS
  We enroled 373 patients, of whom 72.1% were females. Active pulmonary TB was found in 4.1% (14/338) of the participants as defined by a positive culture. The sensitivity and specificity of the NTLP screening tool were 71.4% (10/14) and 75.9% (246/324), respectively. False-negative rate was 28.6% (4/10). Cough, fever for ≥2 weeks and weight loss were independent predictors of NTLP-defined TB. Cough ≥2 weeks predicted TB when a positive culture was used to define TB.
  
  
  CONCLUSIONS
  The screening tool had fairly good sensitivity and specificity for TB screening; however, there is a possibility that about 29% of the screened population will be given IPT while they are supposed to receive a full course of TB treatment.
authors.affiliation: Department of Internal Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
authors.forename: Grace A
authors.initials: GA
authors.lastname: Shayo
authors.affiliation: Department of Internal Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
authors.forename: Lilian T
authors.initials: LT
authors.lastname: Minja
authors.affiliation: National Tuberculosis and Leprosy Program of the Ministry of Health and Social Welfare of Tanzania, Dar es Salaam, Tanzania.
authors.forename: Said
authors.initials: S
authors.lastname: Egwaga
authors.affiliation: Department of Internal Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Bakari
authors.affiliation: Department of Internal Medicine, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania.
authors.forename: Ferdinand M
authors.initials: FM
authors.lastname: Mugusi
keywords: NTLP screening tool; Sensibilidad; especificidad; herramienta de cribado del PNTL; negative predictive value; outil de dépistage PNLTL; prueba cutánea de la tuberculina; sensibilité; sensitivity; specificity; spécificité; test cutané tuberculinique; tuberculin skin test; valeur prédictive négative; valor predictivo negativo