Intended for healthcare professionals

Practice Rational Testing

Diagnosing active tuberculosis in primary care

BMJ 2021; 374 doi: (Published 01 July 2021) Cite this as: BMJ 2021;374:n1590
  1. Ruvandhi R Nathavitharana, assistant professor of medicine1,
  2. Dolores Freire Jijon, assistant professor2 3,
  3. Pankaj Pal, fellow in infectious diseases1,
  4. Saurabh Rane, programme officer4 5
  1. 1Division of Infectious Diseases, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
  2. 2Universidad de Guayaquil, Guayaquil, Ecuador
  3. 3Division of Pediatric Infectious Diseases, University of Alberta, Edmonton, Canada
  4. 4Wadhani Institute for Artificial Intelligence, Mumbai, India
  5. 5Survivors Against TB, India
  1. Correspondence to RR Nathavitharana rnathavi{at}

What you need to know

  • Consider active TB disease in patients with cough, fever, night sweats, weight loss, or fatigue in settings with a high incidence of disease, or in patients without symptoms who have epidemiological risk factors such as HIV, particularly in countries with a high incidence

  • Chest radiography is a valuable screening tool to determine which patients should be referred for TB diagnostic testing

  • Testing for active TB should prioritise microbiological diagnosis with rapid, high sensitivity molecular tests, such as nucleic acid amplification assays (eg, Xpert MTB/RIF or Xpert Ultra). Mycobacterial culture remains the reference standard, but is slow to return results

  • Smear microscopy has low sensitivity and should not be relied on if nucleic acid amplification tests or culture are available

  • Refer patients to a TB specialist when concern for TB remains despite negative diagnostic test results, particularly in the absence of an alternative likely diagnosis

A 58 year old transportation worker in India with uncontrolled diabetes (HbA1c 97 mmol/mol) presents with a three month history of productive cough and decreased energy level. He has been treated empirically for community acquired pneumonia twice without improvement in symptoms.

A 24 year old student who arrived in Canada from the Philippines three years ago presents with a two month history of bilateral multiple enlargedcervical lymph nodes.

Of the 10 million people who develop active tuberculosis (TB) disease each year, approximately three million are not identified by national TB care programmes and many are undiagnosed.1 Diagnostic delays are common in both low and high resource settings2 and lead to worse individual outcomes and ongoing transmission.34 Patients often see several healthcare providers before the disease is diagnosed.56 TB most commonly presents with pulmonary involvement, but can present in a number of ways, most commonly lymphadenitis, pleural effusions, and …

View Full Text

Log in

Log in through your institution


* For online subscription