New IDSA guidelines on diagnosis of TB in adults and children A task force supported by the American Thoracic Society (ATS), Centers for Disease Control and Prevention (CDC) and Infectious Diseases Society of America (IDSA) has published new guidelines on the diagnosis of tuberculosis (TB) and latent tuberculosis infection (LTBI) in adults and children. The guidelines published in the January 2017 issue of the Clinical Infectious Diseases journal include 23 evidence-based recommendations about diagnostic testing for latent tuberculosis infection, pulmonary TB and extrapulmonary TB. The six strong recommendations include: • An interferon-γ release assay (IGRA) rather than a tuberculin skin test (TST) should be done in individuals 5 years or older who are likely to be infected with Mtb, who have a low or intermediate risk of disease progression, and in whom it has been decided that testing for LTBI is warranted. • Acid-fast bacilli (AFB) smear microscopy is recommended in all patients suspected of having pulmonary TB. • Rapid molecular drug susceptibility testing for rifampin with or without isoniazid is recommended using the respiratory specimens of persons who are either AFB smear positive or Hologic Amplified MTD positive and who meet one of the following criteria: (1) have been treated for tuberculosis in the past (2) were born in or have lived for at least 1 year in a foreign country with at least a moderate tuberculosis incidence (≥20 per 100 000) or a high primary multidrug-resistant tuberculosis prevalence (≥2%) (3) are contacts of patients with multidrug-resistant tuberculosis, or (4) are HIV infected. • Mycobacterial cultures should be done on specimens collected from sites of suspected extrapulmonary TB. • Genotyping should be done on one culture isolate from each mycobacterial culture-positive patient.