Date Published: July 12, 2011
Publisher: Public Library of Science
Author(s): Luis Eduardo Cuevas, Mohammed Ahmed Yassin, Najla Al-Sonboli, Lovett Lawson, Isabel Arbide, Nasher Al-Aghbari, Jeevan Bahadur Sherchand, Amin Al-Absi, Emmanuel Nnamdi Emenyonu, Yared Merid, Mosis Ifenyi Okobi, Juliana Olubunmi Onuoha, Melkamsew Aschalew, Abraham Aseffa, Greg Harper, Rachel Mary Anderson de Cuevas, Kristin Kremer, Dick van Soolingen, Carl-Michael Nathanson, Jean Joly, Brian Faragher, Stephen Bertel Squire, Andrew Ramsay, Megan Murray
Abstract: Luis Cuevas and colleagues report findings from a multicenter diagnostic clinical trial in tuberculosis, showing that the sensitivity and specificity of a “front-loaded” diagnostic scheme is not inferior to that of a standard diagnostic scheme.
Partial Text: Nine million people developed tuberculosis (TB) and 1.7 million died from the disease in 2008 , with over 90% of cases occurring in low- and middle-income countries (LMICs) . Most patients in LMICs are investigated by direct sputum smear microscopy, which, although widely available, has low sensitivity  and requires the examination of multiple specimens over several days to maximise the identification of cases ,. Most national TB programmes (NTPs) collect specimens using a spot-morning-spot (SMS) scheme, whereby patients provide one “on the spot” specimen at the time of consultation, one specimen produced at home the morning of the following day, and a third specimen on the spot when the patient brings the morning specimen to the service. This scheme became widely adopted after a study by Andrews and colleagues in the 1950s concluded that this combination identified the highest number of patients with the lowest number of visits . Since the scheme requires at least two visits, however, patients often abandon the diagnostic process –.
TB is a disease of poverty and a global public health emergency . Patients with chronic cough are the main source of infection, and their early identification and treatment are key to effective control . Simple diagnostics suitable for community-based health services would significantly improve TB control activities but unfortunately are not expected to be available in the near future . Smear microscopy thus remains the test most widely used for diagnosis in LMICs.