The Challenge of Latent TB Infection

False-Positive Tuberculin Skin Test Results Among Low-Risk Healthcare Workers Following Implementation of Fifty-Dose Vials of Purified Protein Derivative

“…However, as infection control procedures in the United States have improved 8 and the incidence of TB in the United States has declined, 9 serial TB screening programs targeting low-risk HCWs have increasingly become a source of false-positive test results. 3 Annual screening for low-risk HCWs prevents active TB disease at an incremental cost of more than US$1.5 million per case prevented compared to testing only those with known TB exposure. 10 Here, we demonstrate that false-positive TST conversions can result in expenditures of hospital resources beyond the cost of a low-yield LTBI testing and treatment program.…”

“…10 Here, we demonstrate that false-positive TST conversions can result in expenditures of hospital resources beyond the cost of a low-yield LTBI testing and treatment program. 3 An increase in false-positive results occuring over a short period of time in a population with a very low baseline rate of test conversions can give the appearance of institutional TB transmission, leading to unnecessary investigations by hospital epidemiology and infection control personnel.…”

“…1 However, little evidence suggests that current work at a US healthcare facility alone increases the risk of infection with Mycobacterium tuberculosis . 2,3 Testing low-risk individuals for latent TB infection (LTBI) increases the risk of false-positive results and is not recommended by diagnostic guidelines jointly issued by the American Thoracic Society (ATS), Centers for Disease Control and Prevention (CDC), and Infectious Diseases Society of America (IDSA). 4 Here, we report a significant increase in presumed false-positive tuberculin skin test (TST) conversions among healthcare workers (HCWs) associated with changing from a 10-dose to a 50-dose vial of purified protein derivative (PPD).…”

Redox‐guided small molecule antimycobacterials

“…Infections by the highly successful pathogen Mycobacterium tuberculosis (Mtb) have been effectively treated by combination chemotherapy for the past several decades . While the recommended regimen of drugs is highly effective in curing tuberculosis (TB), the emergence of drug resistance and latent TB are major developments that are roadblocks in preventing the eradication of this disease . The frontline TB drugs have well established mechanisms and the search is on for new drugs with novel mechanisms that the pathogen is unable to overcome.…”

Boosting with recombinant MVA expressing M. tuberculosis α-crystallin antigen augments the protection imparted by BCG against tuberculosis in guinea pigs

“…TB is one of the leading causes of death claiming a loss of 1.8 million human lives globally as reported by WHO in 2015 1 . One third of the world’s population is infected latently with M. tuberculosis and is potentially at the risk of developing an active disease 1 , 2 . The only preventive measure available is Mycobacterium bovis Bacillus Calmette-Guerin (BCG), which has fared extremely well in providing protection against childhood TB 3 .…”