Casting a wider net for tuberculosis cases

Extract In 1882, Robert Koch was the first to stain tubercle bacilli, the causative micro-organisms for tuberculosis (TB). His culture method using inspissated blood-serum was later improved by Loewenstein and Jensen using eggs to enrich the culture medium, followed by Middlebrook introducing a medium containing agar. It took several weeks, and sometimes months, to yield a positive TB result. To hasten the laboratory diagnosis, Middlebrook developed a 14C-labelled medium and with Johnston Laboratories constructed the BACTEC 460TB instrument [1]. The radiometric broth medium was succeeded by non-radiometric stand-alone culture and detection systems offered by several companies. More recently, molecular testing platforms such as the Cepheid GeneXpert MTB/RIF Ultra, which rapidly detects Mycobacterium tuberculosis DNA in patient samples by nucleic acid amplification testing (NAAT), have enabled same-day microbiological diagnosis of TB.