What Is the Lam ELISA TB Test
The Lam ELISA TB test is a lateral flow immunoassay that detects lipoarabinomannan, a major glycolipid antigen from the cell wall of Mycobacterium tuberculosis, in urine or other clinical specimens. It provides a rapid result, often within 25 minutes, without requiring complex laboratory infrastructure, making it suitable for point-of-care settings in high-burden regions. The test is designed to support clinicians in identifying active tuberculosis cases faster than traditional sputum smear microscopy, particularly when molecular or culture methods are unavailable or delayed.
Unlike nucleic acid amplification tests, the Lam ELISA TB test does not require DNA extraction or thermal cycling, which reduces both equipment costs and the need for highly trained technicians. It targets a carbohydrate antigen rather than a genetic target, so it can sometimes detect cases where PCR yields indeterminate results. The test format uses a simple strip or cassette with a conjugate pad, membrane, and absorbent pad, and the result is read visually or with a small reader device to semi-quantify the signal intensity.
Clinical Performance and Use Cases
In meta-analyses of adults with suspected tuberculosis, the Lam ELISA TB test has shown a pooled sensitivity of roughly 40 to 50 percent and a specificity above 95 percent, with higher sensitivity in patients who have advanced immunosuppression, such as those with low CD4 counts. It is particularly recommended by the World Health Organization for use in HIV-positive individuals with signs of tuberculosis, where rapid diagnosis can reduce mortality and enable earlier isolation and treatment decisions.
The test has been deployed in emergency departments, outpatient clinics, and mobile health units across sub-Saharan Africa and parts of Asia, often alongside symptom screening and chest radiography. Studies have shown that using the Lam ELISA TB test can shorten the time to treatment initiation by several days compared with waiting for culture results, which can take weeks. It is also used in some settings to monitor treatment response, although serial measurements must be interpreted carefully alongside clinical findings and imaging.
Regulatory Status, Manufacturing, and Market
The Lam ELISA TB test has received prequalification from the World Health Organization and regulatory clearance in multiple countries, with the manufacturer publishing performance data and quality control protocols to support large-scale procurement by global health agencies. The test is produced under ISO 13485-certified conditions, and lot-to-lot consistency is monitored through external quality assessment programs coordinated by organizations such as the Foundation for Innovative New Diagnostics.
Major buyers include national tuberculosis programs, the Global Fund to Fight AIDS, Tuberculosis and Malaria, and United Nations procurement agencies, which negotiate pricing and distribution through centralized tenders. The test competes with other rapid tuberculosis diagnostics, including molecular point-of-care platforms from companies like Abbott and Cepheid, as well as traditional culture systems from Becton Dickinson and bioMérieux. In 2023, the market for rapid tuberculosis diagnostics was estimated at several hundred million dollars annually, with lateral flow assays representing a growing share due to their low cost and ease of use. For detailed regulatory and procurement information, see the World Health Organization prequalification page at who-prequalified in vitro diagnostics and for market data, the FIND diagnostic pipeline at finddx.org tuberculosis diagnostics.