The most bizarre infectious disease story of recent weeks must be this from the Boston Globe. Diagnosis is a key issue in tuberculosis control and all potential new techniques deserve our consideration but this one certainly comes as a surprise.

Bart Weetjens of the Pest Management Centre, Sokoine University of Agriculture, Tanzania has pioneered the use of giant pouched rats in the detection of landmines, for which purpose they are now deployed in Mozambique. They are credited with clearing 270 square miles of former farm and village land in southern Mozambique, allowing for the return of peasant families dislocated by the civil war of the 1980s. In what the Boston Globe calls ‘a conceptual leap’, Bart Weetjens is now using the rat’s sharp olfactory in disease detection, starting with tuberculosis.

Apparently, trained rats can evaluate saliva samples at a rate of 40 every 10 minutes. A rat signals with ‘unmistakable paw motions’ when it detects infected sputum. Scientists at Germany’s Max Planck Institute are said to be trying to determine whether the rats are detecting the scent of the actual TB bacteria or some metabolic reaction produced by the infection.

Some of the work of Weetjens and his colleagues has made it into the scientific literature (1) and one presumes that they are seeking formal peer-reviewed publication of the work they are undertaking on TB. It will be awaited with interest.

Reference

1. Machang’u RS, Mgode GF, Assenga J, Mhamphi G, Weetjens B, Cox C, Verhagen R, Sondij S, Goris MG, Hartskeerl RA (2004). FEMS Immunol Med Microbiol; 1;41(2):117-121. Serological and molecular characterization of leptospira serovar Kenya from captive African giant pouched rats (Cricetomys gambianus) from Morogoro Tanzania.