In the course of our work on TB diagnostics in Peru the ubiquitous problem of how to deliver adequate TB control in prisons presented a significant challenge. Though it was clear that enhanced laboratory capacity was needed for the prison service it was equally clear that construction, staffing and maintenance of an on-site TB laboratory in every prison was neither desirable, practical or necessary.

In 2004 we decided that one approach to this problem would be to deliver enhanced laboratory capacity on a periodic basis - enabling intermittent campaigns of intensive active case finding in a rolling cycle - and that the vehicle (pun intended) for this could be a portable TB laboratory which moved from prison to prison each month.

Our group developed the non-commercial MODS assay (www.modsperu.org) which delivers low-cost, rapid, liquid culture TB detection and concurrent rifampicin and isoniazid resistance testing (in 7 days for less than $3.50).

Because this methodology is a direct drug susceptibility test that does not involve manipulation of positive cultures (all the test resuts can be read from the original culture without the need for subculture) it requires only small volume incubator capacity and biosafety level 2 facilities - ideal ingredients for a laboratory in a converted 20' shipping container.