Scaling up laboratory capacity for the coming storm of XDR-TB, and why the HIV treating community must get involved now

By Theo Smart

“Can someone give me a good reason why all TB suspects should not have access to drug susceptibility testing (DST)? I want a good reason to stop me from doing what we think we ought to do,” Dr Ken Castro, Director of the Division of Tuberculosis Elimination at the Centers for Disease Control and Prevention (CDC) told an audience at the 37th Union World Conference on Lung Health, held from October 31st to November 4th in Paris.

Over the course of the conference, Dr Castro argued passionately for an emergency scale-up of laboratories in resource-limited settings in order to respond to the threat of extensively drug resistant TB — which could cause the death of millions of people with HIV in Africa (and possibly the world) and undermine the recent progress in tackling HIV/AIDS (see more below).

“There is an urgent need for enlarged budget plan for lab capacity — buildings, hardware, software and all the components,” Dr Castro said.

The stance won him praise from treatment activists like Mark Harrington of the Treatment Activist Group. “[Dr Castro]’s turned into the biggest proponent of universal access to culture and DST and universal treatment for all,” said Harrington. In fact, when he sensed a less than enthusiastic response to Dr Castro’s appeal from TB community in the audience, Harrington urged them all to become “activists like Ken Castro.”

But if the response from other TB experts at the meeting had seemed muted, it wasn’t because they disagreed with the call for universal access to improved diagnostics — it was because they know that introducing the laboratory capacity to do mycobacterial culturing and DST (or possibly even the new emerging TB diagnostic technologies) into resource constrained settings will truly be a daunting challenge.

“Setting up culture facilities requires a particular investment of resources and expertise, and [Medecins sans Frontieres’] field experience has shown that this is often more complicated and difficult to realize in the field than is widely appreciated,” says a just released MSF report on the current TB diagnostic pipeline (which can be downloaded at http://www.accessmed-msf.org/documents/Diagnostics%20Pipeline%20Report.pdf).

“It’s been said over and over that laboratory services really represents the weak link in the chain of TB control. This weakness is now accentuated within the context of XDR-TB,” said Dr Karin Weyer, the Director of Unit for Tuberculosis Operational and Policy Research at the South African Medical Research Council (MRC), and who is also with the WHO/International Union Against Tuberculosis and Lung Disease’s (IUATLD) Supranational Reference Laboratory in South Africa.

Dr Weyer presented an overview at the conference on the challenges involved in scaling up laboratory networks, what will be needed for DST and an overview of rapid diagnostics that are currently in the pipeline.