AnthonyHarries of the International Union against Tuberculosis and Lung Disease, United Kingdom, talks with Judith Currier of UCLA at the XIX International AIDS Conference (AIDS 2012) in Washington, D.C. © IAS/Ryan Rayburn – Commercialimage.net

A report from Gabriel Chamie, MD, MPH, UCSF assistant professor of medicine, Division of HIV/AIDS, San Francisco General Hospital and Trauma Center:

At Friday morning’s plenary session, Dr. Anthony Harries delivered an outstanding overview of tuberculosis (TB)/HIV co-infection, summarizing recent updates and unresolved issues in TB prevention, diagnosis and treatment.

TB is the leading cause of death in HIV-infected persons worldwide, and the incidence of TB remains unacceptably high in settings with generalized HIV epidemics.

Fortunately, as Dr. Harries summarized succinctly, we now have the tools, based on good evidence, to tackle HIV-associated TB, including the “3 Is”, isoniazid preventive therapy (IPT), intensified TB case-finding (ICF), infection control, and antiretroviral therapy. Antiretroviral therapy (ART) clearly prevents active TB disease and the importance of starting ART early during TB treatment is now well established. IPT for prevention of active TB disease is effective, synergistic with ART in its protective effects, and a part of WHO international guidelines.

Unfortunately, IPT scale-up has been extremely slow and a lack of integrated HIV/TB service delivery results in too few HIV-associated TB cases receiving timely ART. Implementation research to address these gaps is needed.

Finding, diagnosing and treating TB (intensified case finding) is critical for reducing TB associated mortality and TB transmission.

[World Health Organization] guidelines for simple symptom screening for TB in HIV-infected persons provide guidance to “rule-out” TB, but numerous challenges remain. The symptom screen has a high negative predictive value, but the symptoms are non-specific and common, and TB diagnosis remains a major obstacle. Dr. Harries emphasized that the usual ways of diagnosing TB (sputum smear and chest x-ray) in much of the world are time consuming, costly and insensitive.

Recent TB diagnostics, including the Xpert MTB/RIF assay and a point-of-care urine LAM assay, are major breakthroughs. However questions remain: how far can we decentralize these diagnostics? How far can we reduce the costs through broader implementation?

Dr. Harries closed with a call to action, saying, “We must implement what we know works,” and we must “use the full weight of our collective conscience to tackle the poverty that is at the root of this HIV/TB epidemic.”

A detailed review of the issues he covered in this plenary will be published in the Journal of the International AIDS Society.