Screening for TB in people living with HIV

In 2011 8.7 million people were diagnosed with tuberculosis (TB) and 1.4 million people died, despite the fact the disease is curable and preventable.

TB is particularly prevalent among people with HIV and in 2013 the World Health Organization estimated that TB was responsible for a quarter of all HIV-related deaths.

But thanks international screening and TB-HIV programmes 500,000 more people with TB and HIV are alive today.  And School research has been one of the key drivers of this success.

A research team led by professor of international health, Peter Godfrey-Faussett and senior lecturer Helen Ayles, launched the ProTEST initiative (1999-2004) in Zambia, Malawi and South Africa, which found that providing collaborative TB/HIV care in poor settings was relatively inexpensive. This has had a direct impact on WHO guidelines, first published in 2004 and updated in 2012, promoting the integration of TB and HIV services.

Researchers also built on previous studies conducted by Godfrey-Faussett, which found that HIV-related TB was due to ongoing transmission rather than reactivation. New findings showed that for people with HIV, recurrent TB was more likely to be the result of reinfection.

The School’s population-based HIV and TB disease surveys found large numbers of undiagnosed TB cases, highlighting the failure of the global TB control strategy, DOTS, to reduce the number of TB cases related to HIV. The researchers concluded that new approaches to tackling TB were needed.

School researchers ran two large-scale community randomised trials: Professor Liz Corbett ran DetecTB in Zimbabwe from 2006 to 2009 and Ayles and Godfrey-Faussett ran ZAMSTAR, in Zambia and the Western Cape Province in South Africa from 2006 to 2010. DetecTB showed that active case-finding, using a mobile van, could have rapid effects on TB transmission.

In the ZAMSTAR study community-level enhanced TB case-finding and household level TB-HIV care were implemented. These findings were heavily cited in Tuberculosis Prevalence Surveys: A Handbook, published by WHO in 2011 for TB experts, survey investigators, researchers and advisors. Ayles, , who conducted the population-based studies, was the lead author of one of the chapters.

The book also promotes the use of surveys, modelled on the School’s population surveys, as a way of measuring TB control throughout the world.

In 2010-11 the School’s researchers undertook meta-analyses of data from their African population surveys, in collaboration with WHO and the US Centers for Disease Control and Prevention and developed a simplified symptom-based screening algorithm for people who are less likely to have active TB and therefore are eligible for preventive therapy.

Ayles, Corbett and Godfrey-Faussett were also instrumental in updating WHO’s policy around collaborative TB/HIV work in 2012 and the DetecTB survey was referenced with regard to joint planning of services.