At the XV International AIDS Conference in Bangkok
last week, the
Bill & Melinda Gates Foundation announced a $44.7
million grant to support CREATE — the
Consortium to Respond
Effectively to the AIDS-TB Epidemic — which will
conduct research on urgently needed strategies to control
tuberculosis in communities with high HIV infection rates.
CREATE is led by the
Johns Hopkins Center
for Tuberculosis Research and includes researchers and
health policy experts in Africa, South America, Europe and
the United States.
TB is now the leading killer worldwide of people with
HIV. Because of their weakened immune systems, people with
HIV are especially vulnerable to TB, and TB rates have
increased significantly in countries with high HIV
prevalence. In sub-Saharan Africa, two-thirds of TB
patients are co-infected with HIV, and of the estimated 1.6
million deaths caused by TB annually, one quarter occur
among people living with HIV/AIDS.
"We cannot successfully fight HIV/AIDS without also
fighting TB, which has emerged as the leading killer of
HIV-positive people," said Helene Gayle, director of the
HIV, TB and Reproductive Health program at the Gates
Foundation. "We've seen a devastating resurgence of TB in
developing countries hit hard by HIV/AIDS, and to control
it, it is essential that creative new strategies like those
CREATE is pursuing are identified and quickly put into
practice."
Richard Chaisson, professor of medicine at Johns
Hopkins, is principal investigator of CREATE.
"TB and HIV form a lethal combination, each amplifying
the other's progress," Chaisson said. "By studying the
impact of promising new strategies, we hope to inform
critical health policy decisions in countries confronting
TB and HIV."
The current strategy for managing TB in developing
countries is called directly observed therapy short course,
or DOTS. It can help ensure high TB cure rates, but its
reach is limited because DOTS relies on patients to seek
treatment themselves and targets only those with active TB,
not those with latent infection. In communities with high
HIV rates, TB rates have risen dramatically even where DOTS
is available.
The grant announced July 15 will support research on
two potential interventions: improved case finding and
isoniazid preventive therapy, or IPT. CREATE researchers
will determine the cost-effectiveness and feasibility of
these interventions in communities hard hit by TB-HIV
co-infection.
The improved case finding intervention relies on
community-based education and expanded TB diagnosis
programs to identify people with active TB who would
otherwise go undiagnosed, so they can be treated before
they infect others.
IPT employs the antibiotic isoniazid to prevent those
who are infected with latent TB from developing the active
form of the disease. Previous research has shown that IPT
can be more than 85 percent effective in reducing an
individual's risk of developing active TB, but the impact
of widespread IPT usage on an ongoing TB epidemic has not
been determined.
CREATE will use the grant to conduct over seven years
three large-scale community studies in Africa and South
America.
In Zambia and South Africa, a
study will evaluate the impact of a targeted package of IPT
and improved case finding. The study will conduct school-
and community-based TB education campaigns to help people
recognize active TB cases and will intensify existing TB
diagnosis programs. Also, researchers will determine the
benefits of providing IPT to all members of a household
where a TB patient lives, to prevent further transmission
of the disease.
In South Africa, researchers will
examine the impact of IPT on TB among gold miners, a
population with a latent TB infection rate of more than 90
percent and high rates of HIV infection and a respiratory
disease called silicosis, two of the strongest risk factors
for progression to active TB. Preliminary data and
mathematical modeling suggest that providing communitywide
IPT for both HIV-positive and HIV-negative miners may
dramatically reduce TB disease rates.
In Brazil, a study will deliver
IPT to HIV-positive patients in Rio de Janeiro who are
co-infected with TB and have access to antiretroviral
therapy through Brazil's national HIV treatment program.
Researchers have found that widespread use of ARV treatment
in Rio de Janeiro led to a decline in TB/HIV deaths but had
no impact on overall active TB rates. This study will
determine if adding IPT to existing ARV treatment will
reduce active TB rates, which would help slow the spread of
TB.
Throughout the course of the studies, CREATE's policy
and advocacy team, which includes representatives from the
World Health Organization and the Stop TB Partnership, will
work to ensure that research findings are quickly
disseminated to public health officials and translated into
new, more effective TB control strategies.
Gayle, of the Gates Foundation, emphasized that while
CREATE's research could lead to important progress on
controlling the joint epidemics, additional resources and
increased collaboration among the TB and HIV communities
are urgently needed to support further research and expand
access to appropriate interventions.
"Anyone who is concerned about HIV/AIDS must also be
concerned about TB, because the two diseases go hand in
hand," Gayle said. "I'm optimistic that researchers,
policy-makers and funders around the world will recognize
the need to alleviate the tremendous burden of these linked
epidemics."
Institutions participating in CREATE include the Johns
Hopkins University Center for Tuberculosis Research, the
London School of Hygiene and Tropical Medicine, Aurum
Health Research in South Africa, the University of Zambia,
South Africa's Stellenbosch University, the Municipal
Health Secretariat of Rio de Janeiro, WHO and the U.S.
Centers for Disease Control and Prevention.
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