/ 7 June 2007

Dual TB, HIV treatment key to Aids battle

African, especially Southern African, nations must link tuberculosis (TB) testing and treatment with HIV-prevention programmes if they are to win the Aids battle, a top World Health Organisation (WHO) official said on Thursday.

Dr Kevin de Cock, head of WHO’s HIV/Aids department, told the Third South African Aids Conference that traditional treatments for Africa’s rampant TB problem could worsen the Aids pandemic and fuel the spread of the potentially fatal lung infection.

”TB programmes alone cannot reverse the tide,” De Cock told about 4 000 Aids researchers, activists and healthcare officials at the conference in Durban.

He said it was vital to offer those infected with HIV and TB convenient and effective treatment for both diseases.

TB, which is spread through close personal contact, has long been a problem in Africa, where hundreds of millions are latent carriers of the disease. But the growing relationship between TB and HIV has made treatment of both diseases more difficult in vulnerable populations.

The emergence of extremely drug-resistant TB (XDR-TB), a strain virtually immune to traditional and modern antibiotics, has raised alarm bells since recently surfacing in South Africa’s KwaZulu-Natal province and neighbouring Lesotho, where it killed up to 85% of those infected, the majority of whom also had HIV.

The strain has since spread to other parts of Africa as well as to the industrialised world, including the United States. The US government recently took the rare step of quarantining a man who had become infected with XDR-TB.

Two diseases interlinked

The prospect of a new and more virulent TB pandemic sweeping through sub-Saharan Africa is a far more serious threat because the two diseases are so prevalent and interlinked in the region.

In South Africa, 61% of the roughly 250 000 people diagnosed with TB each year have HIV.

HIV-positive people and others with weakened immune systems are particularly vulnerable to TB as well as other opportunistic infections. But XDR-TB has led to not only higher mortality rates, but also much faster deaths in HIV-positive populations.

In turn, HIV helps to spread TB in the general population. One of the paradoxes of the HIV pandemic is that the antiretroviral drugs that have saved so many lives contribute to a jump in TB because those who are co-infected are not being treated simultaneously for both diseases.

”HIV has caused a devastating reversal in our ability to treat TB,” Robin Wood, director of South Africa’s Desmond Tutu HIV Centre, said in a presentation to a Roche Diagnostics symposium on the sidelines of the conference. Wood said the solution was to combine treatments.

Doing so will require a huge investment in TB laboratories and related medical infrastructure in much of Africa as well as better tools to tackle the disease.

TB is still diagnosed using methods, such as skin tests, that can take days or even weeks to complete, while treatment can extend to months or sometimes more than a year, a challenge for Africa’s often highly mobile population.

A urine-based dipstick test under development that gives results almost instantly could be the answer to beginning to tackle TB. ”That would be a great asset if we could get it,” Wood said. — Reuters