/ 2 November 2007

Deadly TB, HIV merge into co-epidemic

Drug-resistant tuberculosis (TB) and HIV have merged into a double-barrelled pandemic that is sweeping across sub-Saharan Africa and threatening global efforts to eradicate both diseases, according to a report released on Friday.

Overburdened health systems are unable to cope with the pandemic and risk collapse, says the report, which calls for urgent measures to curb its spread.

One-third of the world’s 40-million people living with HIV/Aids also have TB, and the death rate for people infected with both is five times higher than that for TB alone.

The situation is aggravated by surging rates of multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB precisely in those areas where the rates of HIV infection are highest.

MDR-TB and XDR-TB are resistant to some or all of the standard drugs used to fight the disease.

“Now the eye of the storm is in sub-Saharan Africa, where half of new TB cases are HIV co-infected,” says Veronica Miller, co-author of the report and director of the Forum for Collaborative HIV Research, which issued the study.

“Unlike bird flu, the global threat of HIV/TB is not hypothetical — it is here now,” she said.

One-third of the world’s population carries the TB bacterium, but the disease remains latent in nine out of 10. HIV, however, changes the equation: of those whose immune systems have been compromised by HIV, 10% will develop active TB each year, according to the report.

“In today’s world, a new TB infection occurs every second. When one considers that much of this transmission occurs in areas with high HIV prevalence, the imminent danger of a global co-epidemic is clear,” says Diane Havlir, head of the World Health Organisation’s (WHO) working group on TB/HIV.

TB control has been severely destabilised in regions with high rates of HIV, the study says.

In one community of 13 000 people outside Cape Town, South Africa, the TB patient case load increased six-fold between 1996 and 2004, the researchers report.

“There has been a staggering increase in TB in this community, and this has been replicated right across Southern Africa,” Stephan Lawn, a medical researcher at the University of Cape Town, said in a statement.

The report calls for urgent coordinated action on the part of governments, researchers, drug companies and local communities.

The measures called for include fast diagnostic tests to detect all forms of TB in HIV-infected adults and children; new methods to map HIV and TB hot spots rapidly; new screening tools to identify new cases of drug-resistant TB; and better equipment for field laboratories in the most affected areas.

There are approximately nine million new cases of TB in the world every year, according to the WHO. In 2005, the disease killed 1,6-million people.

At the same time, an estimated 40-million people are living with HIV, according to the United Nations and WHO. There were 4,3-million new infections in 2006 with 2,8-million (65%) of these occurring in sub-Saharan Africa.

In 2006, 2,9-million people died of Aids-related illnesses.

In South Africa, HIV/Aids is the leading cause of child mortality and accounts for 40% to 60% of all deaths nationwide, according to the UN Children’s Fund. — AFP