Africa is worst hit by dual epidemic
The realization that it will be impossible to curb the spread of HIV/AIDS without tackling tuberculosis (TB) and vice versa has led to an upsurge in joint research, surveillance and treatment initiatives into the two diseases that are feeding off each other to devastating effect.
One-third of the estimated 40 million people living with HIV/AIDS are also infected with TB. In sub-Saharan Africa, the proportion is even higher. People infected with HIV are five to 10 times more likely to develop TB in a given year than those who are not, fuelling an upsurge in the TB epidemic which kills an estimated two million people worldwide a year.
“There were countries in Africa in the most horrendous situations of poverty and war, and yet TB rates were going down,” according to Dr Bernard Fourie, honourary scientist with South Africa’s Medical Research Council and former head of its TB research programme. “But since the late 1980s not one single country in sub-Saharan Africa has seen a decline.”
“This is undoubtedly because of HIV,” said Fourie, who worked in TB research for 30 years.
Africa is the worst hit region in terms of the impact of TB/HIV. In 2003, TB incidence fell in five of six WHO regions but increased dramati¬cally in many African countries. South Africa is one of the hardest hit nations.
The South African Medical Research Council forecasts that there will be 300 000 cases of TB this year and 30 000 deaths from it in the country — a fatality rate of 10% compared to one of 3–5% before the advent of HIV/AIDS. WHO said South Africa had 558 estimated cases of TB per 100 000 population in 2002, second only to Zimbabwe.
WHO’s ‘3 by 5’ Progress Report published in January estimated that between 37 000 and 62 000 people out of the 837 000 South Africans needing antiretroviral medicines (ARVs) were actually receiving the treatment at the end of December — a coverage rate of 7%.
The problems faced by high burden countries such as South Africa have spurred the drive to tackle the dual epidemic with a coordinated response intended to draw on the strengths of the TB control strategy, DOTS, and the dynamism of the ‘3 by 5’ drive to get three million people with HIV/AIDS on antiretroviral treatment by the end of 2005.
Last September WHO launched a new internal HIV/TB Task Force to boost coordination between countries and encourage TB services and HIV/AIDS programmes to work more closely together.
The Task Force was launched at the annual conference of the TB/HIV Working Group of the Global Stop TB Partnership, which was held in Addis Ababa in September last year.
The conference, grouping 40 countries and agencies, concluded that more needed to be done to implement WHO’s Policy on Collaborative TB/HIV Activities. (See box on p. 166.) They agreed on the urgent need for more drugs, newer testing methods and more information on how best to treat TB/HIV dual infection and concluded that the DOTS treatment strategy for TB was essential, but not sufficient by itself.
“The top priority is strengthening of DOTS, but it is necessary to implement and scale up additional existing interventions to prevent TB, such as chemoprophylaxis, and to diagnose TB more effectively by carrying out intensified case finding,” Dr Mario Raviglione, Director of WHO’s Stop TB Department told the Bulletin.
“The control of HIV is key for TB control as well. Thus, any measure should be attempted to prevent HIV infection and to treat it,” Raviglione said.
The meeting report called for better diagnostic tools to replace the smear microscopy test which was developed a century ago and is often too imprecise to detect TB in HIV-positive patients who show atypical symptoms.