UN Chronicle | WHO Report 2005: TB Linked to HIV at Alarming Levels in Africa

WHO Report 2005
TB Linked to HIV at Alarming Levels in Africa
By Erika Reinhardt

The battle against tuberculosis (TB) is being successfully fought in most areas of the world, but in Africa the disease has reached alarming proportions with an increasing number of cases and deaths linked to HIV, said the World Health Organization in its WHO Report 2005, Global Tuberculosis Control: Surveillance, Planning, Financing, released on 24 March to coincide with World TB Day.

The WHO Report focuses on five principal indicators: incidence, prevalence, deaths, case detection and treatment success. It finds that its prevalence has declined worldwide by more than 20 per cent since 1990 and that incidence rates are falling or stable in all regions except in Africa, where TB rates have tripled since 1990 in countries with high HIV prevalence and continue to rise at 3 to 4 per cent annually.

Source: WHO Report 2005, Global Tuberculosis Control, Surveillance, Planning, Financing. The boundaries and delineations used on this map do not imply official endorsement or acceptance by the United Nations.

Case notifications from African countries show patterns that are likely to be associated with HIV infection. Women aged 15 to 24 years make up a great proportion of TB cases in countries with higher rates of HIV infection. HIV prevalence tends to be more in women than men in the same age range. The difference between the sexes is bigger in areas where HIV-infection rates are higher. The average age is typically lower for smear-positive TB cases where HIV-infection rates are higher, especially for women, a sign that younger people are more likely to be infected with HIV.

The report also states that those who are HIV-positive can easily be screened for tuberculosis and that TB patients can be offered an HIV test. This means that TB programmes can make a major contribution in identifying eligible candidates for antiretroviral (AVR) treatment. “Evidence in this report provides real optimism that TB is beatable, but it is also a clear warning”, said WHO Director-General Dr. Lee Jong-wook. “As Nelson Mandela has said, ‘we can’t fight AIDS unless we do much more to fight TB’, and it is time to match his words with urgent action in Africa on the two epidemics together.”

There has been major progress in China and India, which account for one third of the global TB burden. Both countries are leading the accelerated response to control the disease by rapidly scaling up the internationally recommended strategy for TB control (DOTS). As a result, the number of cases treated under DOTS rose 8 per cent in 2003 compared to the previous year. Other countries, including Indonesia and the Philippines, are showing similar progress. In addition, the Americas, Eastern Mediterranean, South East Asia and Western Pacific are on track to reach the United Nations Millennium Development Goal of reducing TB incidence by 2015, if strong commitment and resources are sustained.

DOTS strategy has five components: government commitment to sustained TB control; access to quality-assured TB sputum microscopy; standardized short-course chemotherapy to all cases of TB, including direct observation of treatment under proper management conditions; an uninterrupted supply of quality-assured drugs; and a standardized recording and reporting system enabling assessment of outcome in all patients.

A TB patient is carried by her two sons in Alem Kitmama, Ethiopia.
© WHO photo/P. Virot

World TB Day, celebrated annually on 24 March, is a Stop TB Partnership initiative aimed at raising awareness of the disease internationally. WHO is one of 325 members committed to controlling and ultimately eliminating tuberculosis as a public health problem. Since the Partnership’s formation in 2001, the number of people diagnosed with the disease has increased by two thirds.

According to the WHO Report 2005:

Since 1995, over 17 million people with tuberculosis have benefited from effective treatment under DOTS, but more could be achieved within countries and in research into new diagnostics, drugs and vaccines, if the annual $1-billion funding gap for TB control is filled.

By the end of 2004, about 199 of 211 countries and territories had reported case notifications for 2003 and/or treatment outcomes for patients registered in 2002; these include 99 per cent of the world’s population. WHO received reports from all 22 high-burden countries.

The 199 countries that reported in 2003 had notified 4.4 million new and relapse cases, of which 1.9 million (44%) were new sputum smear-positive and 3.7 million were from DOTS areas, including 1.8 million smear-positives. Based on surveillance and survey data, there were an estimated 8.8 million new cases of TB in 2003.

The regions of Africa (27%), South East Asia (35%) and Western Pacific (22%) together accounted for over 80 per cent of all notified cases and similar proportions of new smear-positive cases. Because DOTS emphasizes diagnosis by sputum-smear microscopy, 47 per cent of all new and relapse cases were smear-positive in DOTS areas, compared with 29 per cent elsewhere. Among the 15 countries with the highest estimated TB-incidence rates per capita, 12 are in Africa.

Financing for global TB control has improved dramatically in some countries since 2002. Some high-burden countries have sufficient funds, but must show they can spend them effectively; some have no apparent shortfall, but should verify that their budgets are sufficient to meet targets; and others have an obvious funding gap and must focus on raising the money needed to improve programme performance.

Source: WHO Fact Sheet No. 104, April 2005

Tuberculosis and HIV Facts

It is estimated that one third of the 40 million people living with HIV/AIDS worldwide are co-infected with tuberculosis. HIV-positive people are up to fifty times more likely to develop tuberculosis in a given year than those who are HIV-negative. Without proper treatment, approximately 90 per cent of those living with HIV die within months of contracting TB.

HIV/AIDS and TB are so closely connected that the term “co-epidemic” or “dual epidemic” is often used to describe their relationship. HIV affects the immune system and increases the likelihood of people acquiring new TB infection. It also promotes the progression of latent TB infection to an active disease and a relapse in previously treated patients. TB is a leading cause of death in HIV-infected people.

Each disease speeds up the progress of the other. TB considerably shortens the survival of people with HIV/AIDS and kills up to half of all AIDS patients worldwide.

HIV infection is the most potent risk factor for converting latent TB into active TB, while its bacteria accelerate the progress of AIDS infection.

According to the World Health Organization, TB infection is spreading at the rate of one person per second and kills more people than any other infectious disease; it is the world’s biggest killer of women. Every year, 8 million to 10 million people contract tuberculosis, while 2 million die from it. About one third of the global population carry the TB bacteria, but most never develop the disease. Around 10 per cent of people with TB actually develop the disease in their lifetime, but this proportion is changing as HIV severely weakens the human immune system and makes people much more vulnerable.

HIV/AIDS is dramatically fuelling the TB epidemic in sub-Saharan Africa, where up to 70 per cent of TB patients in some countries are co-infected with HIV. For many years, efforts to tackle TB and HIV have been largely separate, despite their overlapping epidemiology. Improved collaboration of programmes for both diseases will lead to a more effective TB control among HIV-infected people and to significant public health gains.

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