Tuberculosis – the return of a killer

Although around 2 million people died as a result of tuberculosis (TB) in 2002, figures from the World Health Organization (WHO) on TB incidence and mortality reveal the contrast in how it affects industrialised and developing regions. For example, in 2002, Europe accounted for 4% of global deaths associated with TB, but in Africa the corresponding figure was just over 30% and in South-East Asia it was 34% (1).

The dangers of complacency

This ‘uneven impact’ that TB has around the world has meant that it has often slipped from being a major healthcare priority in industrialised countries - and this is confirmed by the poor media coverage and the general lack of understanding of the disease amongst the public.

In August 2004, health experts in the UK expressed concern that not enough was being done to halt the rise in TB cases around the country and warned that the seriousness of the situation was being underestimated (2). According to figures from the British Thoracic Society (BTS), concerning England and Wales, TB rates fell from 1913 until 1985, but since 1996 they have been increasing (3). In particular, since 2002, the number of TB cases reported in England and Wales has risen by 20% (2). This is a worrying situation as no other major EU country had experienced this type of rise. The BTS has called on the British government to invest more in basic measures to stop TB and to increase the number of specialist healthcare staff (2, 3).

Same disease, new problems

One of the problems in effectively dealing with TB is that the antibiotic drugs that were previously used are becoming less effective. Strains of TB bacilli that are resistant to single types of drugs have been reported in most countries and there are even some that are resistant to all major anti-TB drugs. WHO have estimated that the cost of treating drug-resistant forms of TB can be 100 times more than for the treatment of drug-susceptible TB.

There are also worrying trends in the way that TB is now affecting people worldwide.  In particular, healthcare agencies such as WHO have noted that HIV and TB form a lethal combination. TB has become a leading cause of death among people who are HIV-positive and it now accounts for about 13% of AIDS deaths worldwide (1). This has been a particular problem in Africa where HIV has been described as the single most important factor in the rise of TB over the past 10 years (1).

When compared to the data from developing regions co-infection rates due to the TB/HIV combination are low in industrialised countries, but health authorities recognise that it still remains a threat. For example, between 1991 and 1995, a serious outbreak of multidrug-resistant TB occurred at a Spanish hospital, which led to several deaths of HIV-positive patients (4).

To tackle the global combined TB/HIV threat, WHO set up a joint TB/HIV Working Group with other international organisations to develop policy and control measures. At its 3^rd Global Working Group meeting in June 2003 the common ground between HIV and TB was emphasised by using the theme “Two diseases – one patient” (5). At the 2004 International AIDS conference, Nelson Mandela highlighted the importance of tackling TB within the context of AIDS and it was announced the WHO was launching a new TB/HIV unit to deal with the problem (6).

Concerted action

The power of a dedicated approach in tackling TB has been shown by the WHO-approved DOTS ("directly-observed treatment, short-course") programme. In China, the programme has been a major success. Between 1991 and 2000, prevalence of TB in China fell by an estimated 30%, as a result of the DOTS project (7). The Government of China's National Tuberculosis Plan has expressed its intention to expand DOTS to 100% coverage of the country by 2005 (7). China hopes to achieve the United Nations Millennium Development Goal (MDG) of halving TB prevalence by 2015 (7).

In many areas of the world, particularly in industrialised countries, a degree of complacency appears to have set in that is hampering efforts by organisations to eradicate TB. Every year, The Stop TB Partnership, which is a partnership hosted by WHO, has been promoting World TB Day to try and raise the profile of TB and to encourage governments to cooperate to halt its spread (8). In 2004, World TB Day was held in New Delhi, India. The event involved delegations from 22 highest TB burden countries, as well as political representatives of the G8 countries (8). As has been seen for other diseases, international approaches provide the best means to effectively prevent and treat TB - and to make sure that the dangers it poses cannot be forgotten.

References

1.      Tuberculosis. World Health Organization (WHO) Fact Sheet N°104 Revised March 2004. http://www.who.int/mediacentre/factsheets/fs104/en/

2.      Fears over TB infection 'hotspot'. BBC News. 3 August 2004. http://news.bbc.co.uk/1/hi/england/london/3529032.stm

3.      World TB Day - Lack of specialist TB staff could lead to a further rise in tuberculosis - warn BTS. British Thoracic Society Press Release. 20 June 2003. http://www.brit-thoracic.org.uk/

4.      Multidrug-Resistant Tuberculosis Outbreak on an HIV Ward -- Madrid, Spain, 1991-1995. Centers for Disease Control and Prevention. Morbidity and Mortality Weekly Report. 45(16); 330-3. http://www.cdc.gov/mmwr/

5.      Two Diseases – One Patient. October 2003. World Health Organization (WHO). http://www.who.int/gtb/policyrd/TBHIV.htm

6.      McClean D (2004). Nelson Mandela Announces New TB/HIV Project by the Treatment Action Group. Dateline Bangkok. http://www.aids2004.org/

7.      Tuberculosis prevalence rates in China fall by 30% after introduction of the ‘DOTS’ strategy. 30 July 2004. World Health Organization Western Pacific Region. http://www.stoptb.org/go/wprodots

8.      World TB Day 2004. The Stop TB Partnership. http://www.stoptb.org/events/world_tb_day/2004/