TB diagnosis: For now, still desperately seeking better diagnostics

This article is more than 13 years old. Click here for more recent articles on this topic

The audience’s response to all the talk about improving smear microscopy was mixed. Some felt that the combination of these approaches could achieve an impact similar to having a new more sensitive diagnostic test:

“I think by combining some of these ideas, that you know are very exciting, by collaborating we can push things forward to make it much easier for patients to get a diagnosis,” said Dr Fennally.

Others were guided by pragmatism. “I really think it’s unlikely that there are going to be new diagnostic tests that are a hundred percent sensitive, a hundred percent specific and we need to be thinking about combining tests in a way that is going to be intelligent and will supplement each other,” said one audience member.

Glossary

capacity

In discussions of consent for medical treatment, the ability of a person to make a decision for themselves and understand its implications. Young children, people who are unconscious and some people with mental health problems may lack capacity.

“We must try and get what diagnostics exist, out to improve the diagnosis of tuberculosis in whatever part of the world it is required. The only difficulty is that the systems required to operationalise some of these diagnostics - the capacity is not there at the moment, and it is unlikely to be a short process in building that capacity,” said Andy Ramsay. ”There’s likely to be a delay, whichever diagnostic we choose. So, I think a combination of approaches is required here, to make sure that every step of that process, we’re doing the best that we can.”

But others had a darker take on the subject:

“It’s not acceptable to say, “well we just have to tweak the smears” so that we can try to make the diagnosis for TB in the rest of the world when we know it’s just not acceptable. We need to demand more”, said Dr Carol Dukes Hamilton of Duke University.

“Let’s remember that a positive smear is very good, but it is delayed diagnosis,” said another member of the audience. “The future should be tests where we can pick patients within the week of infection, when you don’t expect them to be smear-positive.”

Other items in this series

TB diagnosis special report: why smear microscopy needs to be improved

Background on smear microscopy in TB diagnosis

TB diagnosis: Reducing the number of smears and clinic visits needed

TB diagnosis: Improving the yield with fluorescence microscopy

References

Anthony R and Kolk A. Light Emitting Diodes for sputum smear fluorescence microscopy. 37th Union World Conference on Lung Health, Paris, 2006.

Bonnet M et al. Improve direct microscopy by overnight bleach sedimentation: a simple tool for peripheral health centres. 37th Union World Conference on Lung Health, Paris, Abstract PC-61450-03, 2006.

Cambanis A et al. A one-day method for the diagnosis of pulmonary tuberculosis in rural Ethiopia. Int J Tuberc Lung Dis10(2):230-2, 2006.

Daru P et al. How can we reduce patient’s delay? 37th Union World Conference on Lung Health, Paris, Abstract PS-61419-03, 2006.

Eyangoh S et al. Does bleach concentration of sputum improve the sensitivity of smear-microscopy in HIV-positive patients? 37th Union World Conference on Lung Health, Paris, 2006.

Fennelly et al. Improved sensitivity of AFB microscopy using small membrane filters. 37th Union World Conference on Lung Health, Paris, Abstract PC-61912-03, 2006.

Githui WA et al. Combination of bleach and fluorescent microscopy enhances diagnosis of sputum smear-negative tuberculosis. 37th Union World Conference on Lung Health, Paris, Abstract PS-61447-03, 2006.

Hyder H et al. Tuberculosis control in metropolitan cities of Bangladesh. 37th Union World Conference on Lung Health, Paris, Abstract PS-61201-02, 2006.

Jian XW et al. The role of smear microscopy center at township level. 37th Union World Conference on Lung Health, Paris, Abstract PS-61591-04, 2006.

Klarkowski DB et al. The use of sputum cytology on Ziehl-Neelsen stained smears to improve pulmonary TB diagnosis. 37th Union World Conference on Lung Health, Paris, Abstract PC-61857-03, 2006.

Matiru R and Vrakking H. GDF Diagnostic Kits. 37th Union World Conference on Lung Health, Paris, 2006.

Matu S W et al. Improved diagnosis of Ziehl-Neelsen smear-negative tuberculosis using sodium hypochlorite sedimentation method. 37th Union World Conference on Lung Health, Paris, Abstract PS-61462-03, 2006.

Siddiqi K et al. Clinical and X-ray diagnosis of smear-negative pulmonary tuberculosis in low-income countries: the current evidence. 37th Union World Conference on Lung Health, Paris, 2006.

Squire SB et al. Using existing technologies and “one-stop approaches to improve the cost-effectiveness of TB case detection for the poor in Africa. 37th Union World Conference on Lung Health, Paris, 2006.

Steingart KR et al. Fluorescence versus conventional sputum smear microscopy for tuberculosis: a systemic review. Lancet Infect Dis:6:57-81, 2006.

Sultana S et al. Tuberculosis control in mega cities: Dhaka, Bangladesh. 37th Union World Conference on Lung Health, Paris, Abstract PS-61197-03, 2006.

Unnikrishnan K P et al. Economic analysis of health care seeking behaviour by TB patients in Bangalore, India. 37th Union World Conference on Lung Health, Paris, Abstract. PS-61836-04, 2006.

World Health Organization. Laboratory Services in Tuberculosis Control Part II: Microscopy. Geneva, Switzerland:World Health Organization, 1998.

WHO Stop TB Department, Department of HIV/AIDS TB/HIV: A Clinical Manual. 2nd edition. Geneva, Switzerland, 2004.

World Health Organisation. Stop TB Department, Department of HIV/AIDS, Improving the diagnosis and treatment of smear-negative pulmonary and extrapulmonary tuberculosis among adults and adolescents. Recommendations for HIV-prevalent and resource-constrained settings. WHO, Geneva, Switzerland, 2006.

Yassin MA et al. Same-day smear microscopy diagnosis of tuberculosis. 37th Union World Conference on Lung Health, Paris, 2006.

Related topics