European Society of Mycobacteriology - Instituto Nacional de Saúde ...

IMPLEMENTATION OF THE THIN LAYER AGAR (TLA) FOR THE DIAGNOSIS OF
SMEAR NEGATIVE PULMONARY
TUBERCULOSIS IN A HIGH HIV PREVALENCE SETTING
Martin, Anandi 1 , Munga Waweru, Peter 2 , Babu Okatch, Fred 2 , Amondi Ouma, Naureen
2
, Bonte, Laurence 2 , Palomino, Juan Carlos 1 , Varaine, Francis 2 , Portaels, Françoise 1
1 - Institute of Tropical Medicine, Antwerp, Belgium
2 - Médecins Sans Frontières, Paris, France
PP-89
Early diagnosis of smear-negative pulmonary tuberculosis in countries with high incidence of TB/HIV co-infection is
crucial to limit the mortality and control the disease. The objective of this study was to evaluate the performance of a
low-cost method, the Thin Layer Agar (TLA), for the diagnosis of smear-negative patients compared to the gold standard
Löwenstein-Jensen method. TLA relies on microscopic detection of cording growth that is characteristic of M. tuberculosis
and is able to differentiate between M. tuberculosis and non-tuberculous mycobacteria. This prospective study
was performed in Homa Bay district Hospital in Kenya. Out of 1584 smear-negative sputum samples, 212 were positive
by LJ (13.5%) and 220 positive by TLA (14%). The sensitivity of LJ and TLA was 71% and 74 % respectively. With further
improvement for decreasing the contamination rate in both methods, TLA could become an affordable method for the
diagnosis of smear-negative tuberculosis in resource-limited settings allowing the simultaneous detection and identification
of M. tuberculosis, within 2 weeks.
European Society of Mycobacteriology | 30 th Annual Congress | July 2009 | Porto - Portugal
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