Temperature affects the results of the glutaraldehyde test in the diagnosis of pulmonary tuberculosis.
METHODS
Subjects attending the District Tuberculosis Clinic and a Teaching Hospital in Jodhpur were studied at the Desert Medicine Research Centre, Jodhpur.


OBJECTIVE
To confirm the effect of temperature on the results of the blood glutaraldehyde test (GT) and to examine the sensitivity and specificity of the restandardised test procedure.


METHODS
Blood glutaraldehyde gelification time (BGGT) was compared, in the same blood samples, at 19, 22 and 25 degrees C and after storage at 1) room temperature and at 2) 2-8 degrees C for 3-5 h, using the paired t-test. After restandardisation of the procedure, the GT was carried out on 88 sputum culture-positive cases with pulmonary tuberculosis (PTB) and 182 controls. The technician was blinded to patient information.


RESULTS
BGGT significantly varied with the temperature of the water bath and the temperature at which blood samples were stored before testing. When the test was carried out in the water bath at 22 degrees C after storing blood for 3-5 h at 2-8 degrees C, as per the restandardised procedure, the specificity of GT was 96.2% (95 %CI 93.36-98.95) and the sensitivity was 84.1% (95%CI 76.45-91.73).


CONCLUSIONS
Restandardised GT is a reliable, simple, easy, rapid, inexpensive and user-friendly test for diagnosis of PTB which does not require sophisticated laboratory equipment.
Mathur
M L
ML
Desert Medicine Research Centre, Indian Council of Medical Research, Jodhpur, India. mmmurli@rediffmail.com
Sachdev
R
R
D001431:Bacteriological Techniques; D005976:Glutaral; D006801:Humans; D009169:Mycobacterium tuberculosis / Q000302:isolation & purification; D012680:Sensitivity and Specificity; D013048:Specimen Handling; D013696:Temperature; D014397:Tuberculosis, Pulmonary / Q000382:microbiology*
D005976:Glutaral