Laboratory investigations on the diagnosis of tuberculosis in the malnourished tribal population of melghat, India.
BACKGROUND
Malnutrition is a major risk factor for the development of tuberculosis (TB). In India, Melghat is among the tribal regions which consist of highest number of malnutrition cases. Because of the paucity of TB data from these malnourished areas there is an urgent need for the development and evaluation of improved TB diagnostic tests. In the present study, three in house developed diagnostic tests namely TB-Ag(antigen) ELISA, Adenosine deaminase (ADA) estimation and IS6110 polymerase chain reaction (PCR) assay were investigated for the detection of Mycobacterium tuberculosis (M. tb.) infection.


METHODS
For investigation, blood samples were collected from 128 study subjects from six villages of Melghat tribal area and evaluated using three in house developed assays, namely TB-Ag ELISA, ADA estimation and IS6110 PCR.


RESULTS
The TB-Ag ELISA method yielded 83% sensitivity and 94% specificity. The ADA and PCR assay gave a sensitivity of 61% and 49% and specificity of 62% and 98% respectively. A considerable good agreement of 82.81% (k=0.472) between TB-Ag ELISA and PCR was observed. The overall sensitivity of TB-Ag ELISA was significantly higher (p<0.05) than the ADA and PCR while PCR yielded highest specificity among all the three evaluated tests.


CONCLUSIONS
We concluded that the routine use of TB-Ag ELISA can be useful for screening of suspected TB patients in the malnourished population where sophisticated laboratory set up is difficult.
Biochemistry Research Laboratory, Central India Institute of Medical Sciences, Nagpur, Maharashtra, India.
Rajpal S
RS
Kashyap
Amit R
AR
Nayak
Hari M
HM
Gaherwar
Shraddha S
SS
Bhullar
Aliabbas A
AA
Husain
Seema D
SD
Shekhawat
Ruchika K
RK
Jain
Sonali S
SS
Gaikwad
Ashish R
AR
Satav
Hemant J
HJ
Purohit
Girdhar M
GM
Taori
Hatim F
HF
Daginawala
D000243:Adenosine Deaminase / Q000097:blood; D000293:Adolescent; D000328:Adult; D000942:Antigens, Bacterial; D002648:Child; D004269:DNA, Bacterial; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007194:India; D008297:Male; D044342:Malnutrition / Q000150:complications*; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D014376:Tuberculosis / Q000150:complications* / Q000175:diagnosis*; D055815:Young Adult
D000942:Antigens, Bacterial; D004269:DNA, Bacterial; D000243:Adenosine Deaminase