Detecting Mycobacterium tuberculosis using the loop-mediated isothermal amplification test in South Africa.
Int J Tuberc Lung Dis
; 21(10): 1154-1160, 2017 10 01.
Article
in En
| MEDLINE
| ID: mdl-28911361
ABSTRACT
SETTING:
In South Africa, KwaZulu-Natal is the epicentre of the human immunodeficiency virus (HIV) epidemic, where approximately 70% of people with tuberculosis (TB) are co-infected with HIV. Undiagnosed TB contributes to high mortality in HIV-infected patients. Delays in diagnosing TB and treatment initiation result in prolonged transmission and increased infectiousness.OBJECTIVE:
To evaluate the LoopampTM MTBC Detection kit (TB-LAMP; based on the loop-mediated isothermal amplification assay), smear microscopy and Xpert test with the gold standard of mycobacterial culture.METHODS:
Sputum samples were collected from 705 patients with symptoms of pulmonary TB attending a primary health care clinic.RESULTS:
The TB-LAMP assay had significantly higher sensitivity than smear microscopy (72.6% vs. 45.4%, P < 0.001), whereas specificity was slightly lower (99% vs. 96.8%, P = 0.05), but significantly higher than Xpert (92.9%, P = 0.004). There was no significant difference in sensitivity of smear-positive, culture-positive and smear-negative, culture-positive sputum samples using TB-LAMP vs. Xpert (respectively 95.9%/55.9% vs. 97.6%/66.1%; P =0.65, P = 0.27). The positive predictive value of TB-LAMP was significantly higher than that of Xpert (87.5% vs. 77.0%; P = 0.02), but similar to that of smear microscopy (94.2%; P = 0.18). The negative predictive value was respectively 91.9%, 92.5% (P = 0.73) and 83.1% (P = 0.0001).CONCLUSION:
Given its ease of operability, the TB-LAMP assay could be implemented as a point-of-care test in primary health care settings, and contribute to reducing treatment waiting times and TB prevalence.
Full text:
1
Collection:
01-internacional
Health context:
2_ODS3
/
3_ND
/
4_TD
/
6_ODS3_enfermedades_notrasmisibles
Database:
MEDLINE
Main subject:
Sputum
/
Tuberculosis, Pulmonary
/
Nucleic Acid Amplification Techniques
/
Mycobacterium tuberculosis
Type of study:
Diagnostic_studies
/
Prevalence_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Female
/
Humans
/
Male
/
Middle aged
Country/Region as subject:
Africa
Language:
En
Journal:
Int J Tuberc Lung Dis
Year:
2017
Document type:
Article