Features | Partner Sites | Information | LinkXpress
Sign In
GLOBETECH PUBLISHING
JIB
GLOBETECH PUBLISHING

Rapid, Automated Test Accurately Detects Tuberculosis in Pediatric Samples

By BiotechDaily International staff writers
Posted on 08 Aug 2013
Image: The Xpert MTB/RIF test cartridge (Photo courtesy of Cepheid).
Image: The Xpert MTB/RIF test cartridge (Photo courtesy of Cepheid).
Image: The GeneXpert System loaded with a test cartridge (Photo courtesy of Cepheid).
Image: The GeneXpert System loaded with a test cartridge (Photo courtesy of Cepheid).
A team of South African investigators compared the effectiveness of a new, automated diagnostic test that simultaneously detects tuberculosis (TB) and rifampicin resistance to classical microscopy and culture methods in pediatric samples.

The World Health Organization (WHO) estimated that in 2011 alone more than 500,000 new cases of TB appeared with nearly 64,000 deaths among those younger than 15 years of age.

The authors of the current study collected nearly 1,500 paired sputum and nasopharyngeal specimens from 354 children who presented at a primary care clinic with symptoms of TB. The samples were analyzed with the Cepheid (Sunnyvale, CA, USA; www.cepheidinternational.com) Xpert MTB/RIF test, and the diagnostic accuracy of the results were compared with the reference standards of culture and smear microscopy.

The Xpert MTB/RIF Test detects both TB and rifampicin resistance high sensitivity even in smear negative, culture positive specimens. The test produces results in two hours and requires no instrumentation other than the GeneXpert System.

Cepheid's GeneXpert System is a closed, self-contained, fully integrated, and automated platform that combines on-board sample preparation with real-time PCR (polymerase chain reaction) amplification and detection functions for fully integrated and automated nucleic acid analysis. The system is designed to purify, concentrate, detect, and identify targeted nucleic acid sequences thereby delivering answers directly from unprocessed samples.

Results revealed that five children (1%) tested positive for tuberculosis by smear microscopy, 26 (7%) tested positive by Xpert MTB/RIF, and 30 (8%) tested positive by culture. Among children who did not in fact have the disease, the results of the Xpert test reported negative for TB with 99% accuracy. These findings suggest that Xpert MTB/RIF on respiratory secretions is a useful test for rapid diagnosis of pediatric pulmonary tuberculosis in primary care.

Dr. Fred Tenover, senior director of scientific affairs at Cepheid, said, "If you were to inoculate an Xpert MTB/RIF test at the same time you started preparing your acid fast smears, by the time you finished reading the smears, the Xpert MTB/RIF test result would be ready, telling you if your positive acid fast smear was TB and if the strain was resistant to rifampicin, which is an excellent surrogate marker for MDR (multiple drug resistant)-TB. I am sure Koch and Pasteur would not only be delighted with the technological advance, they would probably say, 'It is about time.'"

“There has been a perception amongst health care workers that rapid diagnosis of TB in children would not be possible in primary care, but this study disproves that view, said first author Dr. Heather Zar, professor of pediatrics at the University of Cape Town (South Africa; www.scah.uct.ac.za). “Given our results, widespread adoption of rapid testing for TB and drug resistance in children may substantially improve public health without greatly increasing costs.”

Results of the South African study were published in the August 2013 issue of the journal the Lancet Global Health.

Related Links:

Cepheid

University of Cape Town



comments powered by Disqus

Channels

Genomics/Proteomics

view channel
Image: A leukemia cell coated with antibody is marked for destruction by activated natural killer cells (Photo courtesy of the University of Southern California).

Leukemia Cells Are Killed in Culture by Immune Cells Grown from the Same Patient

Immune system natural killer (NK) cells were isolated from leukemia patients, expanded in culture, and then shown in an in vitro system to attack and destroy cancer cells from the original cell donors.... Read more

Drug Discovery

view channel
Image: Synthetic ion transporters can induce apoptosis by facilitating chloride anion transport into cells (Photo courtesy of the University of Texas, Austin).

Experimental Drug Kills Cancer Cells by Interfering with Their Ion Transport Mechanism

An experimental anticancer drug induces cells to enter a molecular pathway leading to apoptosis by skewing their ion transport systems to greatly favor the influx of chloride anions. To promote development... Read more

Therapeutics

view channel
Image: Liver cells regenerated in mice treated with a new drug (right) compared with a control group (center) after partial liver removal. Healthy liver cells are shown at left (Photo courtesy of Marshall et al, 2014, the Journal of Experimental Medicine).

New Drug Triggers Liver Regeneration After Surgery

Investigators have revealed that an innovative complement inhibitor decreases complement-mediated liver cell death, and actually stimulates postsurgery liver regrowth in mice. Liver cancer often results... Read more

Lab Technologies

view channel

White-Matter Deficits Found in Codeine-Containing Cough Syrup Users

A magnetic resonance imaging (MRI) study of chronic users of codeine-containing cough syrups (CCS) has found deficits in specific regions of brain white matter and linked these changes with increased impulsivity in codeine-containing cough syrup users. These findings were consistent with findings from earlier research of... Read more

Business

view channel

Partnership Established to Decode Bowel Disease

23andMe (Mountain View, CA,USA), a personal genetics company, is collaborating with Pfizer, Inc. (New York, NY, USA), in which the companies will seek to enroll 10,000 people with inflammatory bowel disease (IBD) in a research project designed to explore the genetic factors associated with the onset, progression, severity,... Read more
 
Copyright © 2000-2014 Globetech Media. All rights reserved.