Corporate Banner
Satellite Banner
Molecular & Clinical Diagnostics
Scientific Community
Become a Member | Sign in
Home>News>This Article

Rapid Test Allows for Earlier Diagnosis of Tuberculosis in Children

Published: Thursday, July 25, 2013
Last Updated: Thursday, July 25, 2013
Bookmark and Share
A new test for diagnosing TB in children detects roughly two-thirds of cases identified by the current culture test, but in a fraction of the time.

The test, known as Xpert MTB/RIF, also detected five times the number of cases identified by examining specimens under the microscope, a preliminary method for diagnosis that is often performed as an initial test, but which must be verified by the culture test. 

Xpert MTB/RIF results from respiratory secretions were ready in 24 hours, on average, compared with an average of more than two weeks for the culture test used in the study, the researchers found.  Previous studies have shown that Xpert MTB/RIF is effective for diagnosing TB in adults and in children with  pronounced symptoms of TB who have been admitted to a hospital.  Diagnosing TB in children is more difficult than diagnosing it in adults, because children tend to have much lower levels of the TB bacteria than do adults.

The results of the current study indicated that the ease and speed of diagnosis would be useful for children seen in clinics in resource-limited countries, which often lack the resources for traditional testing that are available in hospitals.  The test also was able to identify children with drug resistant TB. In addition, the researchers found that Xpert can readily determine when treatment for tuberculosis is not appropriate.  Among children who did not in fact have TB, the results of the Xpert test came back negative for TB with 99 percent accuracy.

Xpert MTB/RIF was developed with funding from the NIH's National Institute of Allergy and Infectious Diseases. Testing of Xpert MTB/RIF in children was funded by NICHD.

Preliminary diagnosis of TB is often made by collecting a sample of lung secretions and examining the sample under a microscope to see if it contains the bacteria that cause TB.    A sample is also sent to a laboratory so the bacteria can be cultured and identified.  It may take as long as six weeks for the culture test to show a positive result.  Because, children have lower levels of infectious bacteria than do adults, it is more difficult to detectthe bacteria under a microscope and to grow it in a culture.  For this reason, accurately diagnosing TB in children has been difficult.

"The availability of this test in primary care settings can help children get appropriate treatment faster," said Lynne M. Mofenson, M.D., of the Maternal and Pediatric Infectious Disease Branch of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH institute that funded the study.  "Looking at a specimen under the microscope, often used for initial diagnosis of TB in adults, is very inaccurate in children." 

The Xpert MTB/RIF test also detects TB strains that are resistant to the drug rifampicin, allowing physicians to more accurately prescribe an appropriate treatment, said Carol Worrell, M.D., also of the NICHD's MPIDB.  This is particularly important in areas where drug-resistant TB is common, such as South Africa.

The World Health Organization estimated that in 2011 there were 500,000 TB cases and 64,000 deaths among those younger than 15 years. 

The study was led by first author Heather J. Zar, M.D., Ph.D., of the University of Cape Town and Red Cross War Memorial Children's Hospital, also in Cape Town, South Africa; and Mark P. Nicol, Ph.D, also of the University of Cape Town and  the South African National Health Laboratory Service at Groote Schuur Hospital, Cape Town. 

The findings appear in The Lancet Global Health.

"There has been a perception amongst health care workers that rapid diagnosis of TB in children wouldn't be possible in primary care, but this study disproves that view, Dr. Zar said.  "Given our results, widespread adoption of rapid testing for TB and drug resistance in children may substantially improve public health without greatly increasing costs."

Dr. Zar and her colleagues collected almost 1500 samples from nearly 400 children who went to a primary care clinic with symptoms of TB.  Collecting the samples -- secretions from the lungs, the nasal passages or both -- requires special equipment and trained clinical staff.  The researchers compared the results from the Xpert MTB/RIF test, examination of samples under a microscope, and from growing the tuberculosis bacteria in laboratory cultures.  Bacterial culture is the most accurate method for diagnosing TB.

Of the 30 TB cases detected by culture, 19 (63 percent) were positive by the Xpert MTB/RIF test on lung or nasal samples, while examining the samples under the microscope turned up only four cases (13 percent).  Adding a second test (of a second lung or nasal passage sample) improved the detection rate for both culture and Xpert MTB/RIF 

In some cases, researchers started TB treatment for children they suspected had TB based on their symptoms.  Xpert MTB/RIF identified seven children who had clinical symptoms of tuberculosis and responded well to treatment for tuberculosis, but whose tuberculosis had not been detected by the tuberculosis culture test.  This might occur when a child is sick with TB, but the bacteria are at especially low levels, or because a sample did not contain enough of the bacteria present in the child's body to appear when cultured, Dr. Mofenson explained.  The total number of cases detected by culture (30 cases) and by XpertMTB/RIF (26 cases) was similar. 

"Because of the global burden of this disease among children, it's vital to make rapid, accurate diagnostic tests available in primary care settings in order to identify the disease and start treatment before children end up in the hospital," said Dr. Worrell.  "NICHD recognizes the value of supporting research to improve the accuracy of TB diagnosis in children, reduce the number of samples required, and make diagnostic tools widely accessible."

Further Information
Access to this exclusive content is for Technology Networks Premium members only.

Join Technology Networks Premium for free access to:

  • Exclusive articles
  • Presentations from international conferences
  • Over 2,800+ scientific posters on ePosters
  • More than 4,000+ scientific videos on LabTube
  • 35 community eNewsletters

Sign In

Forgotten your details? Click Here
If you are not a member you can join here

*Please note: By logging into you agree to accept the use of cookies. To find out more about the cookies we use and how to delete them, see our privacy policy.

Related Content

$21M Invested in Research Hubs in Developing Countries
The National Institutes of Health and other U.S. and Canadian partners are investing $20.9 million dollars over five years to establish seven regional research and training centers in low- and middle-income countries (LMICs).
Friday, October 09, 2015
Scientists Create World’s Largest Catalog of Human Genomic Variation
An international team of scientists from the 1000 Genomes Project Consortium has created the world’s largest catalog of genomic differences among humans, providing researchers with powerful clues to help them establish why some people are susceptible to various diseases.
Thursday, October 01, 2015
NIH Framework Points The Way Forward For Developing The President’s Precision Medicine Initiative
The NIH Advisory Committee to the Director has presented to NIH Director Francis S. Collins, M.D., Ph.D., a detailed design framework for building a national research participant group, called a cohort, of 1 million or more Americans to expand our knowledge and practice of precision medicine.
Monday, September 21, 2015
Undiagnosed Diseases Network Launches Online Application Portal
UDN Gateway enables patients to apply to national network of clinical sites.
Thursday, September 17, 2015
Using Genetic Sequencing to Manage Cancer in Children
A team of scientists have investigated the feasibility of incorporating clinical sequencing information into the care of young cancer patients.
Tuesday, September 15, 2015
Hastings Center Awarded NIH Grant
Funding has been awarded for a major project on goals and practices of next-generation prenatal testing.
Monday, September 14, 2015
NIH Grants Seek Best Ways To Combine Genomic Information and EHRs
Researchers seek to better understand genomic basis of disease, provide tailored care to patients.
Friday, September 04, 2015
Tumor DNA in Blood Reveals Lymphoma Progression
Using an advanced genetic test, researchers were able to detect diffuse large B-cell lymphoma (DLBCL) in blood serum before it could be seen on CT scans.
Tuesday, April 14, 2015
NIH Funds Nine Antimicrobial Resistance Diagnostics Projects
Investigators to develop tools to detect hospital-associated pathogens.
Friday, April 10, 2015
NIH Launches Tool to Advance Down Syndrome Research
Web portal will help approved professionals to plan clinical studies.
Wednesday, January 28, 2015
Sophisticated HIV Diagnostics Adapted For Remote Areas
New tool is low-cost, with no electricity needed.
Tuesday, December 02, 2014
NIH Names New Clinical Sites in Undiagnosed Diseases Network
Four-year, $43 million initiative engages broad expertise in study of mystery conditions.
Wednesday, July 02, 2014
Genetic Disorder Causing Strokes, Vascular Inflammation in Children Discovered
NIH researchers have identified gene variants that cause a rare syndrome of sporadic fevers, skin rashes and recurring strokes, beginning early in childhood.
Thursday, February 20, 2014
NIH, Industry and Non-Profits Join Forces to Speed Validation of Disease Targets
Goal is to develop new treatments earlier, beginning with Alzheimer's, type 2 diabetes, and autoimmune disorders.
Tuesday, February 11, 2014
Speeding Validation of Disease Targets
NIH, industry and non-profits join forces to develop new treatments earlier, beginning with Alzheimer’s, type 2 diabetes, and autoimmune disorders.
Tuesday, February 04, 2014
Scientific News
Mathematical Model Forecasts the Path of Breast Cancer
Chances of survival depend on which organs breast cancer tumors colonize first.
Measuring microRNAs in Blood to Speed Cancer Detection
A simple, ultrasensitive microRNA sensor holds promise for the design of new diagnostic strategies and, potentially, for the prognosis and treatment of pancreatic and other cancers.
Biomedical Imaging at One-Thousandth the Cost
Mathematical modeling enables $100 depth sensor to approximate the measurements of a $100,000 piece of lab equipment.
Improving Outcomes for Lung Cancer and Diabetic Patients
Novel technologies have been developed with support from SBRI Healthcare funding.
New Way of Detecting Cancer
A new RNA test of blood platelets can be used to detect, classify and pinpoint the location of cancer by analysing a sample equivalent to one drop of blood.
Rapid, Portable Ebola Diagnostic
Scientists confirmed the efficiency of the novel Ebola detection method in field trials.
New, Better Test for Prostate Cancer
A study from Karolinska Institutet shows that a new test for prostate cancer is better at detecting aggressive cancer than PSA.
Blood Test Picks Out Prostate Cancer Drug Resistance
Scientists have developed a blood test that can identify key mutations driving resistance to a widely used prostate cancer drug, and identify in advance patients who will not respond to treatment.
Antibody Targets Key Cancer Marker
University of Wisconsin-Madison researchers have created a molecular structure that attaches to a molecule on highly aggressive brain cancer and causes tumors to light up in a scanning machine.
Key Piece of MRSA Vaccine Puzzle
New research funded by the Health Research Board and the Wellcome Trust has pinpointed immune cells that could be targeted by an MRSA vaccine.
Skyscraper Banner

Skyscraper Banner
Go to LabTube
Go to eposters
Access to the latest scientific news
Exclusive articles
Upload and share your posters on ePosters
Latest presentations and webinars
View a library of 1,800+ scientific and medical posters
2,800+ scientific and medical posters
A library of 2,500+ scientific videos on LabTube
4,000+ scientific videos